Miscanthus giganteus

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Miscanthus x giganteus
Miscanthus Bestand.JPG
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Miscanthus giganteus (miscanthus giganteus, giant miscanthus, elephant grass)[1] is a sterile hybrid of Miscanthus sinensis and Miscanthus sacchariflorus.[2] It can grow to heights of more than 4 metres (13 ft) in one growing season (from the third season onwards). Just like Pennisetum purpureum and Saccharum ravennae it is also called elephant grass.

M. x giganteus' perennial nature,[3] its ability to grow on marginal land, its water efficiency, non-invasiveness, low fertilizer needs, significant carbon sequestration and high yield have sparked a lot of interest among researchers, with some arguing that it has «ideal» energy crop properties.[4] Some argue that it has the potential to be a GHG (greenhouse gas) negative fuel, while others highlight its water cleaning and soil enhancing qualities. There are practial and economic challenges related to its use in the existing, fossil based combustion infrastructure, however. Torrefaction and other fuel upgrading techniques are being explored as countermeasures to this problem.

Use areas[edit]

M. x giganteus is mainly used as raw material for solid biofuels. It can be burned directly, or processed further into pellets or briquettes. It can also be used as raw material for liquid biofuels or biogas.

It is possible to use Miscanthus as a building material, and as insulation.[5] Materials produced from Miscanthus include fiberboards, composite Miscanthus/wood particleboards, and blocks.[6] It can be used as raw material for pulp and fibers. Miscanthus has a pulp yield of 70-80% compared to dry weight, due to the high holocellulose content. The pulp can be processed further into methylcellulose and used as a food additive and in many industrial applications. Miscanthus fiber provides raw material for reinforcement of biocomposite or synthetic materials.[7] In agriculture, Miscanthus straw is used in soil mulching to retain soil moisture, inhibit weed growth, and prevent erosion. Further, Miscanthus' high carbon to nitrogen ratio makes it inhospitable to many microbes, creating a clean bedding for poultry, cattle, pigs, horses, and companion animals. Miscanthus used as horse bedding can be combined with making organic fertilizer.[8]

Life cycle[edit]

Propagation[edit]

Bamboo rhizome

Miscanthus x giganteus is propagated by cutting the rhizomes (its underground stems) into small pieces, and then re-planting those pieces 10 cm (4 in) underground. One hectare (2.5 acres) of Miscanthus rhizomes, cut into pieces, can be used to plant 10-30 hectares of new Miscanthus fields (multiplication factor 10-30).[9] Rhizome propagation is a labor intensive way of planting new crops, but only happens once during a crop's lifetime. New and cheaper propagation techniques is underway, which seem to increase the multiplication factor from 10-30 to 1000-2000.[10][11] A halving of the cost is predicted.[12]

Management[edit]

A limited amount of herbicide should only be applied at the beginning of the first two seasons; after the second year the dense canopy and the mulch formed by dead leaves effectively reduces weed growth.[13] Other pesticides are not needed.[14] Because of Miscanthus' high nitrogen efficiency,[15] fertilizer is also usually not needed.[16][17] Mulch film, on the other hand, helps both M. x giganteus and various seed based hybrids to grow faster and taller, with a larger number of stems per plant, effectively reducing the establishment phase from three years to two.[18][19] The reason seems to be that this plastic film keeps the humidity in the topsoil and increases the temperature.[20]

Yield - overview[edit]

Young miscanthus test crop in England.

Miscanthus x giganteus is close to the theoretical maximum efficiency at turning solar radiation into biomass,[21] and its water use efficiency is among the highest of any crop.[22] It has twice the water use efficiency as its fellow C4 plant maize, and four times the efficiency as the C3 plant wheat.[23] This means that Miscanthus x giganteus fields are energy dense - at 18 GJ per dry tonne, a typical UK dry yield of 11-14 tonnes per hectare produce 200-250 GJ ha-1 yr-1 (gigajoules per hectare per year). This compares favorably to maize (98 GJ), oil seed rape (25 GJ), and wheat/sugar beet (7-15 GJ),[24] underlining the differences between first and second generation bioenergy crops.

In Europe the dry mass yield is 10–40 tonnes per hectare per year (4–16 tonnes per acre per year), depending on location.[25] The mean annual dry mass yield for the European Union has been estimated to be 18,8 tonnes, or 338 GJ per hectare per year (18 GJ per dry tonne). (Using the imperial system: 7.6 tonnes, or 137 GJ per acre per year.)[26] European yields are highest in southern Europe. Trials in Illinois, USA, had yields 10–15 tonnes per acre (25–37 t/ha). Like Europe, yields decrease as you move north. M. x giganteus has been shown to yield two to three times more than switchgrass and corn stover.[27]

Maximum yield is reached at the end of summer but harvest is typically delayed until winter or early spring. Yield is lower at this point because of leaves drop, but the combustion quality is higher. Delayed harvest also allows nitrogen to move back into the rhizome for use by the plant in the following growing season.

Yield - arable land[edit]

Planting and harvest (video).

In Germany, Felten et al. did a 16 year trial on arable land and concluded with a mean yield of 15 tonnes per hectare per year (6.1 tonnes per acre per year).[28] McCalmont et al. estimates a mean UK yield of 10-15 tonnes,[29] while Hastings et al. estimates a «pessimistic» UK mean yield of 10.5 tonnes.[30] Nsanganwimana et al. summarizes several trials, and give these numbers: Austria: Autumn harvest 17-30. Winter harvest 22. Denmark: Autumn harvest 17. Winter harvest 10. France: Autumn harvest 42-49. Winter harvest 30. Germany: Autumn harvest 17-30. Winter harvest 10-20. Portugal: Autumn harvest 39. Winter harvest 26-30. The Netherlands: Autumn harvest 25. Winter harvest 16-17. Spain: Winter harvest 14. UK: Winter harvest 11-17.[31]

Yield - marginal land[edit]

Steep, marginal land.

Marginal land is land with issues that limits growth, for instance low water and nutrient storage capacity, high salinity, toxic elements, poor texture, shallow soil depth, poor drainage, low fertility, or steep terrain. Depending on how the term is defined, between 1.1 and 6.7 billion hectars of marginal land excists in the world.[32] For comparison, Europe consists of roughly 1 billion hectares (10 million km2, or 3.9 million square miles), and Asia 4.5 billion hectares (45 million km2, or 17 million square miles).

Quinn et al. identified Miscanthus x giganteus as a crop that is moderately or highly tolerant of multiple environmental stressors, specifically, heat, drought, flooding, salinity (below 100 mM), and cool temperatures (down to −3.4 °C, or 25 °F).[33] This robustness makes it possible to establish relatively high-yielding Miscanthus fields on marginal land, Nsanganwimana et al. mentions wastelands, coastal areas, damp habitats, grasslands, abandoned milling sites, forest edges, streamsides, foothills and mountain slopes as viable locations.[34] Likewise, Stavridou et al. concluded that 99% of Europe's saline, marginal lands can be used for M. x giganteus plantations, with only an expected maximum yield loss of 11%.[35] Since salinity up to 200 mM does not affect roots and rhizomes, carbon sequestration carry on unaffected.[36] Lewandowski et al. found a yield loss of 36% on a marginal site limited by low temperatures (Moscow), compared to maximum yield on arable land in central Europe. They also found a yield loss of 21% on a marginal site limited by drought (Turkey), compared to maximum yields on arable soil in central Europe.[37] Further, Nsanganwimana et al. found that M. x giganteus grows well in soils contaminated by metals, or by industrial activities in general.[38] For instance, in one trial, it was found that M. x giganteus absorbed 52% of the lead content and 19% of the arsenic content in the soil after three months.[39] The absorption stabilizes the pollutants so they don't travel into the air (as dust), into ground water, neighbouring surface waters, or neighbouring areas used for food production.[40] If contaminated Miscanthus is used as fuel, the combustion site need to install the appropriate equipment to handle this situation.[41] On the whole though, «[…] Miscanthus is [a] suitable crop for combining biomass production and ecological restoration of contaminated and marginal land.»[42] Clifton-Brown et al. concludes that Miscanthus x giganteus can «[…] contribute to the sustainable intensification of agriculture, allowing farmers to diversify and provide biomass for an expanding market without compromising food security.»[43]

Carbon sequestration[edit]

Soil carbon input/output[edit]

At the end of each season, the plant pulls the nutrients to the ground. The color shifts from green to yellow/brown.

Plants sequester carbon through photosynthesis, by exchanging O2 (oxygen) for CO2, thus keeping the carbon (C) to itself. When the plants move carbon to the roots, it does not stay down there forever however; «[…] soil carbon is a balance between the decay of the initial soil carbon and the rate of input […].»[44][45] Plant derived soil carbon is a continuum, ranging from living biomass to humus,[46] and it decays in different stages, ranging from months (decomposable plant material; DPM) to hundreds of years (humus). The rate of decay depends on many factors, for instance plant species, soil, temperature and humidity,[47] but as long as fresh new carbon is inputted, a certain amount of carbon stay in the ground – in fact Poeplau et al. did not find any «[…] indication of decreasing SOC [soil organic carbon ] accumulation with age of the plantation indicating no SOC saturation within 15–20 years.»[48] The amount of carbon in the ground under Miscanthus fields is thus seen to increase during the entire life of the crop, albeit with a slow start because of the initial tilling (plowing, digging) and the relatively low amounts of carbon input in the establishment phase.[49][50] (Tilling induces soil aeration, which accelerates the soil carbon decomposition rate, by stimulating soil microbe populations. Also, tilling makes it easier for the oxygen (O) atoms in the atmosphere to attach to carbon (C) atoms in the soil, producing CO2). [51] Felten et al. argues that high proportions of pre- and direct-harvest residues (e.g. dead leaves), direct humus accumulation, the well-developed and deep-reaching root system, the low decomposition rates of plant residues due to a high C : N ratio (carbon to nitrogen ratio), and the absence of tillage and subsequently less soil aeration are the reasons for the high carbon sequestration rates.[52]

Net annual carbon accumulation[edit]

A number of studies try to quantify the net amount of below-ground carbon accumulation each year, after decay is accounted for, in various locations and under various circumstances.

Dondini et al. found 32 tonnes more carbon per hectare (13 tonnes per acre) under a 14 year old Miscanthus field than in the control site, suggesting a combined (C3 plus C4) accumulation rate of 2.29 tonnes per hectare (0.91 long ton/acre), or 38% of total harvested carbon per year.[53] Likewise, Milner et al. suggest a mean carbon accumulation rate for the whole of the UK of 2.28 tonnes per hectare (0.91 long ton/acre) per year (also 38% of total harvested carbon per year), given that some unprofitable land (0.4% of total) is excluded.[54] Nakajima et al. found an accumulation rate of 1.96  (±  0.82) tonnes per hectare per year below a university test site in Sapporo, Japan (0.79 per acre), equivalent to 16% of total harvested carbon per year. The test was shorter though, only 6 years.[55] Hansen et al. found an accumulation rate of 0.97 tonne per hectare per year (0.39 tonnes per acre per year) over 16 years under a test site in Hornum, Denmark, equivalent to 28% of total harvested carbon per year.[56] McCalmont et al. compared a number of individual European reports, and found accumulation rates ranging from 0.42 to 3.8 tonnes per hectare per year,[57] with a mean accumulation rate of 1.84 tonne (0.74 tonnes per acre per year),[58] or 20% of total harvested carbon per year.[59]

Transport and combustion challenges[edit]

Overview[edit]

Roasted (torrefied) coffee beans.

Biomass in general, including Miscanthus x giganteus, have different properties compared to coal, for instance when it comes to handling and transport, grinding, and combustion.[60] This makes sharing the same logistics, grinding and combustion infrastructure difficult. Often new biomass handling facilities have to be built instead, which increases cost. Together with the relatively high cost of feedstock, this often lead to the well-known situation where biomass projects has to receive subsidies to be economically viable.[61] A number of fuel upgrading technologies are currently being explored however that makes biomass more compatible with the existing infrastructure. The most mature of these is torrefaction, basically an advanced roasting technique which – when combined with pelleting or briquetting – significantly influences both the handling and transport properties, grindability and combustion efficiency.

Energy density and transport costs[edit]

Transport of bulky, water absorbing Miscanthus bales in England.

Miscanthus bales and chips have a bulk density of approximately 150 kg/m3,[62] while briquettes have a bulk density of up to 600 kg/m3.[63] Torrefaction increases bulk density further, as approximately two thirds of the original mass is retained as a solid product, while approximately one third of the original mass was converted to gas during the process. The finished, torrefied, solid product, in the form of pellets or briquettes, still contains approximately 85% of the original energy, however.[64] Basically the mass part reduce more than the energy part, and the consequence is that the calorific value of torrefied biomass approaches that of medium grade coal - typically the calorific value increases from 18 GJ per tonne dry mass to 23 GJ per tonne torrefied mass.

The higher energy density means lower transport costs, and a decrease in transport-related GHG emittance.[65] The IEA (International Energy Agency) has calculated energy and GHG costs for regular and torrefied pellets/briquettes. When making pellets and shipping them from Indonesia to Japan, a minimum 6.7% of energy savings or 14% GHG savings is expected when switching from regular to torrefied. This number increases to 10.3% energy savings and 33% GHG savings when making and shipping minimum 50mm briquettes instead of pellets.[66] The longer the route, the bigger the savings. The relatively short supply route from Russia to the UK equals energy savings of 1.8%, while the longer supply route from southeast USA to the Amsterdam-Rotterdam-Antwerp (ARA) area is 7.1%. From southwest Canada to ARA 10.6%, southwest USA to Japan 11%, and Brazil to Japan 11.7% (all these savings are for pellets only.)[67]

Water absorption and transport costs[edit]

Torrefaction also converts the biomass from a hydrophilic (water absorbing) to a hydrophobic (water repelling) state. Water repelling briquettes can be transported and stored outside, which simplifies the logistics operation and decreases cost.[68] Almost all biological activity is stopped, reducing the risk of fire and biological decomposition like rotting.[69]

Uniformity and customization[edit]

Generally, torrefaction is seen as a gateway for converting a range of very diverse feedstocks into a uniform and therefore easier to deal with fuel.[70] The fuel's parameters can be changed to meet customers demands, for instance durability, water resistance, ash composition, torrefaction degree, geometrical form, and type of feedstock.[71] The possibility to use different types of feedstock improves the fuel's availability and supply reliability.[72]

Grindability[edit]

Coal grinders

Unprocessed M. x giganteus has strong fibers, making grinding into equally sized, very small particles (below 75 µm / 0.075 mm) difficult to achieve. Coal chunks are typically grinded to that size because such small, even particles combust stabler and more efficient than the larger fuel chunks.[73][74] While coal has a score on the Hardgrove Grindability Index (HGI) of 30-100 (higher numbers means it is easier to grind), unprocessed Miscanthus has a score of 0.[75] During torrefaction however, «[…] the hemi-cellulose fraction which is responsible for the fibrous nature of biomass is degraded, thereby improving its grindability.»[76] Bridgeman et al. measured a HGI of 79 for torrefied Miscanthus,[77] while the IEA estimates a HGI of 23-53 for torrefied biomass in general.[78] UK coal scores between 40 and 60 on the HGI scale.[79] The IEA estimates an 80-90% drop in energy use required to grind biomass that has been torrefied.[80]

The relatively easy grinding of torrefied Miscanthus makes a cost-effective conversion to fine particles possible, which subsequently makes efficient combustion with a stable flame possible. Ndibe et al. found that the level of unburnt carbon «[…] decreased with the introduction of torrefied biomass», and that the torrefied biomass flames «[…] were stable during 50% cofiring and for the 100% case as a result of sufficient fuel particle fineness.»[81]

Chlorine and corrosion[edit]

Corrosion of a nail.
Fouling on water intake.
Slag from furnace.

Raw miscanthus biomass has a relatively high chlorine amount, which is problematic in a combustion scenario because, as Ren et al. explains, the «[…] likelihood of corrosion depends significantly on the content of chlorine in the fuel […].»[82] Likewise, Johansen et al. states that «[…] the release of Cl-associated [chlorine-associated] species during combustion is the main cause of the induced active corrosion in the grate combustion of biomass.»[83] Chlorine in different forms, in particular combined with potassium as potassium chloride, condensates on relatively cooler surfaces inside the boiler and creates a corrosive deposit layer. The corrosion damages the boiler, and in addition the physical deposit layer itself reduce heat transfer efficiencey, most critically inside the heat exchange mechanism.[84] Chlorine and potassium also lowers the ash melting point considerably compared to coal. Melted ash, known as slag or clinker, sticks to the bottom of the boiler, and increase maintenance costs.[85][86][87]

In order to reduce chlorine (and moisture) content, M. x giganteus is usually harvested dry, in early spring, but this late harvest practice is still not enough of a countermeasure to achieve corrosion-free combustion.[88]

However, Ren et al. found that «[…] 59.1 wt%, 60.7 wt% and 77.4 wt% of the chlorine contents of olive residues, DDGS and corn straw, respectively, were released during torrefaction»,[89] and concludes that chlorine emissions «[…] were drastically lower, by 2–5 times, than those of their raw biomass precursors.»[90] Chlorine release during the torrefaction process itself is more manageble than chlorine release during combustion, because «[…] the prevailing temperatures during the former process are below the melting and vaporization temperatures of the alkali salts of chlorine, thus minimizing their risks of slagging, fouling and corrosion in furnaces[91]

For potassium, Kambo et al. found a 30% reduction for torrefied miscanthus, while Ren et al. found an 86% increase for torrefied corn stover.[92] However, potassium is dependent on chlorine to form potassium chloride; with a low level of chlorine, the potassium chloride deposits reduce proportionally.[93]

Conclusion[edit]

Li et al. concludes that the «[…] process of torrefaction transforms the chemical and physical properties of raw biomass into those similar to coal, which enables utilization with high substitution ratios of biomass in existing coal-fired boilers without any major modifications.»[94] Likewise, Bridgeman et al. states that since torrefaction removes moisture, creates a grindable, hydrophobic and solid product with an increased energy density, torrefied fuel no longer requires «[…] separate handling facilities when co-fired with coal in existing power stations.»[95] Smith et al. makes a similar point in regard to hydrothermal carbonization, sometimes called «wet» torrefaction.[96]

Ribeiro et al. note that «[…] torrefaction is a more complex process than initially anticipated» and states that «[…] torrefaction of biomass is still an experimental technology […].»[97] Michael Wild, president of the International Biomass Torrefaction Council,[98] stated in 2015 that the torrefaction sector is «[…] in its optimisation phase […]», i.e. it is maturing. He mentions process integration, energy and mass efficiency, mechanical compression and product quality as the variables most important to master at this point in the sector's development.[99]

Environmental impacts[edit]

GHG savings[edit]

Yield and soil carbon content[edit]
GHG / CO2 / carbon negativity for Miscanthus x giganteus production pathways.
Relationship between above-ground yield (diagonal lines), soil organic carbon (X axis), and soil's potential for successful/unsuccessful carbon sequestration (Y axis). Basically, the higher the yield, the more land is usable as a GHG mitigation tool (including relatively carbon rich land.)

The amount of carbon sequestrated and the amount of GHG (greenhouse gases) emitted will determine if the total GHG life cycle cost of a bio-energy project is positive, neutral or negative. Whitaker et al. estimates that for Miscanthus x giganteus, carbon neutrality and even negativity is within reach. A carbon negative life cycle is possible if the total below-ground carbon accumulation more than compensates for the above-ground total life-cycle GHG emissions. The graphic on the right displays two CO2 negative Miscanthus x giganteus production pathways, represented in gram CO2-equivalents per megajoule. The yellow diamonds represent mean values.[100] Successful sequestration is dependent on planting sites, as the best soils for sequestration are those that are currently low in carbon. The varied results displayed in the graph highlights this fact.[101] For the UK, successful sequestration is expected for arable land over most of England and Wales, with unsucessful sequestration expected in parts of Scotland, due to already carbon rich soils (existing woodland) plus lower yields. Soils already rich in carbon includes peatland and mature forest. Grassland can also be carbon rich, however Milner et al. argues that the most successful carbon sequestration in the UK takes place below improved grasslands.[102] The bottom graphic displays the estimated yield necessary to compensate for the disturbance caused by planting plus lifecycle GHG-emissions for the related above-ground operation.

The two main advantages Miscanthus x giganteus has as a GHG mitigation tool is the below ground growth rate (see carbon sequestration, above) and the fact that it is a perennial rather than an annual crop. The perennial nature of the crop means that the significant below-ground carbon accumulation each year is allowed to continue to increase, undisturbed. No annual plowing or digging means no increased carbon oxidation and no stimulation of the microbe populations in the soil, and therefore no accelerated carbon-to-CO2 conversion happening in the soil every spring.

The below-ground carbon accumulation works as a GHG mitigation tool because it removes CO2 from the above-ground CO2 circulation (plant to atmosphere and back into plant.)[103] The above-ground cycle has the potential to be carbon neutral, but of course the human involvment in the process means additional energy input, often coming from fossil sources. If the fossil energy spent on the operation is high compared to the operation's energy output, the CO2 footprint can approach, match or even exceed the CO2 footprint from burning fossil fuels directly.[104][105][106] Transport fuels might be worse than solid fuels in this regard.[107]

Savings comparison[edit]

The problem can be dealt with both from the perspective of increasing the amount of carbon that is moved below ground (see carbon sequestration, above), and from the perspective of decreasing fossil fuel input to the above-ground operation. If enough carbon is moved below ground, it can compensate for a bio-energy project's total CO2 emittance. On the other hand, if the above-ground CO2 cost decreases, less below-ground carbon allocation is needed for the bioenergy project to become CO2 neutral.

For first generation bio-energy crops, the greenhouse gas footprints were often large, but second generation bio-energy crops like Miscanthus reduces its CO2 footprint drastically. Hastings et al. found that Miscanthus crops «[…] almost always has a smaller environmental footprint than first generation annual bioenergy ones [...].»[108] Compared to fossil fuels, the savings are large – without compensating for carbon sequestration, Miscanthus fuel has a GHG cost of 0.4 - 1.6 grams CO2-equivalents per megajoule, compared to 33 grams for coal, 22 for liquefied natural gas, 16 for North Sea gas, and 4 for wood chips imported to Britain from the USA.[109]

Confirming the above numbers, McCalmont et al. found that the mean energy input/output ratios for Miscanthus is 10 times better than for annual crops, while GHG costs are 20-30 times better than for fossil fuels.[110] For instance, Miscanthus chips for heating saved 22.3 tonnes of CO2 emittance per hectare per year in the UK (9 tonnes per acre), while maize for heating and power saved 6.3 (2.5 per acre). Rapeseed for biodiesel saved only 3.2 (1.3 per acre).[111] Lewandowski et al. found that each hectare (2.47 acres) of Central European arable land planted with Miscanthus can reduce the atmospheric CO2 level with up to 30.6 tonnes per year, save 429 GJ of fossil energy used each year, with 78 euros earned per tonne reduced CO2 (2387 euros earned per hectare per year) – given that the biomass is produced and used locally (within 500 km / 310 miles).[112] For Miscanthus planted on marginal land limited by cold temperatures (Moscow), the reduction in atmospheric CO2 is estimated to be 19.2 tonnes per hectare per year (7.7 tonnes per acre), with fossil energy savings of 273 GJ per hectare per year (110 GJ per acre). For marginal land limited by drought (Turkey), the atmospheric CO2 level can potentially be reduced with 24 tonnes per hectare per year (9.7 tonnes per acre), with fossil energy savings of 338 GJ per hectare per year (137 tonnes per acre).[113] Based on similar numbers, Poeplau and Don expect Miscanthus plantations to grow large in Europe in the coming decades.[114] Whitaker et al. states that after some discussion, there is now (2018) consensus in the scientific community that «[…] the GHG balance of perennial bioenergy crop cultivation will often be favourable […]», also when considering the implicit direct and indirect land use changes.[115]

Biodiversity[edit]

Earthworm
Skylark

Felten and Emmerling found that the number of earthworm species per square meter was 5.1 for Miscanthus, 3 for maize, and 6,4 for fallow (totally unattended land), and states that «[…] it was clearly found that land-use intensity was the dominant regressor for earthworm abundance and total number of species.» Because the extensive leaf litter on the ground helps the soil to stay moist, and also protect from predators, they conclude that «[…] Miscanthus had quite positive effects on earthworm communities […]» and recommend that «[…] Miscanthus may facilitate a diverse earthworm community even in intensive agricultural landscapes.»[116][117]

Nsanganwimana et al. found that the bacterial activity of certain bacteria belonging to the proteobacteria group almost doubles in the presence of M. x giganteus root exudates.[118]

Lewandowski et al. found that young Miscanthus stands sustain high plant species diversity, but as the Miscanthus stands mature, the canopy closes, and less sunlight reach the ground. In this situation it gets harder for the weeds to survive. Lewandowski et al. found 16 different weed species per 25 m2 plot. The dense canopy works as protection for other life-forms though; Lewandowski et al. notes that «[…] Miscanthus stands are usually reported to support farm biodiversity, providing habitat for birds, insects, and small mammals […].»[119] Both Haughton et al.[120] and Bellamy et al. found that the Miscanthus overwinter vegetative structure provided an important cover and habitat resource, with high levels of diversity in comparison with competing energy grasses. This effect was particularly evident for beetles, flies, and birds, with breeding skylarks and lapwings being recorded in the crop itself. The Miscanthus crop offers a different ecological niche for each season – the authors attribute this to the continually evolving structural heterogeneity of a Miscanthus crop, with different species finding shelter at different times during its development – woodland birds found shelter in the winter and farmland birds in the summer. For birds, 0.92 breeding pairs species per hectare (0.37 per acre) was found in the Miscanthus field, compared to 0.28 (0.11) in the wheat field. The authors note that due to the high carbon to nitrogen ratio it is in the field's margins and interspersed woodlands that the majority of the food resoures are to be found. Miscanthus fields work as barriers against chemical leaching into these key habitats however.[121]

Water quality[edit]

McCalmont et al. claims Miscanthus fields leads to significantly improved water quality because of significantly less nitrate leaching.[122] Likewise, Whitaker et al. claims that there is drastically reduced nitrate leaching from Miscanthus fields compared to the typical maize/soy rotation because of low or zero fertilizer requirements, the continuous presence of a plant root sink for nitrogen, and the efficient internal recycling of nutrients by perennial grass species. For instance, a recent meta-study concluded that Miscanthus had nine times less subsurface loss of nitrate compared to maize or maize grown in rotation with soya bean.[123]

Soil quality[edit]

The fibrous, extensive Miscanthus rooting system and the lack of tillage disturbance improves infiltration, hydraulic conductivity and water storage compared to annual row crops, and results in the porous and low bulk density soil typical under perennial grasses, with water holding capabilities expected to increase by 100-150 mm.[124] Nsanganwimana et al. argues that Miscanthus improves carbon input to the soil, and promote microorganism activity and diversity, which are important for soil particle aggregation and rehabilitation processes. On a former fly ash deposit site, with alkaline pH, nutrient deficiency, and little water-holding capacity, a Miscanthus x giganteus crop was sucessfully established – in the sense that the roots and rhizomes grew quite well, supporting and enhancing nitrification processes, although the above-ground dry weight yield was low because of the conditions. The authors argue that Miscanthus' ability to improve soil quality, even on contaminated land, can be used in combination with organic amendments on soils with a low agronomic value. For instance, there is a great potential to increase yield on contaminated marginal land low in nutrients by fertilizing it with nutrient-rich sewage sludge or wastewater. The authors claim that this practice offer the three-fold advantage of improving soil productivity, increasing biomass yields, and reducing costs for treatment and disposal of sewage sludge in line with the specific legislation in each country.[125]

Invasiveness[edit]

Miscanthus x giganteus' parents on both sides, M. sinensis and M. sacchariflorus, are both potentially invasive species, because they both produce viable seeds. M. x giganteus does not produce viable seeds however, and Nsanganwimana et al. claims that «[…] there has been no report on the threat of invasion due to rhizome growth extension from long-term commercial plantations to neighboring arable land.»[126]

Conclusion[edit]

There seem to be agreement in the scientific community that a shift from annual to perennial crops have environmental benefits. For instance, Lewandowski et al. conclude that analyses «[…] of the environmental impacts of miscanthus cultivation on a range of factors, including greenhouse gas mitigation, show that the benefits outweigh the costs in most cases.»[127] McCalmont et al. argues that although there is room for more research, «[…] clear indications of environmental sustainability do emerge.»[128] In addition to the GHG mitigation potential, Miscanthus' «[…] perennial nature and belowground biomass improves soil structure, increases water-holding capacity (up by 100–150 mm), and reduces run-off and erosion. Overwinter ripening increases landscape structural resources for wildlife. Reduced management intensity promotes earthworm diversity and abundance although poor litter palatability may reduce individual biomass. Chemical leaching into field boundaries is lower than comparable agriculture, improving soil and water habitat quality.»[129] Milner et al. argues that a change from first generation to second generation energy crops like Miscanthus is environmentally beneficial because of improved farm-scale biodiversity, predation and a net positive GHG mitigation effect. The benefits are primarily a consequence of low inputs and the longer management cycles associated with second generation (2G) crops.[130] The authors identifies 293247 hectares of arable land and grassland in the UK (equivalent to 1.3% of the total land area) where both the economical and environmental consequences of planting Miscanthus is seen as positive.[131] Whitaker et al. argues that if land use tensions are mitigated, reasonable yields obtained, and low carbon soils targeted, there are many cases where low-input perennial crops like Miscanthus «[…] can provide significant GHG savings compared to fossil fuel alternatives […].»[132] In contrast to annual crops, Miscanthus have low nitrogen input requirements, low GHG emissions, sequesters soil carbon due to reduced tillage, and can be economically viable on marginal land.[133] The authors agree that in recent years, «[…] a more nuanced understanding of the environmental benefits and risks of bioenergy has emerged, and it has become clear that perennial bioenergy crops have far greater potential to deliver significant GHG savings than the conventional crops currently being grown for biofuel production around the world (e.g. corn, palm oil and oilseed rape).»[134] The authors conclude that «[…] the direct impacts of dedicated perennial bioenergy crops on soil carbon and N2O are increasingly well understood, and are often consistent with significant lifecycle GHG mitigation from bioenergy relative to conventional energy sources.»[135]


Practical farming considerations[edit]

The farming considerations listed here are pulled from Emily Heaton and Danielle Wilson's 2013 fact sheet about Miscanthus establishment,[136] with some added numbers establishing compatibility with the metric system.

Tilling[edit]

A giant Miscanthus stand first begins with field seedbed preparation. To provide good soil to rhizome contact, the seedbed should be tilled to a 3–5-inch (8–13 cm) depth. Soil moisture is critical to proper establishment for early stage germination. If working with dry land, prepare your field just prior to planting for optimal soil moisture. Good soil contact is critical, so conversely, don’t till when the land is wet and clods will form. Nutrient (NPK) and lime applications should be made to the field as necessary before planting, following typical corn recommendations for the area. The plant’s efficient use of nitrogen implies that, once established, the crop will usually not require additional nitrogen input.

Planting[edit]

Vegetative propagation methods are necessary since giant Miscanthus does not produce viable seed. Currently, we only recommend spring planting of giant Miscanthus in the upper Midwest, and it should be timed similar to corn planting. When soil temperatures have reached 50 °F (10 °C) and probability of a spring frost is low, it is time to plant. Though Miscanthus can be planted as late as June, late planting leaves less time for the plant to develop a strong rhizome system to see it through the winter. Do not plant after July 1 without irrigation.

At this time (2013), there are two plant material options for starting a giant Miscanthus stand: rhizomes and small plants, commonly called ‘plugs.’

Rhizomes are overwinter storage organs that can also be used to grow new plants, similar to potatoes. Traditionally, new giant Miscanthus fields have been propagated by digging rhizome segments from ‘mother fields,’ a labor intensive process best done on sandy soils with specialized equipment. Rhizomes can be harvested from a dormant field of giant Miscanthus, typically any time after the first frost in the fall and before the last one in the spring. If not immediately replanted in a new field, they should be kept moist and cool (37–40 °F [3–4 °C]) in storage. Ideal rhizomes have two to three visible buds, are light colored, and firm (Fig. 1). Smaller rhizomes or those that are soft to the touch will likely have lower emergence.

Specialized rhizome planters are becoming available in the United States, and are based on potato planting technology. Typical planting rates are around 5–15 acres per day (2–6 hectares per day), though they can be much higher in ideal conditions. Because rhizomes are not all the same, planting depth can vary. It doesn’t matter what direction the rhizome faces, but it needs to be covered by 2 inches (5 cm) of soil. It is important that the rhizome is not sticking out of the ground, or it will quickly dry out. Rhizomes should be planted at a rate sufficient to achieve about 6000 plants per acre (15000 plants per hectare). It is difficult to know how many rhizomes this requires, since rhizomes are usually planted by weight, not by number. It is important to work with a rhizome supplier and planter that can help you calibrate the planter to achieve recommended populations. In Iowa, it is reasonable to expect 20-30 percent of rhizomes will either not grow, or die in the first year, so overplant accordingly.

Alternatively, vegetative propagation can be used to generate new giant Miscanthus fields in the greenhouse from stem or rhizome cuttings (Fig. 2). This allows the use of smaller plant pieces that can be divided more often, generating more plants in a given period of time than traditional rhizome production. This method is more expensive, but generates a uniform plant similar to what you might buy in a ‘six-pack’ container from a garden center (approximately 2 in × 2 in [5 cm × 5 cm] root ball). These small plants can be planted directly into the field with existing transplanting equipment like what is used in the vegetable or tobacco industry. As with rhizomes, typical planting rates are around 5–15 acres per day (2–6 hectares per day), though they can be much higher in ideal conditions. Depending on rainfall, you can expect about 20-30 percent of small plants to die within two months of planting, so plant extra to achieve target populations of 6,000 plants per acre (15,000 plants per hectare).

As mentioned earlier, target populations for giant Miscanthus are about 6,000 plants per acre (15,000 plants per hectare), and about 20-30 percent of plugs and rhizomes either die or don’t emerge, so overplant accordingly. Target plant spacing is 30 inches (76 cm) between plants both within and between rows (30-inch grid). Following planting, ensure the soil has been packed around the plug or over the rhizome to provide good soil contact, by either having a press-wheel behind the planter (plugs) or rolling the field after planting (rhizome).

Management[edit]

Management during the establishment year is critical to the survival of the giant Miscanthus stand. This is an expensive crop to establish, but done right, it should be productive with minimal inputs for the next 30 years, so take care of it the first year! Management during the establishment year involves:

Adequate water supply. This may be in Mother Nature’s hands, but if it is possible to irrigate the crop during dry periods after planting, then do it. Rhizomes are a bit more tolerant of moisture stress, but small plants need water after planting to settle the soil around the roots. Most transplanting equipment includes a water tank to give the plant a few cups at planting.

Weed management. Weed control is essential in the establishment year. Apply a pre-emergent herbicide at planting, and then control broadleaves as needed during the summer. Grass herbicides will not be safe on giant Miscanthus. Cultivation can also be effective, but take care not to damage emerging Miscanthus shoots. In 2013, only a few herbicides are labeled for giant Miscanthus. Harness® (Monsanto Co., acetochlor), Harness Xtra® (Monsanto Co., acetochlor + atrazine), Bicep® (Syngenta Co., metolachlor + atrazine), and 2,4-D can all be safely and legally used. Prowl® (BASF Corp., pendimethalin) products also worked well in research trials. Check with your local officials to understand herbicide restrictions in your area.

Nutrient needs. As described under ‘Field Preparation,’ nutrients should be brought up to corn thresholds prior to planting. No additional fertilizer is necessary during the establishment year.

Harvest. Don’t harvest the first year of growth! Establishing Miscanthus does best when the first year’s growth is left on the field over winter. If desired, you can mow or burn it in late spring the following year. Harvesting or burning prior to the first winter has been related to heavy plant losses in some environments. Mechanical, inter-row cultivation can be used for weed control during the early part of the first growing season.

Minimal inputs are needed following establishment. If weed pressure is heavy as the crop emerges in the second year, an herbicide application might be beneficial. As the stand matures, it will quickly outcompete weeds and an application should not be necessary in subsequent years.


External links[edit]

  • Aloterra Supplier and producer of Miscanthus based products (packaging, absorbents, pulp, nano-crystals).
  • Andritz Supplier of biomass technologies/factories.
  • C.F. Nielsen Biomass briquette machinery provider.
  • CPM Europe Biomass pellet machinery provider.
  • Energo Agrar LLC Provider of rhizomes and Miscanthus bales, chips and pellets. Also consulting.
  • GRACE EU research program for large-scale Miscanthus production on marginal land.
  • Kahl Biomass pellet machinery provider.
  • Maple River Farms Provider of Miscanthus rhizomes and bales.
  • NextFuel AB Provider of Miscanthus torrefaction technology. Licencing of the technology to third parties.
  • Miscanthus Nursery Limited UK Miscanthus farmer cooperative.
  • New Energy Farms Technology for the commercialization of perennial energy grasses.
  • NovaBiom Provider of rhizomes and Miscanthus chips/products.
  • Polytechnik Biomass processing technology provider.
  • SERC Sustainable Energy Research Center at Mississippi State University.
  • Sieverdingbeck Provider of Miscanthus rhizomes, chips and pellets.
  • Terravesta Miscanthus seed breeding research program ("MUST", in cooperation with Aberystwyth University), new Miscanthus planter, provider of Miscanthus rhizomes, BBQ briquettes, firestarters, and logs.
  • University of Illinois Institution for research on Miscanthus.


References[edit]

  1. ^ "Recent classification work at the Royal Botanic Gardens at Kew, England has designated it as M. x giganteus […] a hybrid of M. sinensis […] and M. sacchariflorus […] ." Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 71. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  2. ^ «M. x giganteus is a highly productive, sterile, rhizomatous C4 perennial grass that was collected in Yokahama, Japan in 1935 by Aksel Olsen. It was taken to Denmark where it was cultivated and spread throughout Europe and into North America for planting in horticultural settings.» Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 71. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  3. ^ «In contrast to annual crops, bioenergy from dedicated perennial crops is widely perceived to have lower life‐cycle GHG emissions and other environmental cobenefits (Rowe et al., 2009; Creutzig et al., 2015). Perennial crops such as Miscanthus and short‐rotation coppice (SRC) willow and poplar have low nitrogen input requirements (with benefits for N2O emissions and water quality), can sequester soil carbon due to reduced tillage and increased belowground biomass allocation, and can be economically viable on marginal and degraded land, thus minimizing competition with other agricultural activities and avoiding iLUC effects (Hudiburg et al., 2015; Carvalho et al., 2017).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  4. ^ «Ideal biomass energy crops efficiently use available resources, are perennial, store carbon in the soil, have high water-use efficiency, are not invasive and have low fertilizer requirements [1]. One grass that possesses all of these characteristics, as well as producing large amounts of biomass, is Miscanthus x giganteus [2].» Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 71. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  5. ^ Lewandowski et. al argues that the «[...] fossil-energy savings are highest where miscanthus biomass is used as construction material (our analysis uses the example of insulation material).» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  6. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 125. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  7. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 125. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  8. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 125. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  9. ^ «Producing rhizomes for propagation in the United Kingdom climate takes at least two growing season, this entails clearing the production ground of weeds, plowing in spring and tilling the ground to a fine seed bed like tilth before planting the rhizomes with a potato type planter. […] In the spring following the second growth year, the rhizomes are harvested using a modified potato harvester, hand or semi-automatically sorted and cut into viable pieces, 20–40 g. […] One ha of rhizomes produces enough material to plant 10–30 ha of crop with the same modified potato type planter. Lower quality rhizomes, tested by sprouting tests, would require 80–90 g rhizomes (private communication, M. Mos).» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017). Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  10. ^ «Our work is showing, depending on the hybrid type, one ha (hectare) of seed production can produce enough seed for ∼1000–2000 ha of planting, depending on parental combinations, two orders of magnitude greater than rhizome propagation. […] Trials with direct drilled Miscanthus seed trials are ongoing in the United Kingdom with an adapted Agricola Italiana precision pneumatic seed drill [35010 Massanzago, (PD), Italy] and have been shown to be a viable option of propagation. […] Technology for the plug production from seeds has been developed by Bell Brothers Nurseries Ltd. (United Kingdom), employing techniques used in the horticulture of vegetables and in field establishment agronomy using plug planters and film developed by IBERS/Terravesta Ltd. (United Kingdom) so that an 85–95% establishment rate is achieved.» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  11. ^ «Seeds are sown by machine and raised in the greenhouse (Figure 3A) before being planted out in the field (Figure 3B). It is anticipated that seed-based establishment methods will prove most effective for the scaling up of miscanthus production because they have the following advantages: - With increasing market demand, large quantities can easily be provided, once seed production has been well developed - Short growing period for plantlets: Only 8–10 weeks from seed to final product (plugs) - Plug production is energy efficient (no need for refrigerators) - Low establishment costs» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  12. ^ «Results show that new hybrid seed propagation significantly reduces establishment cost to below £900 ha-1[…]. The breakeven yield was calculated to be 6 Mg [megagram = metric ton] DM [dry matter] ha-1 y-1 [hectare per year], which is about half average United Kingdom yield for Mxg; with newer seeded hybrids reaching 16 Mg DM ha-1 in second year United Kingdom trials. These combined improvements will significantly increase crop profitability. The trade-offs between costs of production for the preparation of different feedstock formats show that bales are the best option for direct firing with the lowest transport costs (£0.04 Mg-1 km-1) and easy on-farm storage. However, if pelleted fuel is required then chip harvesting is more economic. We show how current seed based propagation methods can increase the rate at which Miscanthus can be scaled up; ∼×100 those of current rhizome propagation. These rapid ramp rates for biomass production are required to deliver a scalable and economic Miscanthus biomass fuel whose GHG emissions are ∼1/20th those of natural gas per unit of heat. […] The main establishment cost variable is the type of material planted as shown in Figure 2. In vitro is the most expensive followed by rhizome, seed and plug and the lowest is direct seed drilling. The specific cost of rhizome and plug planting are similar as they are relatively labor intensive whereas seed drilling, is predicted to halve the cost. The overall cost of plug propagation is 2/3 that of rhizome due mainly due to the higher multiplication factor of ∼2,000 to 1 compared to rhizome of 10–30 to 1. Direct seed drilling halves the cost of Miscanthus establishment (compared to rhizomes) to below £900 as well an increasing the ability to ramp up planted acreage. Even greater ramp ups can also be achieved by seed-plug propagation because less seed is wasted.» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  13. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 130. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  14. ^ «Early season herbicide application for weed control is essential in the establishing years but becomes redundant as the crop matures, other pesticides are not needed.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 503. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  15. ^ «C4 species characteristically demonstrate improved efficiency in nitrogen (N) and water-use [28,29]. Specifically, C4 species can show N-use efficiencies twice those of C3 species.» Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 73. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  16. ^ «Nitrogen fertilizer is unnecessary and can be detrimental to sustainability, unless planted into low fertility soils where early establishment will benefit from additions of around 50 kg N ha-1.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 503. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  17. ^ «N2O emissions can be five times lower under unfertilized Miscanthus than annual crops, and up to 100 times lower than intensive pasture land. Inappropriate nitrogen fertilizer additions can result in significant increases in N2O emission from Miscanthus plantations, exceeding IPCC emission factors although these are still offset by potential fossil fuel replacement.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 503. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  18. ^ John O'Loughlin, John Finnan, Kevin McDonnell: Accelerating early growth in miscanthus with the application of plastic mulch film. Biomass and Bioenergy, Volume 100, 2017, Pages 52-61. https://doi.org/10.1016/j.biombioe.2017.03.003
  19. ^ «Plastic mulch film reduced establishment time, improving crop economics. […] The mulch film trial in Aberystwyth showed a significant (P < 0.05) difference between establishment rates for varying plant densities with the cumulative first 2-year mean yield almost doubling under film as shown in Table 3. Using film adds £100 per ha and 220 kg CO2 eq. C ha-1, to the cost of establishment. The effect of this increase is to reduce the establishment period of the crop by 1 year in Aberystwyth environmental conditions, similar reduction in establishment times were observed at the other trial sites and also in Ireland (O’Loughlin et al., 2017). […] With mulch film agronomy the latest seeded hybrids establish far more quickly with significantly higher early yields (years 1 and 2) compared to commercial Mxg in the United Kingdom delivering a breakeven return on investment at least a year earlier.» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  20. ^ «The planting of seed-derived plugs proved to be most successful method for miscanthus establishment on marginal soils. Covering the plants with a plastic film accelerates their growth. The film keeps the humidity in the topsoil and increases the temperature. This is beneficial for the plants, especially on light soils with a higher risk for drought stress and in cool temperatures.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  21. ^ «Crop productivity is determined as the product of total solar radiation incident on an area of land, and the efficiencies of interception, conversion and partitioning of that sunlight energy into plant biomass [34]. […] Efficiency of light interception (εi) is largely dependent on canopy architecture, leaf-area index [35] and duration of the growing season [36,37]. M. x giganteus achieved an εi of 0.80 under midwestern US conditions, or 0.51–0.55 when calculated over the entire year [38]. At the same site, small plot trials achieved an εi of 0.72 [2], while trials in Europe achieved an εi of 0.32–0.83 when calculated over the growing season [36]. Heaton et al. obtained conversion efficiencies of photosynthetically active radiation (PAR) to above-ground material (εc,a) of 0.075 in the midwestern USA [2], while studies by Dohleman and Long [37] and Dohleman et al. observed an εc,a of 0.039–0.045 on large plot trials [38]. Beale and Long demonstrated in field trials in southeastern England that εc,a was 0.050–0.060, 39% above the maximum value observed in C3 species [36]. Furthermore, when εc is calculated in terms of total (i.e., above-ground and below-ground) M. x giganteus biomass production (εc,t), it reaches 0.078 [36], which approaches theoretical maximum of 0.1. Studies performed in the midwestern USA by Heaton et al. reported a similar efficiency of intercepted PAR (0.075) [2]. Finally, early closure of the M. x giganteus canopy and an extended growing season allow for increased incident PAR [36,37] and, therefore, increased overall productivity.» Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 73. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  22. ^ «Water‐use efficiency is among the highest of any crop, in the range of 7.8–9.2 g DM (kg H2O)−1. - Overall, water demand will increase due to high biomass productivity and increased evapotranspiration at the canopy level (e.g. ET up from wheat by 100–120 mm yr−1). - Improved soil structures mean greater water‐holding capacity (e.g. up by 100–150 mm), although soils may still be drier in drought years. - Reduced run‐off in wetter years, aiding flood mitigation and reducing soil erosion. - Drainage water quality is improved, and nitrate leaching is significantly lower than arable (e.g. 1.5–6.6 kg N ha−1 yr−1 [for] Miscanthus, 34.2–45.9 [for] maize/soya bean).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 504. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  23. ^ «Miscanthus has higher water‐use efficiency (WUE) compared to more conventional C3 crop species, and even some other C4 crops which typically produce more biomass per unit of water transpired (Long, 1983). Beale et al. (1999) investigated WUE in field trials of Miscanthus and another potential C4 biomass crop, Spartina cynosuroides, under both rain‐fed and irrigated conditions; they estimated the ratio of aboveground biomass to water use for Miscanthus under rain‐fed conditions at 9.2 g DM (kg H2O)−1 compared to 6.8 g DM (kg H2O)−1 for S. cynosuroides. Both crops appeared to become less efficient under irrigation, down by 15% for Miscanthus to 7.8 g DM (kg H2O)−1 and 25% for S. cynosuroides to 5.1 g DM (kg H2O)−1, possibly reflecting greater canopy evaporation under the irrigation regime. Beale et al. (1999) compared their results to the water‐use efficiency of a C3 biomass crop, Salix viminalis, reported in Lindroth et al. (1994) and Lindroth & Cienciala (1996), and suggest that WUE for Miscanthus could be around twice that of this willow species. Clifton‐Brown & Lewondowski (2000) reported figures from 11.5 to 14.2 g total (above‐ and belowground) DM (kg H2O)−1 for various Miscanthus genotypes in pot trials, and this compares to figures calculated by Ehdaie & Waines (1993) with seven wheat cultivars who found WUE between 2.67 and 3.95 g total DM (kg H2O)−1. Converting these Miscanthus values to dry matter biomass per hectare of cropland would see ratios of biomass to water use in the range of to 78–92 kg DM ha−1 (mm H2O)−1. Richter et al. (2008) modelled harvestable yield potentials for Miscanthus from 14 UK field trials and found soil water available to plants was the most significant factor in yield prediction, and they calculated a DM yield to soil available water ratio at 55 kg DM ha−1 (mm H2O)−1, while just 13 kg DM ha−1 was produced for each 1 mm of incoming precipitation, likely related to the high level of canopy interception and evaporation. Even by C4 standards these efficiencies are high, as seen in comparisons to field measurements averaging 27.5 ± 0.4 kg aboveground DM ha−1 (mm H2O)−1 for maize (Tolk et al., 1998). (Vanloocke et al., 2010).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 501. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  24. ^ «In terms of energy production intensity, Miscanthus biomass produces more net energy per hectare than other bioenergy crops at around 200 GJ ha−1 yr−1, especially arable [maize for biogas 98, oil seed rape for biodiesel 25, wheat and sugar beet ethanol 7–15 (Hastings et al., 2012)]. Felten et al. (2013) calculated similar figures, reporting 254 GJ ha−1 yr−1 for Miscanthus. Energy production intensity calculated for woody perennials can vary significantly by area (Bauen et al., 2010) with yield predictions largely driven by future climate projections (Hastings et al., 2013).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 493. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  25. ^ «The majority of the literature reporting dry biomass yield for M. x giganteus originates from European studies. Ceiling peak biomass yields in established stands of M. x giganteus have approached 40 t dry matter (DM) ha-1 in some European locations, although it may take 3–5 years to achieve these ceiling yields [84]. Across Europe, harvestable yields of up to 25 t DM ha-1 from established stands of M. x giganteus have been reported in areas between central Germany and southern Italy, while peak yields in central and northern Europe have ranged between 10–25 t DM ha-1, and in excess of 30 t DM ha-1 in southern Europe [3]. A quantitative review of established M. x giganteus stands across Europe reported a mean peak biomass yield of 22 t DM ha-1, averaged across N rates and precipitation levels [1].» Eric Anderson, Rebecca Arundale, Matthew Maughan, Adebosola Oladeinde, Andrew Wycislo & Thomas Voigt (2011) Growth and agronomy of Miscanthus x giganteus for biomass production, Biofuels, 2:1, page 79. https://doi.org/10.4155/bfs.10.80  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  26. ^ Clifton-Brown, J.C., P.F. Stampfl and M.B. Jones. 2004. Miscanthus biomass production for energy in europe and its potential contribution to decreasing fossil fuel carbon emissions. Global Change Biology 10, no 4: 509–18. https://doi.org/10.1111/j.1529-8817.2003.00749.x
  27. ^ Emily Heaton. "Factsheet | Biomass: Miscanthus." Accessed December 12, 2018. http://s3-us-west-2.amazonaws.com/grainnet-com/uploads/company-logos/Miscanthus-Fact-Sheet.pdf.
  28. ^ Felten, D., & Emmerling, C. (2012). Accumulation of Miscanthus-derived carbon in soils in relation to soil depth and duration of land use under commercial farming conditions. Journal of Plant Nutrition and Soil Science, 175(5), page 662. https://doi.org/10.1002/jpln.201100250
  29. ^ McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 497. https://doi.org/10.1111/gcbb.12294
  30. ^ «The yields used in the calculation of GHG emissions and crop economics this study used mean yields of 12–14 Mg ha-1 y-1 that have been observed from Mxg from current commercial plantings observed in the United Kingdom (private communication, M. Mos). We have assumed a logistic yield increase for establishment year yields and a linear decline in yield after 15 years Lesur et al. (2013). Inter-annual yield variation, due to weather conditions, as observed in long term trials (Clifton-Brown et al., 2007) and modeled Miscanthus yields for the United Kingdom, using weather data from 2000 to 2009 (Harris et al., 2014) using the MiscanFor model (Hastings et al., 2009, 2013) indicates that the weather related standard deviation of inter-annual yield variation in the United Kingdom is of the order 2.1 Mg ha-1 y-1 for a mean yield of 10.5 Mg ha-1 y-1 for the whole of the United Kingdom. The modeled yields are generally pessimistic as they calculate rain-fed yields and do not account for ground water support that is available in many United Kingdom arable farms.» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058 http://s3-us-west-2.amazonaws.com/grainnet-com/uploads/company-logos/Miscanthus-Fact-Sheet.pdf
  31. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 125. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  32. ^ «The Asia-Pacific Economic Cooperation (APEC) estimates that marginal lands make up approximately 400 million hectares across Asia, the Pacific Islands, Australia, and North America [4]. Other estimates put the global marginal land area anywhere from 1100 [5] to 6650 million hectares [2], depending on the parameters used to describe marginal (e.g., “non-favored agricultural land,” “abandoned or degraded cropland,” or arid, forested, grassland, shrubland, or savanna habitats). The potential area available in the USA for cellulosic biomass crops and low-input, high-diversity native perennial mixtures ranges from 43 to 123 million hectares [5, 6]. The differences in these estimates reflect the inconsistencies in the usage of the term “marginal land,” despite its common use in the bioenergy industry and literature [5, 7, 8]. Marginal lands are often described as degraded lands that are unfit for food production and/or of some ambiguously poor quality and are often termed unproductive [7]. Unproductive soils are characterized by unfavorable chemical and/or physical properties that limit plant growth and yield, including low water and nutrient storage capacity, high salinity, toxic elements, and poor texture [4, 9]. Further difficulties encountered in marginal landscapes include shallow soil depth due to erosion, poor drainage, low fertility, steep terrain, and unfavorable climate [2]. Despite the poor quality of marginal land and the potential problems it could present for its production, biomass is unlikely to be grown on high-quality land that is economically viable for traditional crops [7].» Quinn, L.D., Straker, K.C., Guo, J. et al. Stress-Tolerant Feedstocks for Sustainable Bioenergy Production on Marginal Land. BioEnergy Research (2015) 8: 1081. https://doi.org/10.1007/s12155-014-9557-y  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  33. ^ «Our literature review has revealed several “all purpose” biomass crops that are moderately or highly tolerant of multiple environmental stressors (Table 6). For example, Andropogon gerardii, Eucalyptus spp., Miscanthus spp., Panicum virgatum, Pinus spp., Populus spp., Robinia pseudoacacia, and Spartina pectinata were shown to be moderately or highly tolerant of four or more stress types.[…] Miscanthus × giganteus leaf area and yield reduced under drought stress [59], but water availability does not affect shoot production or plant height at the beginning of the growing season [60].[…]Miscanthus × giganteus biomass and rhizome viability unaffected by flooding [52].[…] Salinity above 100 mM affected Miscanthus × giganteus growth, with rhizomes > roots > shoots in order of increasing sensitivity (rhizomes least sensitive).[…] The lethal temperature at which 50 % (LT50) of Miscanthus × giganteus rhizomes were killed was −3.4 °C, which can be problematic especially during first winter. In Miscanthus sinensis, LT50 was −6.5 °C [220]. Miscanthus × giganteus shows unusual cold tolerance for a C4 species [60]. Miscanthus sinensis grows where Tmin is down to −11 °C [221]. […] C4 and CAM species have inherent mechanisms to resist heat stress […] Heat shock genes have been identified in Miscanthus sinensis and could be used to improve future hybrids [248].» Quinn, L.D., Straker, K.C., Guo, J. et al. Stress-Tolerant Feedstocks for Sustainable Bioenergy Production on Marginal Land. BioEnergy Research (2015) 8: 1081. https://doi.org/10.1007/s12155-014-9557-y  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  34. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 124. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  35. ^ «Most saline soils covering 539 567 km2 in the European geographical area can be used to grow Miscanthus with up to an estimated 11% reduction in yield; a further 2717 km2 can be used with an estimated 28% reduction in yield, and only, 3607 km2 will produce a yield reduction greater that 50%.» Stavridou, E. , Hastings, A. , Webster, R. J. and Robson, P. R. (2017), The impact of soil salinity on the yield, composition and physiology of the bioenergy grass Miscanthus × giganteus. GCB Bioenergy, 9: 92-104. https://doi.org/10.1111/gcbb.12351  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  36. ^ «Rhizome D.W. [dry weight] and the ratios of root/rhizome and below‐/above‐ground D.W. were not affected by increased salinity, and only, the root D.W. was significantly reduced at the highest salt concentration (22.4 dS m−1 NaCl) (Table 1). Płażek et al. (2014) showed a similar response in M. × giganteus, with reduction only in roots D.W. at 200 mm NaCl and no changes in rhizomes D.W. below 200 mm NaCl. This ability of perennial grasses to maintain below‐ground biomass under stress conditions could preserve sufficient reserves for the following growing season (Karp & Shield, 2008); while this may be physiologically relevant for transitory stresses like drought, it remains to be seen how this response affects year on year yield under the accumulative stress effect of salinity.» Stavridou, E. , Hastings, A. , Webster, R. J. and Robson, P. R. (2017), The impact of soil salinity on the yield, composition and physiology of the bioenergy grass Miscanthus × giganteus. GCB Bioenergy, 9: 92-104. https://doi.org/10.1111/gcbb.12351  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  37. ^ «The highest biomass yields as well as the highest GHG- and fossil-energy savings potentials (up to 30.6 t CO2eq/ha*a [CO2 equivalents per hectare per year] and 429 GJ/ha*a [gigajoule per hectare per year], respectively) can be achieved on non-marginal sites in Central Europe. On marginal sites limited by cold (Moscow/Russia) or drought (Adana/Turkey) savings of up to 19.2 t CO2eq/ha*a and 273 GJ/ha*a (Moscow) and 24.0 t CO2eq/ha*a and 338 GJ/ha*a (Adana) can be achieved.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  38. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 126. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  39. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 128. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  40. ^ «Miscanthus grown on contaminated soils can contain higher shoot TE [trace elements; metals and metalloids] concentrations, but the TF [translocation factor], which is for the most part less than 1, indicates that root-to-shoot TE transfer is minimized (Table 3). The combination of this trait with low BCF [bio concentration factor] and higher TE concentrations in roots than in shoots demonstrates the capacity to contain TE in soils. Owing to the perennial growth and its ability to stabilize TE and degrade some organic pollutants, Miscanthus could potentially limit pollutant transfer into different environmental compartments by reducing (1) pollutant leaching from the root zone and groundwater contamination, (2) pollutant run-off (water erosion) and surface water contamination, (3) dust emission into the atmosphere due to wind erosion and seasonal soil tillage, and (4) pollutant transfer into plant AG [above ground] parts and thus transfer into food chains. Therefore, as non-food crops, Miscanthus forms a potential resource for phytomanagement of contaminated areas, with the option of TE phytostabilization and/or organic pollutant degradation, hence the opportunity to reduce both human and environmental risks.» Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 129. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  41. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 129. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  42. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 131. https://doi.org/10.1016/j.jenvman.2014.04.027 PDF: http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  43. ^ «With careful attention to agronomy during establishment, Miscanthus (mainly M × g) has proven to be productive on lower grade agricultural land, including heavy metal contaminated (Nsanganwimana et al., 2014; Pidlisnyuk et al., 2014) and saline soils (Sun et al., 2014; Stavridou et al., 2016). Miscanthus can therefore contribute to the sustainable intensification of agriculture, allowing farmers to diversify and provide biomass for an expanding market without compromising food security.» Clifton‐Brown, J. , Hastings, A. , Mos, M. , McCalmont, J. P., Ashman, C. , Awty‐Carroll, D. , Cerazy, J. , Chiang, Y. , Cosentino, S. , Cracroft‐Eley, W. , Scurlock, J. , Donnison, I. S., Glover, C. , Gołąb, I. , Greef, J. M., Gwyn, J. , Harding, G. , Hayes, C. , Helios, W. , Hsu, T. , Huang, L. S., Jeżowski, S. , Kim, D. , Kiesel, A. , Kotecki, A. , Krzyzak, J. , Lewandowski, I. , Lim, S. H., Liu, J. , Loosely, M. , Meyer, H. , Murphy‐Bokern, D. , Nelson, W. , Pogrzeba, M. , Robinson, G. , Robson, P. , Rogers, C. , Scalici, G. , Schuele, H. , Shafiei, R. , Shevchuk, O. , Schwarz, K. , Squance, M. , Swaller, T. , Thornton, J. , Truckses, T. , Botnari, V. , Vizir, I. , Wagner, M. , Warren, R. , Webster, R. , Yamada, T. , Youell, S. , Xi, Q. , Zong, J. and Flavell, R. (2017), Progress in upscaling Miscanthus biomass production for the European bio‐economy with seed‐based hybrids. GCB Bioenergy, 9: page 2. https://doi.org/10.1111/gcbb.12357  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  44. ^ Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: 317-333. https://doi.org/10.1111/gcbb.12263
  45. ^ «Soil carbon stocks are a balance between the soil organic matter decomposition rate and the organic material input each year by vegetation, animal manure, or any other organic input.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 496. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  46. ^ Clifton‐Brown, J. C., Breuer, J. and Jones, M. B. (2007), Carbon mitigation by the energy crop, Miscanthus. Global Change Biology, 13: page 2297. https://doi.org/10.1111/j.1365-2486.2007.01438.x
  47. ^ Dondini, M. , Hastings, A. , Saiz, G. , Jones, M. B. and Smith, P. (2009), The potential of Miscanthus to sequester carbon in soils: comparing field measurements in Carlow, Ireland to model predictions. GCB Bioenergy, 1: page 414, 419-420. https://doi.org/10.1111/j.1757-1707.2010.01033.x
  48. ^ Poeplau, C. and Don, A. (2014), Soil carbon changes under Miscanthus driven by C4 accumulation and C3 decompostion – toward a default sequestration function. GCB Bioenergy, 6: page 335. https://doi.org/10.1111/gcbb.12043
  49. ^ «SOC [soil organic carbon] derived from crop inputs will be lower during the early years of establishment (Zimmermann et al., 2012) with disturbance losses of resident C3 carbon outpacing C4 inputs when planted into grassland.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 496. https://doi.org/10.1111/gcbb.12294.  This article incorporates text available under the CC BY 4.0 license. The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original articles itself. More info: https://en.wikipedia.org/wiki/Creative_Commons_license
  50. ^ «Likewise, N2O (nitrous oxide) emissions vary strongly with prior land use, crop maturity, and fertilzation rate, however «[…] postestablishment emissions from perennial crops were generally much lower than emissions from annual crops […] we conclude that targeting low carbon soils for perennial bioenergy crop cultivation will reduce soil carbon losses in the short‐term and promote soil carbon sequestration in the long‐term. Globally, it is proposed that managing land to promote such sequestration, and avoid loss, may be a valuable tool in the mitigation of climate change (Lal, 2003).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original articles itself. More info: https://en.wikipedia.org/wiki/Creative_Commons_license
  51. ^ «Any soil disturbance, such as ploughing and cultivation, is likely to result in short-term respiration losses of soil organic carbon, decomposed by stimulated soil microbe populations (Cheng, 2009; Kuzyakov, 2010). Annual disturbance under arable cropping repeats this year after year resulting in reduced SOC levels. Perennial agricultural systems, such as grassland, have time to replace their infrequent disturbance losses which can result in higher steady-state soil carbon contents (Gelfand et al., 2011; Zenone et al., 2013).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 493. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  52. ^ Felten, D., & Emmerling, C. (2012). Accumulation of Miscanthus-derived carbon in soils in relation to soil depth and duration of land use under commercial farming conditions. Journal of Plant Nutrition and Soil Science, 175(5), page 661. https://doi.org/10.1002/jpln.201100250
  53. ^ Dondini et al. does not explicitely quantify above ground dry mass yield, instead the median of McCalmont's 10-15 tonnes estimation for the whole of the UK is used here (see above), together with a carbon content estimation of 48%. Dondini, M. , Hastings, A. , Saiz, G. , Jones, M. B. and Smith, P. (2009), The potential of Miscanthus to sequester carbon in soils: comparing field measurements in Carlow, Ireland to model predictions. GCB Bioenergy, 1, page 422. https://doi.org/10.1111/j.1757-1707.2010.01033.x For the carbon content estimation, see Petra Kahle, Steffen Beuch, Barbara Boelcke, Peter Leinweber, Hans-Rolf Schulten, Cropping of Miscanthus in Central Europe: biomass production and influence on nutrients and soil organic matter, European Journal of Agronomy, Volume 15, Issue 3, 2001, table 3, page 176. https://doi.org/10.1016/S1161-0301(01)00102-2
  54. ^ Given a mean UK dry mass yield of 12.5 tonnes per hectare (see McCalmont, above), and the standard 48% carbon content estimation (see Kahle et al. above.) Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: table 4, page 322. https://doi.org/10.1111/gcbb.12263
  55. ^ In general, low accumulation rates for young plantations are to be expected, because of tillage-induced aeration of the soil, and low input during the establishment phase. Total dry mass per hectare per year quoted as 25.6 (± 0.2) tonnes per hectare per year. Carbon content estimation 48% (see Kahle et al., above). Toru Nakajima, Toshihiko Yamada, Kossonou Guillaume Anzoua, Rin Kokubo & Kosuke Noborio (2018) Carbon sequestration and yield performances of Miscanthus × giganteus and Miscanthus sinensis, Carbon Management, 9:4, 415-423. https://doi.org/10.1080/17583004.2018.1518106
  56. ^ The 16 year Miscanthus site had 106 tonnes of below-ground carbon per hectare. Control site 1 had 91 tonnes of below-ground carbon, control site 2 had 92 tonnes. Mean difference to the control sites 15.5 tonnes. For above-ground carbon, the total harvested dry matter per hectare for the 16 year site was 114 tonnes, or 7.13 tonnes per year. After 16 years, the total belowground carbon derived from Miscanthus (C4) had reached 18 tonnes, equivalent to 29% of the total inputted Miscanthus carbon (coming from fallen leaves, rhizomes and roots). Miscanthus-derived carbon input per year was 1.13 tonnes. Hansen, Elly & Christensen, B.T. & Jensen, Lars & Kristensen, Kristian. (2004). Carbon sequestration in soil beneath long-term Miscanthus plantations as determined by 13C abundance. Biomass and Bioenergy. 26. page 102-103. https://doi.org/10.1016/S0961-9534(03)00102-8 PDF: https://eurekamag.com/pdf/004/004064611.pdf
  57. ^ «[…] it seems likely that arable land converted to Miscanthus will sequester soil carbon; of the 14 comparisons, 11 showed overall increases in SOC over their total sample depths with suggested accumulation rates ranging from 0.42 to 3.8 Mg C ha-1 yr-1. Only three arable comparisons showed lower SOC stocks under Miscanthus, and these suggested insignificant losses between 0.1 and 0.26 Mg ha-1 yr-1.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 493. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  58. ^ «The correlation between plantation age and SOC can be seen in Fig. 6, […] the trendline suggests a net accumulation rate of 1.84 Mg C ha-1 yr-1 with similar levels to grassland at equilibrium.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 496. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  59. ^ Given the EU average yield of 18.8 tonnes dry matter per hectare per year (see Clifton-Brown, above), and 48% carbon content (see Kahle et al,, above).
  60. ^ Bridgeman, T. G., Jones, J. M., Shield, I., & Williams, P. T. (2008). Torrefaction of reed canary grass, wheat straw and willow to enhance solid fuel qualities and combustion properties. Fuel, 87(6), page 845. https://doi.org/10.1016/j.fuel.2007.05.041
  61. ^ «Biomass production costs for miscanthus are presently too high to compete commercially with fossil fuels on an energy basis. The high biomass production costs for miscanthus result from insufficient development of agricultural production technology, accompanied by additional costs for agricultural inputs, land and labor for a relatively low-value biomass. Although they are amortized over a production period of 10–25 years, initial establishment costs for miscanthus are still comparatively high. This is because the only commercially available genotype Miscanthus × giganteus is a triploid hybrid that does not produce viable seeds. Consequently, costly establishment via rhizome or in vitro propagation has to be performed (Xue et al., 2015). Miscanthus is also new to farmers and they have neither the knowledge nor the technical equipment to cultivate it. Thus, inefficient production technology is currently limiting its widespread uptake as a biomass crop. There are no stable markets for miscanthus biomass and relevant applications are low-value. Farmers are hesitant to cultivate miscanthus because it involves dedicating their fields to long-term biomass production. They will only be willing to do this once biomass markets are stable or if long-term contracts are available (Wilson et al., 2014). The main use of lignocellulosic biomass from perennial crops is as a solid fuel for heat and power generation—a comparatively low-value use, its profitability being ultimately determined by the price of fossil fuels. In Europe, subsidies are generally necessary for bioenergy products to be able to compete in retail energy markets—with the notable exception of forest wood and forestry by-products that cannot be used for wood material products. Therefore, also higher-value applications for miscanthus biomass are required in order to provide attractive market options. There are no miscanthus varieties adapted to different site characteristics and biomass use options. In Europe, Miscanthus × giganteus is the only genotype commercially available. Major barriers to the breeding of miscanthus varieties are the high costs involved and the long breeding periods, necessary because most yield- and quality-relevant parameters are not quantifiable until after the establishment phase of 2–3 years.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  62. ^ Hyeon-Jong Jun*, Il-Su Choi, Tae-Gyoung Kang, Yong Choi, Duck-Kyu Choi, Choung-Keun Lee. Required Mowing Power and Bale Density of Miscanthus × Giganteus for Field Biomass Harvesting using Different Methods. Journal of Biosystems Engineering. 39(4): 253-260. (2014. 12) http://dx.doi.org/10.5307/JBE.2014.39.4.253
  63. ^ Spyros Kyritsis. 1st World Conference on Biomass for Energy and Industry: Proceedings of the Conference Held in Sevilla, Spain, 5-9 June 2000, Volum 1, page 2098.
  64. ^ Michael Wild: «Torrefied biomass: The perfect CO2 neutral coal substitute is maturing.» VGB PowerTech 7 2015. http://www.bioendev.se/wordpress/wp-content/uploads/2015/09/VGB-PowerTech-2015-07-072-075-WILD-Autorenexemplar1.pdf
  65. ^ "Torrefaction Benefits – IBTC".
  66. ^ Michael Wild, Lotte Visser: «Biomass pre-treatment for bioenergy. Case study 1: Biomass torrefaction.» IEA Bioenergy 2018, page 18. https://www.ieabioenergy.com/wp-content/uploads/2018/10/CS1-Torrefaction.pdf
  67. ^ Michael Wild, Lotte Visser: «Biomass pre-treatment for bioenergy. Case study 1: Biomass torrefaction.» IEA Bioenergy 2018, page 13. https://www.ieabioenergy.com/wp-content/uploads/2018/10/CS1-Torrefaction.pdf
  68. ^ Torrefied biomass has a moisture content of below 5%. The reason there is still some moisture in torrefied material in spite of its hydrophobic quality, is small cracks or fissures in the pellets or briquettes that makes it possible for water to enter. Michael Wild: «Torrefied biomass: The perfect CO2 neutral coal substitute is maturing.» VGB PowerTech 7 2015. http://www.bioendev.se/wordpress/wp-content/uploads/2015/09/VGB-PowerTech-2015-07-072-075-WILD-Autorenexemplar1.pdf
  69. ^ http://ibtc.bioenergyeurope.org/torrefaction-benefits/
  70. ^ "Torrefaction Benefits – IBTC".
  71. ^ Michael Wild: «Torrefied biomass: The perfect CO2 neutral coal substitute is maturing.» VGB PowerTech 7 2015. http://www.bioendev.se/wordpress/wp-content/uploads/2015/09/VGB-PowerTech-2015-07-072-075-WILD-Autorenexemplar1.pdf
  72. ^ Michael Wild: «Torrefied biomass: The perfect CO2 neutral coal substitute is maturing.» VGB PowerTech 7 2015. http://www.bioendev.se/wordpress/wp-content/uploads/2015/09/VGB-PowerTech-2015-07-072-075-WILD-Autorenexemplar1.pdf
  73. ^ Li, Yueh-Heng & Lin, Hsien-Tsung & Xiao, Kai-Lin & Lasek, Janusz, 2018. "Combustion behavior of coal pellets blended with Miscanthus biochar," Energy, Elsevier, vol. 163(C), page 181. https://doi.org/10.1016/j.energy.2018.08.117
  74. ^ T.G. Bridgeman, J.M. Jones, A. Williams, D.J. Waldron, An investigation of the grindability of two torrefied energy crops, Fuel, Volume 89, Issue 12, 2010, Page 3912, https://doi.org/10.1016/j.fuel.2010.06.043
  75. ^ «Flame stability can be further exacerbated by differences in particle size as large particle sizes can act as heat sinks, increasing the resonance time of the particle before ignition and influencing the balance of heat loss and heat release. For a stable flame in a pulverised coal operation, pulverisation of fuel to 70% below 75 µm is typically required. [It is required to reduce 70% of the total amount of particles to below 75 µm in size.] The ease in which fuels can be pulverised to 70% below 75 µm is described using the Hardgrove Grindability Index (HGI). Coals typically lie between 30 (increased resistance to pulverization) and 100 (more easily pulverised) on the scale. The HGI for the unprocessed Miscanthus and processed bio-coals are given in Table 3. The unprocessed Miscanthus has an HGI of zero which essentially implies under the test conditions, that no fuel would reach the desired 75 µm and thus, assuming co-milling, there would be either a greater energy requirement for milling to achieve 75 µm or the pulverised fuel particles would be greater than 75 µm in diameter.» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license) https://doi.org/10.1111/gcbb.12488
  76. ^ Ndibe, C., Grathwohl, S., Paneru, M., Maier, J., & Scheffknecht, G. (2015). Emissions reduction and deposits characteristics during cofiring of high shares of torrefied biomass in a 500 kW pulverized coal furnace. Fuel, 156, page 177. https://doi.org/10.1016/j.fuel.2015.04.017
  77. ^ T.G. Bridgeman, J.M. Jones, A. Williams, D.J. Waldron, An investigation of the grindability of two torrefied energy crops, Fuel, Volume 89, Issue 12, 2010, Page 3916, https://doi.org/10.1016/j.fuel.2010.06.043. Smith et al. measured a HGI of 150 for Miscanthus pre-treated with hydrothermal carbonisation: «The HGI of 150 (see Table 3) for the samples processed at 250 °C also imply that the fuel will easily pulverise and there should be limited issues with flame stability brought about though larger particle diameters encountered with untreated biomass.» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license) https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  78. ^ Marcel Cremers et al.: «Status overview of torrefaction technologies. A review of the commercialisation status of biomass torrefaction» IEA Bioenergy 2015. Task 32. https://www.ieabioenergy.com/wp-content/uploads/2015/11/IEA_Bioenergy_T32_Torrefaction_update_2015b.pdf page 11
  79. ^ «On average, coals used in UK power stations have a HGI around 40–60; the La Loma coal tested in this work falls within this range with a HGI of 46.» Orla Williams, Carol Eastwick, Sam Kingman, Donald Giddings, Stephen Lormor, Edward Lester, Investigation into the applicability of Bond Work Index (BWI) and Hardgrove Grindability Index (HGI) tests for several biomasses compared to Colombian La Loma coal, Fuel, Volume 158, 2015, Pages 379-387. https://doi.org/10.1016/j.fuel.2015.05.027  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  80. ^ Michael Wild, Lotte Visser: «Biomass pre-treatment for bioenergy. Case study 1: Biomass torrefaction.» IEA Bioenergy 2018, page 17. https://www.ieabioenergy.com/wp-content/uploads/2018/10/CS1-Torrefaction.pdf
  81. ^ Ndibe, C., Grathwohl, S., Paneru, M., Maier, J., & Scheffknecht, G. (2015). Emissions reduction and deposits characteristics during cofiring of high shares of torrefied biomass in a 500 kW pulverized coal furnace. Fuel, 156, page 189. https://doi.org/10.1016/j.fuel.2015.04.017
  82. ^ Ren, X., Sun, R., Chi, H.-H., Meng, X., Li, Y., & Levendis, Y. A. (2017). Hydrogen chloride emissions from combustion of raw and torrefied biomass. Fuel, 200, page 38. https://doi.org/10.1016/j.fuel.2017.03.040
  83. ^ Joakim M. Johansen, Jon G. Jakobsen, Flemming J. Frandsen, and Peter Glarborg. Release of K, Cl, and S during Pyrolysis and Combustion of High-Chlorine Biomass. Energy & Fuels 2011 25 (11), 4962, https://doi.org/10.1021/ef201098n
  84. ^ «Inorganics can be a particular issue for Miscanthus during combustion as large amounts of alkali and alkaline metals, particularly potassium and sodium, along with sulphur and chlorine influence ash chemistry and influence the behaviours of the fuel in terms of its tendency to corrode equipment and cause slagging, fouling and in certain furnaces bed agglomeration [39].» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, page 554, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  85. ^ «In the combustion of miscanthus, the inorganic constituents remain as ash. The typical total ash content of miscanthus is in the range of 2.0% to 3.5% [8,9,10]. In grate-fired combustion systems, the coarser ash is discharged as bottom ash while the finer ash fraction leaves the combustion zone with the off-gas as fly ash. Because of the low ash melting temperature, which is strongly correlated with the potassium and chloride content of the ash, the combustion temperature is kept as low as possible [11].» Lanzerstorfer, C. Combustion of Miscanthus: Composition of the Ash by Particle Size. Energies 2019, 12, 178. https://doi.org/10.3390/en12010178  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  86. ^ «Slagging is a phenomenon brought about though the melting of ash when ash deposits are exposed to radiant heat, such as flames in a furnace. As most furnaces are designed to remove ash as a powdery residue, having a high ash melting temperature is often desirable. Otherwise it has a higher tendency to fuse into a hard glassy slag, known as a clinker, which can be difficult to remove from the furnace [39].» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  87. ^ «The AFT is a qualitative method of assessing the propensity of a fuel to slag and works by heating an ash test piece and analysing the transitions in the ash chemistry. Key transitions include; (i) shrinkage, which predominantly represents the decomposition of carbonates in hydrothermally derived chars, (ii) deformation temperature, essentially representing the onset point at which the powdery ash starts to agglomerate and starts to stick to surfaces, (iii) hemisphere, whereby ash is agglomerating and is sticky and (v) flow, whereby the ash melts. For most power stations, slagging becomes problematic between the deformation and hemisphere temperature.» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  88. ^ «For Miscanthus to best fit the combustion quality requirements, it is conventionally harvested during the late winter or early spring in the UK, after which the crop has fully senesced and nutrients have been remobilised into the rhizome. […] Moreover while late harvested Miscanthus samples have improved fuel quality, with lower nitrogen, chlorine, ash and alkaline metal content, the results presented in Baxter et al., [2] indicate that slagging, fouling and corrosion is still most probable in most crops. Thus, the reduction in nutrients brought about by overwintering is still insufficient to lead to safe combustion […].» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  89. ^ Ren, X., Sun, R., Chi, H.-H., Meng, X., Li, Y., & Levendis, Y. A. (2017). Hydrogen chloride emissions from combustion of raw and torrefied biomass. Fuel, 200, page 40. https://doi.org/10.1016/j.fuel.2017.03.040
  90. ^ Ren, X., Sun, R., Chi, H.-H., Meng, X., Li, Y., & Levendis, Y. A. (2017). Hydrogen chloride emissions from combustion of raw and torrefied biomass. Fuel, 200, page 45. https://doi.org/10.1016/j.fuel.2017.03.040
  91. ^ Ren, X., Sun, R., Chi, H.-H., Meng, X., Li, Y., & Levendis, Y. A. (2017). Hydrogen chloride emissions from combustion of raw and torrefied biomass. Fuel, 200, page 45. https://doi.org/10.1016/j.fuel.2017.03.040
  92. ^ Harpreet Singh Kambo, Animesh Dutta, Comparative evaluation of torrefaction and hydrothermal carbonization of lignocellulosic biomass for the production of solid biofuel, Energy Conversion and Management, Volume 105, 2015, Figure 2, Page 752, ISSN 0196-8904, https://doi.org/10.1016/j.enconman.2015.08.031
  93. ^ Johansen et al. found that «[…] Cl [chlorine] is the main facilitator for K [potassium] release through sublimation [direct gas release] of KCl [potassium chloride] […].» Joakim M. Johansen, Jon G. Jakobsen, Flemming J. Frandsen, and Peter Glarborg. Release of K, Cl, and S during Pyrolysis and Combustion of High-Chlorine Biomass. Energy & Fuels 2011 25 (11), page 4961, https://doi.org/10.1021/ef201098n Potassium chloride is the «[…] dominant Cl species found in biomass, […]» and it remains stable in the solid phase until temperatures reach 700-800 °C. Ibid, page 4962. Note that a small amount (5-10 %) of potassium release has been observed at temperatures below 700 °C. Ibid, page 4969. At the threshold point, «[…] the high temperature release of K [potassium] in the form of KCl [potassium chloride] is equivalent to the available amount of total Cl [chlorine] in the feedstock fuel.» Ibid, page 4968. In other words, the «[…] K [potassium] release seems to be limited by the quantity of available Cl [chlorine].» Thus, it is mainly the bonding with chlorine that makes it possible for potassium to become a gas and foul the inside of the combustion equipment; the release of potassium «[…] will cease as the fuel, undergoing pyrolysis or combustion, reaches a state of complete dechlorination.» At this point, potassium will instead fuse with silicates and aluminiosilicates at approximately 800 °C, and will be retained in the ash. Ibid, page 4962.
  94. ^ Li, Yueh-Heng & Lin, Hsien-Tsung & Xiao, Kai-Lin & Lasek, Janusz, 2018. "Combustion behavior of coal pellets blended with Miscanthus biochar," Energy, Elsevier, vol. 163(C), page 182. https://doi.org/10.1016/j.energy.2018.08.117
  95. ^ Bridgeman, T. G., Jones, J. M., Shield, I., & Williams, P. T. (2008). Torrefaction of reed canary grass, wheat straw and willow to enhance solid fuel qualities and combustion properties. Fuel, 87(6), page 845. https://doi.org/10.1016/j.fuel.2007.05.041
  96. ^ «Recent studies by Reza et al. [18] and Smith et al. [19] have reported of the fate of inorganics and heteroatoms during HTC [hydrothermal carbonisation] of Miscanthus and indicate significant removal of the alkali metals, potassium and sodium, along with chlorine. […] Analysis of ash melting behaviour in Smith et al., [19] showed a significant reduction in the slagging propensity of the resulting fuel, along with the fouling and corrosion risk combined. […] Consequently HTC offers the potential to upgrade Miscanthus from a reasonably low value fuel into a high grade fuel, with a high calorific value, improved handling properties and favourable ash chemistry. […] HTC at 250 °C can overcome slagging issues and increase the ash deformation temperature from 1040 °C to 1320 °C for early harvested Miscanthus. The chemistry also suggests a reduction in fouling and corrosion propensity for both 250 °C treated fuels.» Aidan Mark Smith, Carly Whittaker, Ian Shield, Andrew Barry Ross, The potential for production of high quality bio-coal from early harvested Miscanthus by hydrothermal carbonisation, Fuel, Volume 220, 2018, Pages 546-557, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2018.01.143.  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  97. ^ Ribeiro, J.M.C.; Godina, R.; Matias, J.C.O.; Nunes, L.J.R. Future Perspectives of Biomass Torrefaction: Review of the Current State-Of-The-Art and Research Development. Sustainability 2018, 10, 2323. https://doi.org/10.3390/su10072323
  98. ^ "Secretariat – IBTC".
  99. ^ Michael Wild: «Torrefied biomass: The perfect CO2 neutral coal substitute is maturing.» VGB PowerTech 7 2015. http://www.bioendev.se/wordpress/wp-content/uploads/2015/09/VGB-PowerTech-2015-07-072-075-WILD-Autorenexemplar1.pdf
  100. ^ «A life‐cycle perspective of the relative contributions and variability of soil carbon stock change and nitrogen‐related emissions to the net GHG intensity (g CO2‐eq MJ−1) [gram CO2-equivalents per megajoule] of biofuel production via select production pathways (feedstock/prior land‐use/fertilizer/conversion type). Positive and negative contributions to life‐cycle GHG emissions are plotted sequentially and summed as the net GHG intensity for each biofuel scenario, relative to the GHG intensity of conventional gasoline (brown line) and the 50% and 60% GHG savings thresholds (US Renewable Fuel Standard and Council Directive 2015/1513); orange and red lines, respectively. Default life‐cycle GHG source estimates are taken from Wang et al. (2012) and Dunn et al. (2013); direct N2O emissions from Fig. 1; and soil carbon stock change (0–100 cm depth) from Qin et al. (2016). See Appendix S1 for detailed methods.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  101. ^ «Whilst these values represent the extremes, they demonstrate that site selection for bioenergy crop cultivation can make the difference between large GHG savings or losses, shifting life‐cycle GHG [green house gas] emissions above or below mandated thresholds. Reducing uncertainties in ∆C [carbon increase or decrease] following LUC [land use change] is therefore more important than refining N2O [nitrous oxide] emission estimates (Berhongaray et al., 2017). Knowledge on initial soil carbon stocks could improve GHG savings achieved through targeted deployment of perennial bioenergy crops on low carbon soils (see section 2). […] The assumption that annual cropland provides greater potential for soil carbon sequestration than grassland appears to be over‐simplistic, but there is an opportunity to improve predictions of soil carbon sequestration potential using information on the initial soil carbon stock as a stronger predictor of ∆C [change in carbon amount] than prior land use.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  102. ^ «Fig. 3 confirmed either no change or a gain of SOC [soil organic carbon] (positive) through planting Miscanthus on arable land across England and Wales and only a loss of SOC (negative) in parts of Scotland. The total annual SOC change across GB in the transition from arable to Miscanthus if all nonconstrained land was planted with would be 3.3 Tg C yr−1 [3.3 million tonnes carbon per year]. The mean changes for SOC for the different land uses were all positive when histosols were excluded, with improved grasslands yielding the highest Mg C ha−1 yr−1 [tonnes carbon per hectare per year] at 1.49, followed by arable lands at 1.28 and forest at 1. Separating this SOC change by original land use (Fig. 4) reveals that there are large regions of improved grasslands which, if planted with bioenergy crops, are predicted to result in an increase in SOC. A similar result was found when considering the transition from arable land; however for central eastern England, there was a predicted neutral effect on SOC. Scotland, however, is predicted to have a decrease for all land uses, particularly for woodland due mainly to higher SOC and lower Miscanthus yields and hence less input.» Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: 317-333. https://doi.org/10.1111/gcbb.12263  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  103. ^ The above-ground circulation is driven by photosynthesis and combustion – first, the miscanthus fields absorb CO2 and assimilates it as carbon in its [[Tissue (biology]|tissue]] both above and below ground. When the above-ground carbon is harvested and burned, it is released back into the atmosphere, in the form of CO2. However, an equivalent amount of CO2 (and possibly more, if the biomass is expanding) is absorbed back by next season's growth, and the cycle repeats.
  104. ^ «The environmental costs and benefits of bioenergy have been the subject of significant debate, particularly for first‐generation biofuels produced from food (e.g. grain and oil seed). Studies have reported life‐cycle GHG savings ranging from an 86% reduction to a 93% increase in GHG emissions compared with fossil fuels (Searchinger et al., 2008; Davis et al., 2009; Liska et al., 2009; Whitaker et al., 2010). In addition, concerns have been raised that N2O emissions from biofuel feedstock cultivation could have been underestimated (Crutzen et al., 2008; Smith & Searchinger, 2012) and that expansion of feedstock cultivation on agricultural land might displace food production onto land with high carbon stocks or high conservation value (i.e. iLUC) creating a carbon debt which could take decades to repay (Fargione et al., 2008). Other studies have shown that direct nitrogen‐related emissions from annual crop feedstocks can be mitigated through optimized management practices (Davis et al., 2013) or that payback times are less significant than proposed (Mello et al., 2014). However, there are still significant concerns over the impacts of iLUC, despite policy developments aimed at reducing the risk of iLUC occurring (Ahlgren & Di Lucia, 2014; Del Grosso et al., 2014).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  105. ^ «The impact of growing bioenergy and biofuel feedstock crops has been of particular concern, with some suggesting the greenhouse gas (GHG) balance of food crops used for ethanol and biodiesel may be no better or worse than fossil fuels (Fargione et al., 2008; Searchinger et al., 2008). This is controversial, as the allocation of GHG emissions to the management and the use of coproducts can have a large effect on the total carbon footprint of resulting bioenergy products (Whitaker et al., 2010; Davis et al., 2013). The potential consequences of land use change (LUC) to bioenergy on GHG balance through food crop displacement or ‘indirect’ land use change (iLUC) are also an important consideration (Searchinger et al., 2008).» Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: 317-333. https://doi.org/10.1111/gcbb.12263  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  106. ^ «While the initial premise regarding bioenergy was that carbon recently captured from the atmosphere into plants would deliver an immediate reduction in GHG emission from fossil fuel use, the reality proved less straightforward. Studies suggested that GHG emission from energy crop production and land-use change might outweigh any CO2 mitigation (Searchinger et al., 2008; Lange, 2011). Nitrous oxide (N2O) production, with its powerful global warming potential (GWP), could be a significant factor in offsetting CO2 gains (Crutzen et al., 2008) as well as possible acidification and eutrophication of the surrounding environment (Kim & Dale, 2005). However, not all biomass feedstocks are equal, and most studies critical of bioenergy production are concerned with biofuels produced from annual food crops at high fertilizer cost, sometimes using land cleared from natural ecosystems or in direct competition with food production (Naik et al., 2010). Dedicated perennial energy crops, produced on existing, lower grade, agricultural land, offer a sustainable alternative with significant savings in greenhouse gas emissions and soil carbon sequestration when produced with appropriate management (Crutzen et al., 2008; Hastings et al., 2008, 2012; Cherubini et al., 2009; Don- dini et al., 2009a; Don et al., 2012; Zatta et al., 2014; Rich- ter et al., 2015).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 490. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  107. ^ «Significant reductions in GHG emissions have been demonstrated in many LCA studies across a range of bioenergy technologies and scales (Thornley et al., 2009, 2015). The most significant reductions have been noted for heat and power cases. However, some other studies (particularly on transport fuels) have indicated the opposite, that is that bioenergy systems can increase GHG emissions (Smith & Searchinger, 2012) or fail to achieve increasingly stringent GHG savings thresholds. A number of factors drive this variability in calculated savings, but we know that where significant reductions are not achieved or wide variability is reported there is often associated data uncertainty or variations in the LCA methodology applied (Rowe et al., 2011). For example, data uncertainty in soil carbon stock change following LUC has been shown to significantly influence the GHG intensity of biofuel production pathways (Fig. 3), whilst the shorter term radiative forcing impact of black carbon particles from the combustion of biomass and biofuels also represents significant data uncertainty (Bond et al., 2013).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  108. ^ «After centuries of burning wood for energy or processing forage into horse power, the first generation of bioenergy feedstocks were food crops, such as maize, oil seed rape, sugar cane, and oil palm, used to produce bioethanol and biodiesel. These required a high input in terms of fertilizer and energy, which increased their carbon footprint (St. Clair et al., 2008). In addition, the carbon cost of converting the food crop feedstock to bioethanol or biodiesel was significant with a low ratio of energy produced to energy input, high GHG cost and a low productivity in terms of GJ of energy per hectare of land (Hastings et al., 2012). Another drawback of using food crops for energy production is the pressure put on the balance of supply and demand for these feedstocks which can impact the cost of food (Valentine et al., 2011) and the increase of indirect land use change (ILUC) to increase the arable cropped area (Searchinger et al., 2008) which consequentially increases their environmental footprint. The second generation bioenergy crop Miscanthus almost always has a smaller environmental footprint than first generation annual bioenergy ones (Heaton et al., 2004, 2008; Clifton-Brown et al., 2008; Gelfand et al., 2013; McCalmont et al., 2015a; Milner et al., 2015). This is due to its perennial nature, nutrient recycling efficiency and need for less chemical input and soil tillage over its 20-year life-cycle than annual crops (St. Clair et al., 2008; Hastings et al., 2012). Miscanthus can be grown on agricultural land that is economically marginal for food crop production (Clifton-Brown et al., 2015).» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  109. ^ «Our work shows that crop establishment, yield and harvesting method affect the C. cost of Miscanthus solid fuel which for baled harvesting is 0.4 g CO2 eq. C MJ-1 for rhizome establishment and 0.74 g CO2 eq. C MJ-1 for seed plug establishment. If the harvested biomass is chipped and pelletized, then the emissions rise to 1.2 and 1.6 g CO2 eq. C MJ-1, respectively. The energy requirements for harvesting and chipping from this study that were used to estimate the GHG emissions are in line with the findings of Meehan et al. (2013). These estimates of GHG emissions for Miscanthus fuel confirm the findings of other Life Cycle Assessment (LCA) studies (e.g., Styles and Jones, 2008) and spatial estimates of GHG savings using Miscanthus fuel (Hastings et al., 2009). They also confirm that Miscanthus has a comparatively small GHG footprint due to its perennial nature, nutrient recycling efficiency and need for less chemical input and soil tillage over its 20-year life-cycle than annual crops (Heaton et al., 2004, 2008; Clifton-Brown et al., 2008; Gelfand et al., 2013; McCalmont et al., 2015a; Milner et al., 2015). In this analysis, we did not consider the GHG flux of soil which was shown to sequester on average in the United Kingdom 0.5 g of C per MJ of Miscanthus derived fuel by McCalmont et al. (2015a). Changes in SOC resulting from the cultivation of Miscanthus depend on the previous land use and associated initial SOC. If high carbon soils such as peatland, permanent grassland, and mature forest are avoided and only arable and rotational grassland with mineral soil is used for Miscanthus then the mean increase in SOC for the first 20-year crop rotation in the United Kingdom is ∼ 1–1.4 Mg C ha-1 y-1 (Milner et al., 2015). In spite of ignoring this additional benefit, these GHG cost estimates compare very favorably with coal (33 g CO2 eq. C MJ-1), North Sea Gas (16), liquefied natural gas (22), and wood chips imported from the United States (4). In addition, although Miscanthus production C. cost is only < 1/16 of the GHG cost of natural gas as a fuel (16–22 g CO2 eq. C MJ-1), it is mostly due to the carbon embedded in the machinery, chemicals and fossil fuel used in its production. As the economy moves away from dependence on these fossil fuels for temperature regulation (heat for glasshouse temperature control or chilling for rhizome storage) or transport, then these GHG costs begin to fall away from bioenergy production. It should be noted, the estimates in this paper do not consider either the potential to sequester C. in the soil nor any impact or ILUC (Hastings et al., 2009).» Hastings A, Mos M, Yesufu JA, McCalmont J, Schwarz K, Shafei R, Ashman C, Nunn C, Schuele H, Cosentino S, Scalici G, Scordia D, Wagner M and Clifton-Brown J (2017) Economic and Environmental Assessment of Seed and Rhizome Propagated Miscanthus in the UK. Frontiers in Plant Science 8:1058. https://doi.org/10.3389/fpls.2017.01058  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  110. ^ «Perennial Miscanthus has energy output/input ratios 10 times higher (47.3 ± 2.2) than annual crops used for energy (4.7 ± 0.2 to 5.5 ± 0.2), and the total carbon cost of energy production (1.12 g CO2-C eq. MJ-1) is 20–30 times lower than fossil fuels.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9. page 489. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  111. ^ «The results in Fig. 3c show most of the land in the UK could produce Miscanthus biomass with a carbon index that is substantially lower, at 1.12 g CO2-C equivalent per MJ energy in the furnace, than coal (33), oil (22), LNG (21), Russian gas (20), and North Sea gas (16) (Bond et al., 2014), thus offering large potential GHG savings over comparable fuels even after accounting for variations in their specific energy contents. Felten et al. (2013) found Miscanthus energy production (from propagation to final conversion) to offer far higher potential GHG savings per unit land area when compared to other bioenergy systems. They found Miscanthus (chips for domestic heating) saved 22.3 ± 0.13 Mg [tonnes] CO2-eq ha-1 yr-1 [CO2 equivalents per hectare per year] compared to rapeseed (biodiesel) at 3.2 ± 0.38 and maize (biomass, electricity, and thermal) at 6.3 ± 0.56. Only the low-input Miscanthus was found to be effectively a CO2 sink. Styles & Jones (2007) calculated GHG savings for Miscanthus in Ireland at 35 Mg CO2-eq ha-1 yr-1, while Brandao et al. (2011) gave a figure of 11.01 for the UK. Of course these savings are determined by the specific energy source they offset and comparisons do not always account for displaced production. Styles et al. (2015) investigated the effects of indirect land-use change, that is considering GHG emissions from the production of food displaced by bioenergy feedstock production. They found only Miscanthus and rotational maize offered GHG savings when these indirect land-use change (iLUC) impacts were considered and the percentage of displaced production that was directly replaced determined a threshold. Typically replacing 2– 14% for food crops or grassland diverted into anaerobic digestion negated potential GHG savings, whereas it was around 85% for pelletized Miscanthus. The GHG benefits for rotational maize were, however, heavily offset by ecosystem service impacts due to intensive production, and of the six bioenergy crop systems investigated, Miscanthus was shown to offer the greatest benefits in ecosystem service provision. It was stressed, though, that these positive effects could be localized, consideration needed to be given where production might be displaced to and the impacts of any land-use changes incurred. The importance of understanding indirect land-use change was also highlighted by Tonini et al. (2012) who used sensitivity analysis to show that uncertainties around this were significant determinants in LCA results. They compared four conversion pathways (AD, gasification, small-scale CHP, and large-scale cofiring with coal) for ryegrass, willow, and Miscanthus and found that when considering their Danish systems, only large-scale cofiring of Miscanthus and willow offered real GHG savings compared to fossil fuel alternatives.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 500. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  112. ^ «The costs and life-cycle assessment of seven miscanthus-based value chains, including small- and large-scale heat and power, ethanol, biogas, and insulation material production, revealed GHG-emission- and fossil-energy-saving potentials of up to 30.6 t CO2eq C ha−1 y−1 and 429 GJ ha−1 y−1, respectively. Transport distance was identified as an important cost factor. Negative carbon mitigation costs of –78€ t−1 CO2eq C were recorded for local biomass use. The OPTIMISC results demonstrate the potential of miscanthus as a crop for marginal sites and provide information and technologies for the commercial implementation of miscanthus-based value chains. […] The overall biomass transport distance was assumed to be 400 km when bales were transported to the bioethanol plant or to the plant producing insulation material as well as in the value chain “Combined heat and power (CHP) bales.” For the value chains “CHP pellets” and “Heat pellets” the bales were transported 100 km to a pelleting plant and from there the pellets were transported 400 km to the power plants. The average farm-to-field distance was assumed to be 2 km. This transport distance is also assumed for the value chain “heat chips” in which a utilization of the chips as a biomass fuel on the producing farm was assumed. Because of the higher biomass requirements of the biogas plant an average transport distance of 15 km from field to plant was assumed.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  113. ^ «The highest biomass yields as well as the highest GHG- and fossil-energy savings potentials (up to 30.6 t CO2eq/ha*a and 429 GJ/ha*a, respectively) can be achieved on non-marginal sites in Central Europe. On marginal sites limited by cold (Moscow/Russia) or drought (Adana/Turkey) savings of up to 19.2 t CO2eq/ha*a and 273 GJ/ha*a (Moscow) and 24.0 t CO2eq/ha*a and 338 GJ/ha*a (Adana) can be achieved. The GHG and fossil-energy savings are highest where miscanthus biomass is used as construction material (our analysis uses the example of insulation material). A high GHG- and fossil-energy-saving potential was also found for domestic heating on account of the short transportation distance. Pelleting is only advantageous in terms of the minimization of GHG emissions and energy consumption where biomass is transported over a long distance, for example for heat and power production in CHP. Pelleting requires additional energy, but at the same time reduces the energy required for transport due to its higher density. The lowest GHG- and fossil-energy-saving potentials were found for power production via the biogas pathway, followed by bioethanol. However, this result is strongly influenced by the assumptions that (a) only 50% of the available heat is used and (b) transport distance from the field to the biogas plant is relatively long (15 km). A biogas chain with 100% heat utilization and lower transportation distances would perform better. It can be concluded that for power generation from miscanthus biomass, the most favorable pathway is combustion for base load power, and biogas to cover peak loads.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  114. ^ «However, most bioenergy is produced with conventional annual crops, such as maize and oilseed rape. These crop types are known for high greenhouse gas emissions during crop production, including possible negative effects on soil organic carbon (SOC) stocks (Don et al., 2012). As alternative, new perennial crops such as switchgrass, Miscanthus and tree species in short rotation coppices are getting increasing attention as bioenergy source. These perennial crops have a much lower fertilizer demand as compared with conventional crops, reducing the nitrous oxide emissions, and have the potential to sequester additional SOC (Anderson-Teixeira et al., 2009). They are also able to meet the sustainability criteria of bioenergy set by the EU demanding a 50% mitigation effect by 2017, and a 60% effect by 2018 (Don et al., 2012). Therefore, the conversion of cropland to perennial bioenergy crop plantations is likely to become a spatially relevant European land-use change (LUC) in the next decades.» Poeplau, C. and Don, A. (2014), Soil carbon changes under Miscanthus driven by C4 accumulation and C3 decompostion – toward a default sequestration function. GCB Bioenergy, 6: page 327-328. https://doi.org/10.1111/gcbb.12043  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  115. ^ «Perennial bioenergy crops have significant potential to reduce greenhouse gas (GHG) emissions and contribute to climate change mitigation by substituting for fossil fuels; yet delivering significant GHG savings will require substantial land‐use change, globally. Over the last decade, research has delivered improved understanding of the environmental benefits and risks of this transition to perennial bioenergy crops, addressing concerns that the impacts of land conversion to perennial bioenergy crops could result in increased rather than decreased GHG emissions. For policymakers to assess the most cost‐effective and sustainable options for deployment and climate change mitigation, synthesis of these studies is needed to support evidence‐based decision making. In 2015, a workshop was convened with researchers, policymakers and industry/business representatives from the UK, EU and internationally. Outcomes from global research on bioenergy land‐use change were compared to identify areas of consensus, key uncertainties, and research priorities. Here, we discuss the strength of evidence for and against six consensus statements summarising the effects of land‐use change to perennial bioenergy crops on the cycling of carbon, nitrogen and water, in the context of the whole life‐cycle of bioenergy production. Our analysis suggests that the direct impacts of dedicated perennial bioenergy crops on soil carbon and nitrous oxide are increasingly well understood and are often consistent with significant life cycle GHG mitigation from bioenergy relative to conventional energy sources. We conclude that the GHG balance of perennial bioenergy crop cultivation will often be favourable, with maximum GHG savings achieved where crops are grown on soils with low carbon stocks and conservative nutrient application, accruing additional environmental benefits such as improved water quality. The analysis reported here demonstrates there is a mature and increasingly comprehensive evidence base on the environmental benefits and risks of bioenergy cultivation which can support the development of a sustainable bioenergy industry.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  116. ^ Daniel Felten, Christoph Emmerling, Effects of bioenergy crop cultivation on earthworm communities—A comparative study of perennial (Miscanthus) and annual crops with consideration of graded land-use intensity, Applied Soil Ecology, Volume 49, 2011, pages 167. ISSN 0929-1393. https://doi.org/10.1016/j.apsoil.2011.06.001
  117. ^ «Felten & Emmerling (2011) compared earthworm abundance under a 15‐year‐old Miscanthus plantation in Germany to cereals, maize, OSR, grassland, and a 20‐year‐old fallow site (after previous cereals). Species diversity was higher in Miscanthus than that in annual crops, more in line with grassland or long‐term fallow with management intensity seen to be the most significant factor; the lower ground disturbance allowed earthworms from different ecological categories to develop a more heterogeneous soil structure. The highest number of species was found in the grassland sites (6.8) followed by fallow (6.4), Miscanthus (5.1), OSR (4.0), cereals (3.7), and maize (3.0) with total individual earthworm abundance ranging from 62 m−2 in maize sites to 355 m−2 in fallow with Miscanthus taking a medium position (132 m−2), although differences in abundance were not found to be significant between land uses. There is some trade‐off in this advantage for the earthworms however; the high‐nitrogen‐use efficiency and nutrient cycling which reduces the need for nitrogen fertilizer and its associated environmental harm means that, despite large volumes being available, Miscanthus leaf litter does not provide a particularly useful food resource due to its low‐nitrogen, high‐carbon nature (Ernst et al., 2009; Heaton et al., 2009) and earthworms feeding on this kind of low‐nitrogen material have been found in other studies to lose overall mass (Abbott & Parker, 1981). In contrast, though, the extensive litter cover at ground level under Miscanthus compared to the bare soil under annual cereals was suggested to be a potentially significant advantage for earthworms in soil surface moisture retention and protection from predation.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 502. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  118. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 128. http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  119. ^ «Our results show that young miscanthus stands sustain high plant species diversity before the canopy closure. Species richness was found to correlate negatively with the density of the stands and to be lower in mature plantations. However, even the 16-year-old, dense miscanthus plantations supported up to 16 different weed species per 25-m2 plot, accounting for up to 12% of the plantation. The literature data support this finding: Miscanthus stands are usually reported to support farm biodiversity, providing habitat for birds, insects, and small mammals (Semere and Slater, 2007a; Bellamy et al., 2009). Studies by Semere and Slater (2007b) have shown biodiversity in miscanthus to be higher than in other crop stands, but still lower than in open field margins.» Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  120. ^ «Our study suggests that miscanthus and SRC willows, and the management associated with perennial cropping, would support significant amounts of biodiversity when compared with annual arable crops. We recommend the strategic planting of these perennial, dedicated biomass crops in arable farmland to increase landscape heterogeneity and enhance ecosystem function, and simultaneously work towards striking a balance between energy and food security.» Haughton, A. J., Bohan, D. A., Clark, S. J., Mallott, M. D., Mallott, V. , Sage, R. and Karp, A. (2016), Dedicated biomass crops can enhance biodiversity in the arable landscape. GCB Bioenergy, 8: 1071-1081. https://doi.org/10.1111/gcbb.12312  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  121. ^ «Bellamy et al. (2009) looked at bird species and their food resources at six paired sites in Cambridgeshire comparing Miscanthus plantations up to 5 years old with winter wheat rotations in both the winter and summer breeding seasons. The authors found that Miscanthus offered a different ecological niche during each season; most of the frequently occurring species in the winter were woodland birds, whereas no woodland birds were found in the wheat; in summer, however, farmland birds were more numerous. More than half the species occurring across the sites were more numerous in the Miscanthus, 24 species recorded compared to 11 for wheat. During the breeding season, there was once again double the number of species found at the Miscanthus sites with individual abundances being higher for all species except skylark. Considering only birds whose breeding territories were either wholly or partially within crop boundaries, a total of seven species were found in the Miscanthus compared to five in the wheat with greater density of breeding pairs (1.8 vs. 0.59 species ha−1) and also breeding species (0.92 vs. 0.28 species ha−1). Two species were at statistically significant higher densities in the Miscanthus compared to wheat, and none were found at higher densities in the wheat compared to Miscanthus. As discussed, the structural heterogeneity, both spatially and temporally, plays an important role in determining within‐crop biodiversity, autumn‐sown winter wheat offers little overwinter shelter with ground cover averaging 0.08 m tall and very few noncrop plants, whereas the Miscanthus, at around 2 m, offered far more. In the breeding season, this difference between the crops remained evident; the wheat fields provided a uniform, dense crop cover throughout the breeding season with only tram lines producing breaks, whereas the Miscanthus had a low open structure early in the season rapidly increasing in height and density as the season progressed. Numbers of birds declined as the crop grew with two bird species in particular showing close (though opposite) correlation between abundance and crop height; red‐legged partridge declined as the crop grew, whereas reed warblers increased, and these warblers were not found in the crop until it had passed 1 m in height, even though they were present in neighbouring OSR fields and vegetated ditches. In conclusion, the authors point out that, for all species combined, bird densities in Miscanthus were similar to those found in other studies looking at SRC willow and set‐aside fields, all sites had greater bird densities than conventional arable crops. It is through these added resources to an intensive agricultural landscape and reductions in chemical and mechanical pressure on field margins that Miscanthus can play an important role in supporting biodiversity but must be considered complementary to existing systems and the wildlife that has adapted to it. Clapham et al. (2008) reports, as do the other studies here, that in an agricultural landscape, it is in the field margins and interspersed woodland that the majority of the wildlife and their food resources are to be found, and the important role that Miscanthus can play in this landscape is the cessation of chemical leaching into these key habitats, the removal of annual ground disturbance and soil erosion, improved water quality, and the provision of heterogeneous structure and overwinter cover.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 502-503. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  122. ^ «There is also a benefit of reduced chemical inputs and nitrate leaching associated with Miscanthus, significantly improving water quality running off farmland (Christian & Riche, 1998; Curley et al., 2009). McIsaac et al. (2010) reported that inorganic N leaching was significantly lower under unfertilized Miscanthus (1.5–6.6 kg N ha-1 yr-1) than a maize/soya bean rotation (34.2–45.9 kg N ha-1 yr-1).» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 501. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  123. ^ «Significant reductions in leaching of dissolved inorganic nitrogen on a land surface basis are predicted to occur if land already growing maize for ethanol production is converted to a perennial feedstock (Davis et al., 2012; Iqbal et al., 2015). This reduction in leaching is attributed to lower fertilizer requirements, the continuous presence of a plant root sink for nitrogen, and the efficient internal recycling of nutrients by perennial grass species (Amougou et al., 2012; Smith et al., 2013). In support of this, Miscanthus and switchgrass assessed at a plot scale had significantly lower dissolved inorganic nitrogen leaching from subterranean drainage tiles relative to the typical maize/soy rotation, with fertilized plots of switchgrass showing little or no leaching after reaching maturity (Smith et al., 2013). Similarly, results from soil‐based measurements in the same feedstocks showed lower dissolved inorganic nitrogen relative to annual crops (McIsaac et al., 2010; Behnke et al., 2012). A recent meta‐analysis of the available literature concluded that switchgrass and Miscanthus had nine times less subsurface loss of nitrate compared to maize or maize grown in rotation with soya bean (Sharma & Chaubey, 2017). At the basin scale, displacement of maize production for ethanol by cellulosic perennial feedstock production could reduce total leaching by up to 22%, depending on the type of feedstock and management practice employed (Davis et al., 2012; Smith et al., 2013). While these previous studies provide evidence for the potential ecosystem services of transitioning to cellulosic production, it is yet to be established what the total change to dissolved inorganic nitrogen export and streamflow would be under such scenarios. Hydrological processes are tightly coupled to the nitrogen cycle (Castellano et al., 2010, 2013), are key drivers of dissolved inorganic nitrogen transport through streams and rivers (Donner et al., 2002), and are sensitive to LUC (Twine et al., 2004). Various modelling scenarios, where current land cover over the Mississippi River Basin of the United States was altered to accommodate varying proportions of switchgrass or Miscanthus, showed that the impact on streamflow was small relative to the improvement in water quality (VanLoocke et al., 2017).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  124. ^ «Blanco-Canqui (2010) point out that this water-use and nutrient efficiency can be a boon on compacted, poorly drained acid soils, highlighting their possible suitability for marginal agricultural land. The greater porosity and lower bulk density of soils under perennial energy grasses, resulting from more fibrous, extensive rooting systems, and reduced ground disturbance, improves soil hydraulic properties, infiltration, hydraulic conductivity, and water storage compared to annual row crops. There may be potentially large impacts on soil water where plantation size is mismatched to water catchment or irrigation availability but note that increased ET and improved ground water storage through increased porosity could be beneficial during high rainfall with storage capability potentially increased by 100 to 150 mm.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 501. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  125. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 130. http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  126. ^ Nsanganwimana, F., Pourrut, B., Mench, M., Douay, F. (2014). Suitability of Miscanthus species for managing inorganic and organic contaminated land and restoring ecosystem services. A review. International Journal of Phytoremediation, 143 (10), page 131. http://www.academia.edu/28286459/Suitability_of_Miscanthus_species_for_managing_inorganic_and_organic_contaminated_land_and_restoring_ecosystem_services._A_review
  127. ^ Lewandowski I, Clifton-Brown J, Trindade LM, van der Linden GC, Schwarz K-U, Müller-Sämann K, Anisimov A, Chen C-L, Dolstra O, Donnison IS, Farrar K, Fonteyne S, Harding G, Hastings A, Huxley LM, Iqbal Y, Khokhlov N, Kiesel A, Lootens P, Meyer H, Mos M, Muylle H, Nunn C, Özgüven M, Roldán-Ruiz I, Schüle H, Tarakanov I, van der Weijde T, Wagner M, Xi Q and Kalinina O (2016) Progress on Optimizing Miscanthus Biomass Production for the European Bioeconomy: Results of the EU FP7 Project OPTIMISC. Frontiers in Plant Science 7:1620, page 2. https://doi.org/10.3389/fpls.2016.01620  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  128. ^ «This study distils a large body of literature into simple statements around the environmental costs and benefits of producing Miscanthus in the UK, and while there is scope for further research, particularly around hydrology at a commercial scale, biodiversity in older plantations or higher frequency sampling for N2O in land-use transitions to and from Miscanthus, clear indications of environmental sustainability do emerge. Any agricultural production is primarily based on human demand, and there will always be a trade-off between nature and humanity or one benefit and another; however, the literature suggests that Miscanthus can provide a range of benefits while minimizing environmental harm. Consideration must be given to appropriateness of plantation size and location, whether there will be enough water to sustain its production and the environmental cost of transportation to end-users; its role as a long-term perennial crop in a landscape of rotational agriculture must be understood so as not to interfere with essential food production. There is nothing new in these considerations, they lie at the heart of any agricultural policy, and decision-makers are familiar with these issues; the environmental evidence gathered here will help provide the scientific basis to underpin future agricultural policy.» McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 504. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  129. ^ McCalmont, J. P., Hastings, A. , McNamara, N. P., Richter, G. M., Robson, P. , Donnison, I. S. and Clifton‐Brown, J. (2017), Environmental costs and benefits of growing Miscanthus for bioenergy in the UK. GCB Bioenergy, 9, page 489. https://doi.org/10.1111/gcbb.12294  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  130. ^ «The approach to evaluating ES [ecosystem services] suggests that the growth of 2G bioenergy crops across GB broadly produces beneficial effects when replacing first‐generation crops (Table 1). Beneficial effects on the overall ecosystem rather than specific ES are in agreement with recent reports in the literature (Semere & Slater, 2007a,b; Rowe et al., 2009; Dauber et al., 2010). Benefits of a transition to 2G crops include increased farm‐scale biodiversity (Rowe et al., 2011), improved functional attributes such as predation (Rowe et al., 2013) and a net GHG mitigation benefit (Hillier et al., 2009). Benefits are primarily consequence of low inputs and longer management cycles associated with 2G crops (Clifton‐Brown et al., 2008; St Clair et al., 2008). The benefits may have distinct temporal patterns as establishment and harvest phases of 2G crop production are disruptive and have a short‐term negative impact on ES (Donnelly et al., 2011), although practices could be tailored to ameliorate these; however, this temporal effect has not been considered here and is similar to harvesting and planting food crops, grass or trees. […] When land is filtered for different planting scenarios under ALC 3 and 4, >92.3% available land will offer a positive ES effect when planting Miscanthus or SRC and such transitions are likely to create a net improvement in GHG balance.» Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: 317-333. https://doi.org/10.1111/gcbb.12263  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  131. ^ «[S]outh‐west and north‐west England were identified as areas where Miscanthus and SRC [Short Rotation Coppice] could be grown, respectively, with favourable combinations of economic viability, carbon sequestration, high yield and positive ES [Ecosystem Services] benefits. Beneficial impacts were found on 146 583 and 71 890 ha when planting Miscanthus or SRC, respectively, under baseline planting conditions rising to 293 247 and 91 318 ha, respectively, under 2020 planting scenarios. […] In Great Britain (GB), there are approximately 22.9 M ha of land in total (Lovett et al., 2014). […] The land available for planting was calculated using constraints maps produced by Lovett et al. (2014) using social and environmental constraints based on 8 factors: road, river and urban areas; slope > 15%; monuments; designated areas; existing protected woodlands; high organic carbon soils; and areas with a high ‘naturalness score’ such as National Parks and Areas of Outstanding Natural Beauty. This land availability was further constrained using agricultural land classes (ALC) (Lovett et al., 2014) in GB as summarized in Table 7, accomplished by aggregating a map of the ALC data at 100 m2 raster resolution to derive total hectares of land in different ALC in each 1 km2 grid cell. […] The effect of each bioenergy land use transition on ES [Ecosystem Services] is predominantly governed by the initial land uses (Table 1) and, to a lesser extent, linked to the underpinning research available for a particular crop type. When changing from improved and semi‐improved grassland, the choice of bioenergy crops had no overall impact on the ES score with each transition giving an ES score of 4. These transitions were largely governed by neutral effects on ES suggested by the available literature. In general, loss of forestry/woodland had a negative impact on ES score, irrespective of bioenergy crop type (Table 1). Choice of bioenergy crop had only a small effect on transitions from forestry/woodland, with the two short‐rotation woody crops (SRC and SRF) and Miscanthus scoring −8 and −9, respectively. Bioenergy crop choice had a more pronounced and positive effect for the transition from arable land use, with Miscanthus, SRC and SRF scoring 37, 43 and 19 respectively, reflecting a well‐developed understanding of the implications of different transitions and considerable published research evidence to confirm this metric. As considerably fewer papers are available in the literature on the ES effects of transitions to SRF, the confidence level was scored lower, creating a lower overall ES impacts score and thus impacting on results. » Milner, S. , Holland, R. A., Lovett, A. , Sunnenberg, G. , Hastings, A. , Smith, P. , Wang, S. and Taylor, G. (2016), Potential impacts on ecosystem services of land use transitions to second‐generation bioenergy crops in GB. GCB Bioenergy, 8: 317-333. https://doi.org/10.1111/gcbb.12263  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  132. ^ «[…] [E]vidence does indicate that the use of low‐input perennial crops, such as SRC, Miscanthus and switchgrass, can provide significant GHG savings compared to fossil fuel alternatives provided that reasonable yields are obtained, low carbon soils are targeted (see sections 2 and 3 above), and the development context is one where tension with land use for food (and associated potential for iLUC emissions) is mitigated. There are many cases where these criteria are satisfied. It is, however, important that robust analysis of potential land‐use tensions is carried out using sensible yield assumptions. Legislative/policy focus may be on supply chains, and this has, to some extent, driven the concept of iLUC. However, in assessing the sustainability of bioenergy, it makes much more sense to view production of food and energy holistically and evaluate trade‐offs in land use at a much larger (global) scale (Njakou Djomo & Ceulemans, 2012). Increasing our knowledge of drivers of land‐use change and shifts in land management practice would therefore help us understand the likelihood of substantial climate mitigation being achieved.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  133. ^ «In contrast to annual crops, bioenergy from dedicated perennial crops is widely perceived to have lower life‐cycle GHG emissions and other environmental cobenefits (Rowe et al., 2009; Creutzig et al., 2015). Perennial crops such as Miscanthus and short‐rotation coppice (SRC) willow and poplar have low nitrogen input requirements (with benefits for N2O emissions and water quality), can sequester soil carbon due to reduced tillage and increased belowground biomass allocation, and can be economically viable on marginal and degraded land, thus minimizing competition with other agricultural activities and avoiding iLUC effects (Hudiburg et al., 2015; Carvalho et al., 2017). With respect to the perennial crop sugarcane, large GHG savings can be achieved due to high crop productivity and the use of residues for cogeneration of electricity, whilst the recent shift to mechanized harvest without burning in Brazil should also increase the potential for soil carbon sequestration (Silva‐Olaya et al., 2017). Nevertheless, the site‐level impacts of perennial crop cultivation on ecosystem carbon storage (resulting from dLUC) vary geographically, dependent on soil type and climate (Field et al., 2016).» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  134. ^ «In the rush to pursue climate change mitigation strategies, the ‘carbon neutrality’ of bioenergy was not rigorously assessed. As more studies began to include assessment of dLUC and iLUC impacts, the credibility of first‐generation bioenergy as an environmentally sustainable, renewable energy source was damaged. In recent years, a more nuanced understanding of the environmental benefits and risks of bioenergy has emerged, and it has become clear that perennial bioenergy crops have far greater potential to deliver significant GHG savings than the conventional crops currently being grown for biofuel production around the world (e.g. corn, palm oil and oilseed rape). Furthermore, the increasingly stringent GHG savings thresholds for biofuels and bioenergy being introduced in Europe (Council Corrigendum 2016/0382(COD)) and the US (110th Congress of the United States 2007) are providing increased impetus for this transition to perennial bioenergy crops.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  135. ^ «Considered in a whole life‐cycle context, these approaches have delivered robust evidence that bioenergy produced from dedicated perennial feedstocks can deliver significant GHG savings compared to fossil fuel systems (sections 3 and 4), as well as additional environmental benefits such as improved water quality (section 5). However, soil type, climate, prior land use and land management can significantly influence the net GHG intensity of perennial bioenergy crops (sections 1, 2, 3 and 6), and there is therefore a risk that not all bioenergy production pathways will deliver the GHG savings targeted in some renewable fuel policies (sections 3 and 4). […] Our analysis suggests that the direct impacts of dedicated perennial bioenergy crops on soil carbon and N2O are increasingly well understood, and are often consistent with significant lifecycle GHG mitigation from bioenergy relative to conventional energy sources.» Whitaker, J. , Field, J. L., Bernacchi, C. J., Cerri, C. E., Ceulemans, R. , Davies, C. A., DeLucia, E. H., Donnison, I. S., McCalmont, J. P., Paustian, K. , Rowe, R. L., Smith, P. , Thornley, P. and McNamara, N. P. (2018), Consensus, uncertainties and challenges for perennial bioenergy crops and land use. GCB Bioenergy, 10: 150-164. https://doi.org/10.1111/gcbb.12488  This article incorporates text available under the CC BY 4.0 license. (The CC BY 4.0 licence means that everyone have the right to reuse the text that is quoted here, or other parts of the original article itself, if they credit the authors. More info: https://en.wikipedia.org/wiki/Creative_Commons_license)
  136. ^ Emily Heaton, and Danielle Wilson. "Giant Miscanthus Establishment" Iowa State University." https://store.extension.iastate.edu/Product/Giant-Miscanthus-Establishment-PDF.