Seed ball

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Seed ball
Activities for making Mud Seed ball
Mud Seed ball
drying mud seed balls in shed

Seed balls, also known as "earth balls" or nendo dango (Japanese: 粘土団子), consist of a variety of different seeds rolled within a ball of clay, preferably volcanic pyroclastic red clay. Various additives may be included, such as humus or compost. These are placed around the seeds, at the center of the ball, to provide microbial inoculants. Cotton-fibres or liquefied paper are sometimes mixed into the clay in order to strengthen it, or liquefied paper mash coated on the outside to further protect the clay ball during sowing by throwing, or in particularly harsh habitats.

Development of technique[edit]

The technique for creating seed balls was rediscovered by Japanese natural farming pioneer Masanobu Fukuoka.[1] The technique was also used, for instance, in ancient Egypt to repair farms after the annual spring flooding of the Nile. In modern times, during the period of the Second World War, this Japanese government plant scientist working in a government lab, Fukuoka, who lived on the mountainous island of Shikoku, wanted to find a technique that would increase food production without taking away from the land already allocated for traditional rice production which thrived in the volcanic rich soils of Japan.[2][3]


To make a seed ball, generally about five measures of red clay by volume are combined with one measure of seeds. The balls are formed between 10mm and 80mm (about 0.4 to 3.15 inches) in diameter.

Seed bombing[edit]

Seed bombing, or in some cases aerial reforestation,[4] is a technique of introducing vegetation to land by throwing or dropping seed balls.

Sowing tree seeds directly in the field is an old technique but it was little used until the development of repellents to protect seed from insects, rodents, and birds.

Today aerial seeding is already regarded as a practical reforestation technique in a few countries. There it is fully operational. More than a million hectares of well-stocked forests in the United States, Canada, China, Australia, and New Zealand demonstrate its success. Some of these forests have been established despite seemingly adverse conditions-for example, on steep slopes and on overburden from strip mines.

Although aerial seeding technology has been used mainly in industrialized countries in temperate areas, it would seem the techniques could be modified for use elsewhere. Whether it will prove widely applicable in the arid tropics is still unknown but is undergoing trials in Kenya[5]. The uncertainties regarding its application in new regions lie mostly in whether the native animals and plants, as well as local climatic conditions and quality seed will permit its success. Nonetheless, sufficient knowledge has been accumulated in large-scale operations in North America and Australasia to justify wide-ranging trials in developing countries.[6]

'The earliest records of aerial reforestation date back to 1930. In this period, planes were used to distribute seeds over certain inaccessible mountains in Honolulu after forest fires.[4]

Aerial seeding is just one example of the more general process of broadcast seeding by which the seed may also be sown from the ground using mechanical spreaders or by hand. Ground-seeding methods will be preferable to aerial seeding in many situations in developing countries. In such cases, the principles and requirements are similar to those discussed here.

The advantage of the airplane/helicopter is its ability to quickly seed large areas, even remote areas, when conditions for prompt germination and survival are best.

Aerial seeding is best suited to sites whose remoteness, ruggedness, inaccessibility, or sparse population make seedling planting difficult. It is particularly appropriate for "protection forests" because helicopters or planes can easily spread seed over steep slopes or remote watersheds and isolated dryland areas. It seems well suited for use in areas where there may be a dearth of skilled laborers, supervisors, and funds for reforestation (Large tracts can be seeded so rapidly that supervising personnel are freed for other duties in a relatively short time. A ground crew of only three flagmen and two men to weigh and load seed are usually required). It has the potential to help increase production of tree crops for forage, food, and honey as well as wood for fuel, posts, lumber, charcoal and pulp.

In 1987, Lynn Garrison created the Haitian Aerial Reforestation Project (HARP) in which tons of seed would be scattered from specially modified aircraft. The seeds would be encapsulated in an absorbent material. This coating would contain fertilizer, insecticide/animal repellent and, perhaps a few vegetable seeds. Haiti has a bimodal rainy season, with precipitation in spring and fall. The seeds are moistened a few days before the drop, to start germination. Tons of seed can be scattered across areas in the mountains, inaccessible to hand-planting projects.

Another project idea was to use C-130 aircraft and altering them to drop biodegradable cones filled with fertilizer and saplings over hard-to-access areas.[7]

Seed bombing is also widely used in Africa; Especially in Kenya where millions are being made using biochar and are being spread in barren or simply areas that were recently deforested for charcoal and firewood extraction. With technology expanding, the contents of some seed bombs are now placed in a biodegradable container and "bombed" grenade-style onto the land. As the sprout grows, the container biodegrades into the soil. The process is usually done as a large-scale project with hundreds dropped in a single area at any one time. Provided enough water, adequate sunlight, and low competition from existing flora and fauna, seed-bombed barren land could be host to new plants in as little as a month.

Seed balls have use in nearly any region where plants can grow: for reseeding ecosystems into areas of man-made deserts, avoiding seed eating insects and animals and protecting seeds until rains fall to soak the clay ball and stimulate the seeds. Seeds contained in such balls then germinate in ideal conditions for each climate/region.

On the other hand, rapid deployment may not be practical in some cases because the site may require preparation or the season may be wrong. To germinate successfully, seeds usually must fall directly onto mineral soil rather than onto established vegetation or undecomposed organic matter. Where organic matter has accumulated thickly, the site must normally be burned, furrowed, or disked. The soil disturbance left after logging is often sufficient.

Rough terrain is especially amenable to broadcast seeding.

On certain sites ground preparation may be necessary. Site preparation and the seeding operation must be well coordinated to meet the biological requirements for prompt seed germination and seeding survival. Dry sites may have to be specially ridged or disked so as to optimize the rainfall that reaches the seed. Excessively wet sites may need to be ridged or drained. The degree of slope is not critical as long as seeds find a receptive seedbed. Steep watersheds, eroding mountain slopes, bare hillsides, and spoil-banks where vegetation is sparse are often suitable for aerial seeding (however, on some steep slopes with smooth, bare soil, rain may wash the seeds away too easily for successful seeding). On steep strip-mine spoils in West Virginia and in Indonesia slopes of more than 30° (about 70 percent slope) have been successfully revegetated from the air.

Arid and savanna lands (for example, those where annual rainfall is under 800 mm) are most in need of reforestation. These are regions where aerial seeding in principle has exceptional potential. They include vast tracts of unused or poorly used land that has sparse tree cover and that is not confined to private land holdings, so it is generally accessible to aircraft. The native trees (such as species of Acacia, and other genera) in these areas are generally well adapted for survival under difficult field conditions. These are not species for timber as much as for firewood, forage, fruit, gum, erosion control, and other such uses.

As a prerequisite to any method of reforestation, the species selected must be adapted to the temperature, length of growing season, rainfall, humidity, photoperiod, and other environmental features of the area. Ideally, before aerial seeding takes place trial plots should be established to test those species most likely to germinate and grow successfully on the chosen sites. Even when one species has the right characteristics, it may be prudent to test seed of different provenances to find those best suited to the site. Aerial seeding has been used mostly with conifers and eucalypts, although other species that reseed themselves successfully in a given region could also be aerially seeded with reasonable probability of success. However, in nature seed germinates over a relatively long period, and though environmental factors may be hostile at one time, they usually prove favorable at another. With broadcast seeding, only one or two applications are made, the seeds germinate together, and if timing is off, the results will be variable.

Characteristics that make a particular species appropriate for aerial seeding include:

  • small or medium-sized seed,
  • frequent and prolific seed availability,
  • ability of the seed to germinate on the soil surface,
  • fast germination and rapid seedling growth,
  • ability to withstand temperature extremes and prolonged dry periods (orthodox seed),
  • ability to tolerate a wide range of soil conditions,
  • high light tolerance,
  • seed that is easy to collect in large quantities and to store for long periods,
  • suitability of seed for handling with mechanical seeding devices,
  • rapid development of a deep taproot by seedlings to enable them to withstand adverse climatic conditions in the period following germination.

Species with highly palatable seeds have little prospect of success because wildlife eat the seed before it has a chance to germinate unless it is pelletized. Also, small seeds and lightweight, chaffy seeds are more likely to drift in the wind, so they are harder to target during the drop. (This can be compensated for by adding a thick coating to the seed.) Small seeds, however, fall into crevices and are then more likely to get covered with soil, thereby enhancing their chances of survival. Aerial seeding may prove to work best with "pioneer" species, which germinate rapidly on open sites, are adapted for growth on bare or disturbed areas, and grow well in direct sunlight.

Other aerial seeding platforms[edit]

Crop Spraying Aircraft: the only company in Kenya, Farmland Aviation, who can currently do this on a large industrial scale. They can spread up to six tons of tree seeds per hour over tens of thousands of acres.

Unmanned Aerial Vehicles: current day low-cost UAV's lack of payload capacity and range, limits them for most aerial seeding applications. Currently they seem to be best applied for be use in mapping and monitoring forests.

Paragliding: quite possible one of the best methods we have seen so far of adding tree seed distribution to existing flight plans would definitely have to be at Borana Kenya, they sometimes throw out seeds as they paraglide.

Guerrilla gardening[edit]

The term "seed green-aide" was first used by Liz Christy in 1973 when she started the "Green Guerrillas".[8] The first seed green-aides were made from condoms filled with tomato seeds, and fertilizer.[9] They were tossed over fences onto empty lots in New York City in order to make the neighborhoods look better. It was the start of the guerrilla gardening movement.[10]

See also[edit]


  1. ^ Adler, Margot (April 15, 2009). "Environmentalists Adopt New Weapon: Seed Balls". NPR. Retrieved November 9, 2011.
  2. ^ Fukuoka (福岡), Masanobu (正信) (May 1978) [1st publ. in Japanese September 1975 自然農法・わら一本の革命 (shizen nōhō・wara ippon no kakumei)], The One-Straw Revolution An Introduction to Natural Farming, translation: Chris Pearce, Tsune Kurosawa, and Larry Korn (ed.), Emmaus, Pennsylvania: Rodale Press, ISBN 0878572201
  3. ^ Fukuoka (福岡), Masanobu (正信) (December 1987) [1st publ. in Japanese December 1975 自然農法 緑の哲学の理論と実践 (shizen nōhō midori no tetsugaku no riron to jissen); 1st Eng. tr. ed. 1985], The Natural Way of Farming The Theory and Practice of Green Philosophy, translation: Frederic P Metreaud (rev. ed.), Tokyo: Japan Publications, ISBN 978-0-87040-613-3
  4. ^ a b Horton, Jennifer. "Could military strategy win the war on global warming?". How Stuff Works. Retrieved 2012-04-06.
  5. ^ Cookswell Jikos (2016-08-07), Dryland aerial forest restoration using biochar seedballs - Kenya Aug 2106 (Part I), retrieved 2018-03-25
  6. ^ Kairu, Pauline (December 9, 2017). "Meet the squad bombing forests to grow more trees - Daily Nation". Retrieved 2019-04-11.
  7. ^ Brown, Paul (1999-09-02). "Aerial bombardment to reforest the earth". The Guardian. Retrieved 2011-06-09.
  8. ^ "Our History | Green Guerillas". Retrieved 2017-12-31.
  9. ^ "How Guerrilla Gardening Works". How Stuff Works. Retrieved 2017-09-12.
  10. ^ Robinson, Joe (29 May 2008). "Guerrilla gardener movement takes root in L.A. area". L.A. Times. Retrieved 12 June 2014.

Further reading[edit]

  • Smith, K. (2007). The guerilla art kit. Princeton Architectural Press.
  • Huxta, B. (2009). Garden-variety graffiti. Organic gardening, 2009.

External links[edit]