|WikiProject Soil||(Rated Start-class, High-importance)|
Article initiated by
Paleorthid 01:44, 11 July 2005 (UTC)
Edaphology and Plants
Soil has 3 primary functions in sustaining plant life:
- It supplies mineral elements, serving both as a medium of exchange and as a place of storage.
- It supplies water and serves as a storage reservoir.
- It serves as a medium within which the roots of terrestrial plants, as well as those of many aquatic plants, anchor themselves.
Edaphic influences also include the following:
- soil temperatures determine the rates at which chemical reactions proceed.
- soil acts as a conduit for the exchange of soil gases with the atmosphere.
- microbial soil life influences a myriad of effects, including decomposition rates of pesticides and plant ability to absorb micronutrients and trace elements.
Changes in these edaphic conditions affect plant productivity as well as plant composition and response to inputs. For example, variations in soil can produce grasslands or shrub-steppe where otherwise forests might grow.
Edaphology and Man's Overall Use of the Land
Soil resources affect the health, functioning, and total productivity of all land uses, be they urban, rural or natural. Potential side effects of soil management and land-use decisions abound. Urban development follows soil resources and, in general, the best agricultural soils are preferentially converted to nonagricultural uses by urban growth. Regulatory efforts to divert urban growth to less productive soils can impair economic efficiency and threaten soil diversity.
Edaphology and Land Use
- Assessing the Impact of Urban Sprawl on Soil Resources in the United States Using Nighttime "City Lights" Satellite Images and Digital Soils Maps
Edaphology is a Part of Pedology
I believe that edaphology can be placed under pedology and has been placed alongside due to a misconception of what pedology is.
First, Buol et al. (1997) states that "pedology is a collective term used to refer to the combination of the two phases [of soil science] - soil genesis and classification. It has also been used to refer to the combination of the the entire subfield of soil genesis and classification, morphology, survey and interpretations." This authority then lists the following subareas of pedology:
* Soil Genesis * Soil Classification * Soil Morphology * Soil Survey * Soil Geomorphology * Soil Characterization and Analysis * Soil Interpretation
Wikipedia states that Edaphology "is concerned with the influence of soils on living things, particularly plants. The term is also applied to the study of how soil influences man's overall use of the land."
I contend that this Wikipedia statement is a misconception of what pedology encompasses. The soil forming factors climate, organisms, parent material, relief, and time include plant organisms (Jenny, 1994). Jenny (1994) states that plants have an intimate continuing interaction with the soil. Plants, as the most pronounced expression of organisms interaction with soils, should be viewed as a soil forming factor and a subset of pedology; Soil Genesis, Soil Characterization and Analysis, and Soil Interpretation. Plants alter the soil by removing inorganics, contributing to the dissolution of soil minerals by exuding protons and organic acids. Plants also exude other organic compounds to chelate inorganics either for uptake or to sequester them to avoid or mediate uptake. Soil influence on man's overall use is covered in Soil Interpretation, and the Soil Survey is a product that does just that.
Pedology is integrative of other soil science disciplines. A pedologist must be conversant with other sub-disciplines of Soil Science such as Soil Chemistry, Soil Physics, and Soil Biology (sometimes referred to as Soil Microbiology or Soil Ecology). The intensity of study within these sub-disciplines often precludes the time, resources, and understanding of other soil sub-disciplines that is necessary to link the findings of their investagations to the soilscape. However, these sub-disciplines are marked by being allied to one or more of the subareas of pedology, but, again, they often do not rely on the integration if the findings into an understanding of the soilscape for acceptance of the findings by the scientific community. Pedological results always link back to the soilscape.
soilman 18:29, 13 July 2007 (UTC)
- Edaphology can't be both a sub-discipline of pedology (contended above) and one of two main branches of soil science, per the reliable cited source used in the article. I accept that pedology is integrative of the other disciplines of soil science, but that doesn't mean that edaphology loses it's equal branch standing. The integrative position is the same logic that is used to dismiss soil science's equal standing with geology as a branch of the earth sciences, something which pedologists reject. Pedology is the study of soil in a natural setting, edaphology is the study of soil effects on (and from) plants, animals and man, some of which cannot occur in a natural setting. There is considerable overlap, but it is not complete. Regarding edaphology as an equal branch is necessary to allow soil science to cover the study of soil that exists outside of a natural context. -- Paleorthid 14:55, 3 December 2007 (UTC)
- It is particularly useful to maintain edaphology as a sister of pedology within the context of Wikipedia. Pedology, as distinct from edaphology, is accepted here as a sub-discipline of Category:Physical geography, a placement that has a long and substantial history to it. Vasily Dokuchaev, the father of modern soil science, was a geographer. What existed before Dokuchaev was edaphology sans pedology, and agricultural geology. This focus, soil science sans pedology, ie sans geography, continues to thrive, and will not conform to sub-discipline standing under pedology. See especially Agrogeologist, Agrogeology, Agroecology, Agrology, Agrominerals, Biogeochemistry, Biogeology. -- Paleorthid (talk) 18:41, 9 December 2007 (UTC)