Soil erosion processes

Toy, T.J., Foster, G.R. and Renard, K.C. (eds) (2002) Soil Erosion Processes, Prediction, Measurement, and Control. John Wiley Sons, New York, 352 pp. 

Soil is a key component of the rock cycle because weathering and soil formation processes transform rock into more readily erodible material. Rates of soil formation may even limit the overall erosion rate of a landscape. Erosion processes are also a key linkage in the rock cycle... 

EPIC is designed to simulate relevant biophysical processes simultaneously and realistically, using readily available input data and accepted methods. It is capable of simulating plant and soil response for hundreds of years, and it is applicable to a wide range of soils, climates, and plants. EPIC also simulates soil erosion and soil chemical and physical property changes over centuries. The time limit for simulation of hydrologic parameters is restricted only by the availability of high-quality climate input data. 

Instrumental knowledge is information about how to steer certain processes, on how to achieve certain goals, i.e. knowledge that needs to be balanced against regulation and safety. Examples how to build Bt and other genes into crops and how to stabilize them how to avoid vertical gene flow how to avoid unwelcome soil erosion how to avoid early pest resistance. 

The ecosystem acidification and critical load calculation processes are only partly scientific exercises, being connected closely with economic development of all countries. So, in different projects the hazards of concern include ecosystem damage due to acidification and eutrophication processes (e.g., decreased productivity and biodiversity, soil erosion, drinking water quality, reproduction losses, etc.), firstly, in local scale and, secondly, in regional scale that may lead to transboundary pollution. For more details see Figure 2. 

This mass balance presents the possible links in the biogeochemical food web for various heavy metals. Some items may be neglected, like degassing of Pb, Cd, Cu and Zn metals. However, this process is of crucial importance for mercury (see Section 3.2). The output of the heavy metals with soil erosion may also be neglected. After elimination of these processes, the simplified following equation is workable. The sum of inputs by deposition, fertilizing, and waste and rubbish as fertilizer stands as the term Critical Load . 

However, this is not the case for airborne particles composed of crustal materials formed by erosion processes. As discussed in Chapter 9.C, mineral dust consists primarily of such crustal materials. Despite the fact that soil dust particles tend to be quite large, of the order of a micron and larger, they can be carried large distances. These particles not only scatter and absorb solar radiation but also absorb long-wavelength infrared emitted by the earth s surface. 

Poppy cultivation and opium processing also have consequences for the environment. Waste from morphine extraction can cause environmental damage when dumped by processors. In addition to water pollution from this chemical dumping, other environmental concerns include the deforestation that may occur when clearing land for poppy cultivation, soil erosion, and dangers to wildlife in the area where these chemicals are dumped. 

Erosion from wind, water, or glaciers picks up materials from weathering rocks and deposits them as sediments or soil. A process called lithification describes the conversion of sediments to sedimentary rocks. In contrast to the parent igneous rocks, sediments and sedimentary rocks are porous, soft, and chemically reactive. Metamorphic rock is formed by the action of heat and pressure on sedimentary, igneous, or other kinds of metamorphic rock that are not in a molten state. 

In small-scale farm production of ethanol a possible environmental impact could occur through removal of crop residues for use as a boiler fuel. Crop residues are important because they help control soil erosion through their cover and provide nutrients, minerals, and fibrous material which help maintain soil quality. However, not more than one-third to one-half of the residues from a grain crop devoted to ethanol production need be used to fuel the process. Also, there are several methods, such as crop rotation and winter cover crops, which lessen the impact of crop residue removal. ... 

Soil erosion A process whereby wind and water carry away soil, depleting the amount of soil available. Human activity, such as overcultivation and compaction, can also lead to soil erosion. 

Erosion processes ultimately redistribute the weathering products and new sediments are formed. When buried they undergo diagenesis to form the sedimentary rocks. Ultimately, these sedimentary rocks will be exposed and will themselves undergo weathering and form the parent materials of new soils. 

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