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#### • agriculture soil erosion

From Wikipedia

Erosion control

Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development and construction. Effective erosion controls are important techniques in preventing water pollution and soil loss.

## Introduction

Erosion controls are used in natural areas, agricultural settings or urban environments. In urban areas erosion controls are often part of stormwater runoff management programs required by local governments. The controls often involve the creation of a physical barrier, such as vegetation or rock, to absorb some of the energy of the wind or water that is causing the erosion. On construction sites they are often implemented in conjunction with sediment controls such as sediment basins and silt fences.

## Examples

Examples of erosion control methods include:

## Mathematical modeling

Since the 1920s and 1930s scientists have been creating mathematical models for understanding the mechanisms of soil erosion and resulting sediment surface runoff, including an early paper by Albert Einstein applying Baer's law. These models have addressed both gully and sheet erosion. Earliest models were a simple set of linked equations which could be employed by manual calculation. By the 1970s the models had expanded to complex computer models addressing nonpoint source pollution with thousands of lines of computer code. The more complex models were able to address nuances in micrometerology, soil particle size distributions and micro-terrain variation.

From Encyclopedia

soil

soil surface layer of the earth, composed of fine rock material disintegrated by geological processes; and humus , the organic remains of decomposed vegetation. In agriculture , soil is the medium that supports crop plants, both physically and biologically. Soil may be from a few inches to several feet thick. Components and Structure The inorganic fraction of soil may include various sizes and shapes of rocks and minerals; in order of increasing size these are termed clay , silt , sand , gravel , and stone. Coarser soils have lower capacity to retain organic plant nutrients, gases, and water, which are essential for plants. Soils with higher clay content, which tend to retain these substances, are therefore usually better suited for agriculture. In most soils, clay and organic particles aggregate into plates, blocks, prisms, or granules. The arrangement of particles, known as soil structure, largely determines the soil's pore space and density, which translates into its capacity to hold air and water. Organic matter consists of decomposed plant and animal material and living plant roots. Microorganisms, living in the organic portion of soil, perform the essential function of decomposing plant and animal matter, releasing nutrients to be used by growing plants. Besides organic matter, soil is largely composed of elements and compounds of silicon, aluminum, iron, oxygen, and, in smaller quantities, calcium, magnesium, sodium, and potassium. Factors determining the nature of soil are vegetation type, climate, and parent rock material; geographic relief and the geological age of the developing soil are also factors. Acidic soils occur in humid regions because alkaline minerals are leached downward: alkaline soils occur in dry regions because alkaline salts remain concentrated near the surface. Geologically young soils resemble their parent material more than older soils, which have been altered over time by climate and vegetation. For advice and information on soils, consult state agricultural experiment stations and their publications. Undisturbed soils tend to form layers, called horizons, roughly parallel to the surface. The Russian system of soil classification, from which most others derive, is based on the distinctive horizons of the soil profile. The A horizon, the surface layer, contains most of the humus. The B horizon contains inorganic compounds formed by decomposition of organic material, a process known as mineralization; the material is brought to the B layer by the downward leaching action of water. The lowest soil layer, the C horizon, represents the weathered mineral parent substance. Soil Fertility and Conservation Soil fertilityâ€”the ability to support plant growthâ€”depends on various factors, including the soil's structure or texture; its chemical composition, esp. its content of plant nutrients; its supply of water; and its temperature. Agriculture necessarily lowers soil fertility by removing soil nutrients incorporated in the harvested crops. Cultivation, especially with heavy machinery, can degrade soil structure. Agricultural soils are also vulnerable to mismanagement. Exposure of soils to wind and rain during cultivation encourages erosion of the fertile surface. Excessive cropping or grazing can depress soil-nutrient levels and degrade soil structure. Soil conservation techniques have been developed to address the range of soil management issues. Various methods of cultivation conserve soil fertility (see cover crop ; rotation of crops ). Minimum-tillage systems, often entailing herbicide use, avoid erosion and maintain soil structure. Soil fertility and agricultural productivity can also be improved, restored, and maintained by the correct use of fertilizer , either organic, such as manure , or inorganic, and other soil amendments. Organic matter can be added to improve soil structure. Soil acidity can be decreased by addition of calcium carbonate or increased by addition of sulfuric acid. Bibliography See F. R. Steiner, Soil Conservation in the United States (1990); M. Alexander, Introduction to Soil Microbiology (2d ed. 1991); E. J. Plaster, Soil Science and Management (2d ed. 1991); publications of the U.S. Soil Conservation Service.

Question:how is it caused? wat can we do to prevent it? how can i write a creative story about soil erosion? any tips?

Answers:Erosion is caused mainly by inadequate handling of the ground (but it is a natural process). It depends on the composition of the soil (more sands, more erosion; more clay, less erosion). To prevent it, ' the main one is to keep the ground covered '. The covering protects against the impact of rain, as an umbrella, preventing the torrent formation. It is important to reduce the speed of the draining of the water and its impact in the ground. If the covering of the ground well will be made, with more than 30% of the covered surface, the risks of the erosion diminishes more than in 60%. The direct plantation is a good technique to be used too.

Question:please give me a good answer that is to the point. its urgent

Answers:Afforestation is the process of establishing a forest on land that is not a forest, or has not been a forest for a long time by planting trees or their seeds. Soil erosion is when the soil is blown away by the wind or washed away by the rain. Roots of trees/plants hold the soil. Thus, when more trees are planted their roots don't allow the soil to be blown or washed away and prevent soil erosion.