Soil erosion is a natural process of excessive influence of water and wind on the upper fertile layer. It's aggravated by wrong human agricultural activity (destruction of vegetative cover by domestic animals or deforestation). Possible consequences of erosion vary from soil’s depletion (degradation) to destruction (desertification). From this article, you’ll find out the 4 main causes of erosion in Nigeria.
What are the causes of erosion?
Among the situations that strongly influence the occurrence of erosion are:
- degree of vegetation covering the land;
- type of soil, its composition, agro-technical condition;
- agricultural activity of people.
Let us dwell on each of these factors.
Rich vegetation weakens the impact of rainfall and therefore protects the soil from destruction. This increases the moisture capacity and rainwater retention. The roots of the plants bind the soil particles, leading to a stronger structure and, consequently, prevent the washing away of the soil.
The turf layer is also moistened. During periods of intense rains, it retains a large amount of water, thereby delaying its runoff and preventing erosion.The protective role of vegetation from wind influence is well known. The creation of forests and trees helps to control erosion. When the soil is properly covered with vegetation, water and wind erosion is less likely to occur.
2. The climate
Climatic conditions are among the causes of erosion processes. The more moisture drops on the soil in the form of heavy rains, the more water erosion occurs. Conversly, the hotter and drier the climate is and the presence of strong winds, the stronger the likelihood of wind erosion.
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Climatic conditions is strongly influenced by geological factor. Obviously, if there are large catchment area and the rock or soil is steep, water erosion manifests itself quite noticeably. On the contrary, on a leveled territory with deep rocks and a weak vegetation cover, wind erosion can be quite strong.
3. Soil condition
The condition of the soil, its physical and chemical properties can affect the occurrence of erosion. Soil structure can be divided into structural and structureless.
Structural soils absorb water well. Therefore they will hardly be subject to erosion. They are also more stable against gusts of wind than atomized and structureless soils.
The most stable soils are the humus. The dry semi-desert and desert areas are subjected to the strong wind which results in the upper layer being sprayed.
Soil composition is very important when it comes to the prevention of soil. Light soils (sandy, sandy loam, loamy) are not washed away quite easily due to water capacity. But they are very much prone to wind erosion. Clay soils, depending on the structural state, react differently to erosion.
Many researches have shown that the more particles with a diameter of 0,01-0,05 mm the soil contains, the more easily it is washed away by water. Therefore, forest species should be considered the most flexible.
Comparing resistance of different layers against the erosive action of water, we must draw the following conclusion: the uppermost humus layer is the most stable, the lower layers are more pliable. Therefore, the upper soil is important not only because it has high fertility but also because it is more resistant to erosion. If this layer is affected and washed away, then the malicious process will sharply accelerate.
4. Agricultural activity of people
The cultivation of certain types of plants contributes to an increased chance of soil erosion. Arable crops, for instance, intensifies this phenomenon.
Wrapping the arable layer on slope areas may lead to erosion. It causes soil’s dispersion, destruction, and stronger likelihood of both wind and water erosion. When heavy tractors and other agricultural machinery passes through the field, the soil becomes heavily compacted. Its water permeability decreases. The soil can then be easily washed away.
A land highly saturated with arable crops, high intensity of mechanical tillage, lack of soil-protecting vegetation (perennial grasses) – all these factors contribute to erosion.
Now you know what soil erosion is and the factors that contribute to its occurrence. We hope that you found this information interesting.