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Grade 4 | Science | Soil, Our Environment, Olympiad, CBSE, ICSE, Maths Olympiad, Science Olympiad, English Olympiad
Topmost layer of soil in which plants grow is called soil. It is generally black or brown in color. It consists of organic matter, clay, sand, silt and rock particles. It also contains water and air. Soil is very important as it supports plants and other life forms.
Layers of soil
Soil takes several years to form. The soil is formed by weathering of rocks.
Big rocks are broken into small pieces over time with the effect of wind, sun and water. This process is called weathering.
Gradual wearing away or washing away of top layer of soil is called soil erosion. Physical forces of wind and water are primary causes of soil erosion. Trees help in avoiding soil erosion as their roots firmly hold the soil. Deforestation is largely responsible for soil erosion.
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