Soil is the uppermost layer of earth’s surface which supports all forms of life. It is in the soil that all plants have their roots and from which they absorb life-sustaining moisture and nutrients.
Man, in turn, feeds directly upon these plants or upon plant eating animals. Thus, virtually all terrestrial life ultimately derives from the soil. If a nation’s soil resources are fertile and abundant, in like measure will that state have vigour and stability? When this resource is exhausted because of mounting demands of a swelling population or long mismanagement, the nation’s survival is in jeopardy. Some authorities believe that one of the causes of the decline of the Roman Empire was deterioration of soils. The loss of soil, either by natural process or by mismanagement, is harmful not only for agricultural development but to the whole ecosystem, therefore, its conservation has now become a matter of grave concern.
The main reason for the loss of soil is soil erosion which is of four types as under:
(i) Normal soil erosion,
(ii) Soil erosion by water
(iii) Wind soil erosion
(iv) Accelerated soil erosion
Normal soil erosion is a natural and a very slow process, therefore, not harmful; rather it helps in soil formation. Soil erosion by water is quite widespread and a main reason of soil loss and loss of fertility. Water soil erosion is of four types, viz., sheet erosion, rill erosion, gully erosion and riparian erosion. The third agent of soil erosion is the wind. Winds are more effective in arid and semi-arid regions. While the accelerated soil erosion is done by human activities, which accelerate the process of soil erosion by deforestation, grazing, mining, defective agricultural practices, etc., landslide and leaching is also a reason of soil loss. The problem for soil loss now has become a worldwide problem and its conservation is necessary.
