Soil is a complex entity and is represented by the land surface and the operative soil profile depth. It functions physically, chemically as well as biologically. Therefore, its health and also its utility for various land uses has to be judged from these three angles. The extensive limitation of Indian soils is their low inherent fertility level through exhaustion over centuries. In addition, there has been a steady depletion of supporting vegetation for regeneration of the soil fertility through organic recycling and transportation of nutrients from lower reaches to productive top layers. Due to acute shortage of fuel and fodder, even agricultural crop residues are not incorporated into the soil. Cowdung is used mostly as fuel, while forest humus is simply not there, with deforestation going unabated.
Another limitation is extensive water stress, due to extended dry season and drought. This is because supply of water is limited in time, whereas demand for various purposes is stretched throughout the year. Though India, is fortunate in terms of average annual rainfall, larger parts of India receive low to very low rainfall. In places receiving heavy or medium rainfall, much of it flows out and causes problems of flood elsewhere. Since water becomes available to users like men, animals, and plants only after it has routed through land surface and soil profile. Land and water cycle have a close relationship. This relationship becomes all the more important because surface runoff and floods are some of the main causes of nutrient depletion and loss of productivity. Now, we will study about soil erosion which is one of the phenomena that causes degradation of the soil.