Human activities like over-cultivation, unrestricted grazing, deforestation and poor irrigation practices, results in arid patches of land. When large barren patches extend and meet over time, a desert is created. Irrigation without proper drainage of water leads to waterlogging in the soil. Waterlogging draws salt to the surface of the soil. The salt then is deposited as a thin crust on the land surface or starts collecting at the roots of the plants. This increased salt content is inimical to the growth of crops and is extremely damaging to agriculture.