Soil erosion: Among the agents, water is considered as the main cause of soil erosion. Main agents of soil erosion are (1) Water, (2) Wind, (3) Waves and (4) Glaciers Removal of the top layer of soil by various means, which include both natural events and human activities, is called as soil erosion.
Decline of soil fertility: Soil fertility is mostly affected in the states of Punjab, Haryana, and U.P. It is a condition when the soil is not giving enough production even though adequate irrigation and nutrients are supplied.
Water logging :If there is no proper drainage system in the land, the land will become waterlogged. This results in the saturation of crops. The normal circulation of air will not be possible due to water logging and the amount of oxygen in the soil will decline.
Salinity: Soil will become saline or alkaline in low rainfall areas. Rajasthan is an example. When the sea water enters the land, the soil becomes saline. The presence of calcium carbonate beneath (kankar) the soil will act as impermeable to water and water gets logged as happened in Indira Gandhi canal regions of Rajasthan. If the soil contains salt content, it will spread to the whole land due to this.
