Describe the reasons for soil degradation.

The United Nations Environment Program has defined soil degradation as the decline in the fertility of soil or its ability to produce future crops because of human actions. This process occurs when people overuse or misuse soil, and it has both natural and socio-economic factors. Some of the factors that lead to soil degradation are the following:

• Physical factors: water or wind erosion, resulting in the loss of the top layer of soil.


• Chemical factors: loss of nutrients or processes leading to toxicity, such as acidity or salinization. Salinity can be caused by poor irrigation practices that upset the normal water table. 


• Biological factors: these factors reduce micronutrients, making soil less fertile. This process can be caused by poor fertilizers or high-yielding crops. 


• Other causes include over cultivation of land; poor farming practices such as mono-culture or overuse or misuse of fertilizers; overgrazing; over irrigation; and mining.

It is estimated that about 22% of the Earth's land is currently degraded, and this statistic is much higher in countries such as India.