What is soil erosion and how to combat it

It's estimated that one billion tons of valuable nutrients in topsoil are lost to erosion every year. In India, over 70% of cultivated land has been affected by erosion.

Also read: Losing ground

Soil erosion is the loss of topsoil, for which rain is the biggest cause. Water is about 800 times heavier than air and about as heavy as loose topsoil. A drop of rain hits the ground hard enough to dislodge the soil, which is then carried away by flowing water. Here's a guide on the process: