What are the methods of preventing or reducing soil erosion?

Concept: 

Preventive measures of soil disintegration are:

-Afforestation Planting more trees diminishes soil erosion.

-Contour ploughing The process of farming by keeping the lines of contour on the sloppy regions. Water distribution in the crops can be improved by keeping the contour lines. These lines decrease topsoil movement and avoid soil erosion. It is considered to be a method of sustainable agriculture.

-Soil cover is done by growing trees and crops that cover the soil which prevent weeding and regulate elimination of topsoil.

Hence, the correct answer is option D.