Concept:Contour ploughing is a soil conservation method that uses ridges across a slope to reduce erosion.
Explanation:Soil erosion happens when water or wind carries away the top layer of soil.
Ploughing along contour lines slows down the flow of rainwater.
Ridges formed across the slope trap water and allow it to soak into the ground.
This prevents the soil from being washed away.
Options A, C, and D all remove or damage vegetation cover, which accelerates erosion rather than controlling it.
Therefore, contour ploughing is the correct way to control soil erosion.
Answer:B. Contour ploughing