Question

Explain how afforestation helps in soil conservation.

Answer 1

1. Roots bind and hold soil particles together, preventing easy removal by running water or wind.
2. Plant canopy and undergrowth reduce the impact of raindrops on the soil surface, lowering surface detachment and sheet erosion.
3. Vegetation slows down surface runoff (acts as a natural obstruction), reducing runoff velocity and allowing more water to percolate into the soil rather than carrying soil away.
4. Trees act as windbreaks (shelterbelts), reducing wind speed at ground level and thus limiting wind erosion of topsoil.
5. Fallen leaves and plant litter form a protective mulch layer that shields topsoil from erosion, conserves moisture, and,after decomposition,adds humus to improve soil fertility.
6. Planting trees along field edges, steep slopes, and gullies (shelterbelts/contour planting) helps plug gullies, stabilise slopes and protect agricultural land from both water and wind erosion.
7. By increasing infiltration and groundwater recharge, afforestation can help raise the water table and maintain soil moisture, further reducing susceptibility to erosion and drought.
8. Afforestation reduces sediment load entering rivers (less soil carried downstream), which helps prevent riverbed silting and reduces flood risk in lower plains.