Afforestation is the planting of trees where trees had never existed while reafforestation means planting trees where the forest had been cleared. The planting of trees plays a big role in soil conservation.
Trees can be planted on homesteads, on the field, or on special tracts of land to form the forest. They can also be planted on embankments of terraces.
The following are roles of trees in soil conservation:
- They protect the soil below from raindrop erosion by reducing the force with which it falls on the ground.
- They provide shade and reduce the loss of moisture through evaporation.
- They act as windbreak hence reducing wind erosion.
- The roots of trees bind the soil particles together. Holding of soil particles by roots help to reduce soil erosion and washing away of nutrients by run off
- They reduce the speed of running water thus reducing its erosive power.
- The leaves of trees decay to supply humus to the soil which improves the infiltration rate of the soil. Also humus provided by decaying tree leaves provide much needed nutrients to vegetation and become food to micro organisms