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i) Besides planting of trees state any other three measures that can be used to control desertification.
ii) Explain how trees help in the conservation of the soil.

Answer Text:
i) - Controlling overgrazing
- Avoiding bush fires
- Controlling tree cutting
- Practicing appropriate methods of cultivation e.g.
planting cover crops, irrigation, mulching, terracing, contour farming.
ii) - Leaves & branches reduce the force of rain drops which would otherwise loosen and remove soil particles.
- Rate of infiltration of rain water into the soil is increased by vegetation cover thus reducing surface run off
- Tree roots which penetrate the soil help to carry surface moisture into the ground. This
allows the moisture to gradually percolate deeply
- Tree roots bind the soil particles together and therefore the soil cannot be easily carried away.
- Trees break the wind’s force.