Conserving Water is not a cause of desertification.

444 acres

The statement that best describes what is occurring in the land surrounding the Sahara Desert is: Desertification is increasing, and the desert is expanding.

‘Climatic variations’ and ‘Human activities’ can be regarded as the two main causes of desertification. removal of the natural vegetation cover（by taking too much fuel wood）, agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity.

The main causes for desertification are overcultivation of poor soils, over grazing by animals, excessive cutting of fuelwood and inappropriate irrigation practises resulting in salinization. Among them overgrazing is the most important factor as it causes maximum effect.

• Reduce Tillage. Reducing tillage allows crops to remain in the soil rather than being plowed at the end of a season.
• Contour Farming.
• Cover Crops.
• Windbreaks.

Planting Vegetation as ground cover: Farmers plant trees and grass to cover and bind the soil. Plants prevent wind and water erosion by covering the soil and binding the soil with their roots. The best choice of plants to prevent soil erosion are herbs, wild flowers and small trees.

You can reduce soil erosion by:

• Maintaining a healthy, perennial plant cover.
• Mulching.
• Planting a cover crop – such as winter rye in vegetable gardens.
• Placing crushed stone, wood chips, and other similar materials in heavily used areas where vegetation is hard to establish and maintain.

Erosion Control Methods

1. Baffles or barriers are obstruction devices that slow down or divert water from flowing directly downhill.
2. Riprap is rough, loose stone (at least 6-8 inches wide each).
3. Terraces stair-step up the slope.
4. Plants can help control slopes.

Following steps are taken to control the soil erosion in hilly areas: (i) Contour ploughing: this refers to ploughing along contour lines. (ii) Terrace farming: construction of steps along the hilly areas by cutting the rock layers to reduce the flow of rivers. (iii) Plugging of gullies to prevent gully erosion.

The following measures can help to solve the problem of land degradation in hilly and desert areas: (i) Afforestation over deforested areas. (ii) Proper management of grazing on permanent pastures. (iii) In areas where, desertification has taken place, growing thorny bushes.

Contour ploughing: This soil conservation method is useful on the slope of hills where the ploughing of the field is done parallel to the contour of hill slope forming a natural barrier for the water to flow down the slope. The practice is done to grow crops on the hilly areas and also for conserving the soil.