17 Jun Combating Desertification and Drought in Africa
The World Day to Combat Desertification and Drought is observed on 17 June each year to promote public awareness of international efforts to combat desertification. Desertification is an increasing ecological problem.
The problem in Africa
Africa is the continent most affected by desertification. One-third of Africa’s drylands are largely uninhabited arid deserts, while the remaining two-thirds support two-thirds of the continent’s burgeoning human population. As Africa’s population increases, the productivity of the land supporting this population declines. Some one-fifth of the irrigated cropland, three-fifths of the rain-fed cropland, and three-fourths of the rangeland have been at least moderately harmed by desertification.
Solutions to desertification
- Irrigation improvements can inhibit water loss from evaporation and prevent salt accumulation. This technique involves changes in the design of irrigation systems to prevent water from pooling or evaporating easily from the soil.
- Cover crops, which prevent soil erosion from wind and water. They can also reduce the local effects of drought. On larger scales, plant cover can help maintain normal rainfall patterns. Cover crops may be perennials or fast-growing annuals.
- Crop rotation involves the alternation of different crops on the same plot of land over different growing seasons. This technique can help maintain the productivity of the soil by replenishing critical nutrients removed during harvesting.
- Rotational grazing is the process of limiting the grazing pressure of livestock in a given area. Livestock is frequently moved to new grazing areas before they cause permanent damage to the plants and soil of any one area.
- Terracing involves the creation of multiple levels of flat ground that appear as long steps cut into hillsides. The technique slows the pace of runoff, which reduces soil erosion and retards overall water loss.
- Contour bunding (or contour bundling) involves the placement of lines of stones along with the natural rises of a landscape, and contour farming. These techniques help to capture and hold rainfall before it can become runoff. They also inhibit wind erosion by keeping the soil heavy and moist.
- Windbreaks involve the establishment of lines of fast-growing trees planted at right angles to the prevailing surface winds. They are primarily used to slow wind-driven soil erosion but may be used to inhibit the encroachment of sand dunes.
- Charcoal conversion improvements include the use of steel or mud kilns or high-pressure compacting equipment to press the wood and other plant residues into briquettes. Conversion improvements retain a greater fraction of the heating potential of fuelwood.