Soil degradation is described as a decline in quality and condition of soil due to improper use or management. Degraded soil undermines the productive potential of land and reduces food production. Agricultural, trade and ecology experts regard soil as the cornerstone of food security and agricultural development. According to the World Map on Status of Human-Induced Soil Degradation, erosion is noted in South Africa and is largely attributed to prevailing agricultural practices. South Africa heavily depends on local agricultural production for food. Degradation has adversely affected and continues to ravage communal croplands, grazing fields, and settlement areas. Due to human influence, wind and water erosion are the major agents of soil degradation.
South Africa’s increase in population translates to an increase in demand for food and agricultural produce annually. Consequently, there is the increase in per capita consumption, bearing in mind that arable farms remain the same size. As a result, there is increased strain on agricultural land. According to statistics obtained from the Department of Agriculture, Forestry and Fisheries more than 60% of the country is under commercial farming whereas 10% is under cultivation. Increase in population leads to a high rate of development which in turn put greater stress on soils.
Farmers in South Africa have adopted agricultural intensification techniques, for example, intensive cropping patterns, excessive use of fertilizers and excessive irrigation, to maximize output due to increased demand for food. Intensification refers to an agricultural system that increases production with respect to units of input for example seeds, fertilizer, and labor. Degraded and under-productive soils may impair a county’s ability to feed its population. Degradation mostly occurs in the form of soil nutrient disorder, waterlogging or salinity.
It is not possible to immediately quantify the actual costs associated with land degradation since the country’s net agricultural income does not factor environmental costs. Costs associated with water treatment and dam sedimentation are estimated to be about $172 million. Other costs such as those associated with neutralizing effects of acidic rainfall run up to $2 million annually.
Soil erosion is an environmental phenomenon also affecting arable land in South Africa. Although it may occur as a natural phenomenon, in this modern age it is often influenced mostly by human factors. Soil erosion refers to the wearing off and displacement of the top soil; it is a slow process that may continue relatively unnoticed. It is considered a form of soil degradation and may at times occur at a fast rate causing depletion of the fertile upper layer of soil. Sheet and rill erosion occur slowly and are not very conspicuous, gully erosion, on the other hand, occurs fast and is very evident. Since gully erosion is visible, modern technology utilizing satellite imagery is in use to monitor and mitigate its causes. In Africa erosion threatens food and if not dealt with it could contribute to global warming. A report on monitoring soil erosion in South Africa shows that 70% of the country is affected by soil erosion in varying degrees.