Land-cover changes in South Africa 1911-1993

Abstract

The area under cultivation in South Africa more than tripled during the twentieth century, while plantation area increased more than tenfold. These land covers now constitute 12% and 1.5%, respectively, of the country's surface area. This paper describes the changes that have occurred in relation to the production and yields per hectare of major crops (maize, wheat, sorghum and sugar cane) and discusses the factors that contributed to the changes. Both domestic and global population growth partly underlie the increased demand for crop products over the past century. Increased production was initially achieved mainly by expanding the area under cultivation, and, from the 1960s onwards, principally through enhanced yields per hectare. In the latter period, nationally averaged productivity in a given year was related to fertilizer use, irrigation and the proportion of the country experiencing dry conditions. The crops grown and the yields per hectare differed significantly between the predominantly commercial, former white-owned areas and the mainly subsistence, former homeland areas. Independent estimates of historical cultivated area at the national level were derived from estimates of production and productivity per hectare, presenting a method that could be used to obtain improved historical land-cover estimates in data-poor countries.