The environmental effects of sugarcane expansion: A case study of changes in land and water use in southern Africa

Abstract

Sugarcane is often portrayed as one of the most environmentally sustainable food and energy crops, yet evidence of the crop's social and environmental impacts in Africa's growing sugarcane industry remains scarce. The land cover replaced by cane and subsequent land use practices play important roles in shaping the environmental impacts of expansion. Land cover change can be both direct and indirect and land ownership is key in shaping socioeconomic impacts, yet these have not been systematically documented in an area experiencing cane expansion in Africa. This paper addresses these gaps through an analysis of land use changes and hydrological impacts associated with the 2006 to 2012 expansion of Zambia Sugar in Mazabuka, Zambia. Methods included semi-structured interviews with Zambia Sugar and outgrowers, remote sensing of land cover to quantify the types of land conversion, and hydrological analysis of impacts on regional crop water use and the Kafue River. The bulk of the expansion area as reported by Zambia Sugar (62%) converted low-water using shrublands to sugarcane, increasing total consumptive use of irrigation water by cane in Mazabuka to 13-16% of the 25% probability monthly mean low flow in the Kafue River. Commercial-scale growers represented 94% of the expansion area, calling into question claims about smallholder inclusion.