Aquaponics as a productive rehabilitation alternative in Mpumalanga Highveld coalfields
The Mpumalanga Highveld Region is commonly known for its coal mining activities, especially surface mines. South Africa is still reliant on coal as its main energy source. A dilemma identified is that most of the coal reserves in Mpumalanga are (or were) located below highly productive arable land formerly used for food production such as maize. With a growing energy demand, these valuable areas of land are being impacted negatively. The post-mining land is predominantly rehabilitated to a grazing land capability instead of the pre-mining arable land capability, hindering the production of crops on those areas when mining ceases. This adds to the food security threat which South Africa is currently facing. The National Development Plan 2030 indicated the intentions to diversify the national economy. It was identified that agricultural activities should be expanded to relieve the high levels of poverty in rural areas, and that sustainable agriculture should be the main focus. With the prevailing trends of surface coal mines expanding on available arable land, the realization of this goal might not be possible. This study looked at aquaponics as a possible environmental management alternative that will enhance the agricultural productivity of rehabilitated mine land. An experimental site located close to Middelburg and Emalahleni was used as the base for this study to determine the financial feasibility of such a venture. Five chosen mines within a 20km radius were investigated to understand their rehabilitation practices and to prove that the sites are rehabilitated to a grazing land standard. These sites were all identified as favourable for the initiation of aquaponics. The two post-mining land use alternatives were compared with one another to understand what the benefits and constraints are. The economic driver was a main focus, followed with a brief overview of environmental and social aspects that can be kept in mind when these land uses are established.