Opportunity for increasing the soil quality of non-arable and depleted soils in South Africa: A review

Abstract The improvement of food security strategies on highly degraded soils has become a major challenge for South Africa, as the need to secure food sources for the growing population under harsher climatic conditions. South Africa is one of the many water scarce countries and is label 30th driest country in the world. The ability of a soil to serve as a growth medium for plants is directly influenced by the chemical, physical, and biological parameters but most importantly the fertility of the soil, which is a prominent part of soil quality. Numerous methods exist to enhance and maintain soil quality including the application of fertilizers and the other includes the application of geological materials to the soil. Basalt (commonly referred to as rock dust) application as a soil amendment has been the focus of numerous long-term studies on soil fertility. The results of long-term application of rock dust have indicated a reduction in continuously applying additional amendment, resulting in more sustainable farming operations. When considering South Africa's relative scarcity of available agricultural land and harsh climatic conditions against the increasing demand placed on food production by a growing population combined with water scarcity, it becomes evident that it is necessary to search for new innovative methods to improve soil quality, which is deemed non-arable and/or depleted. The potential for basalt in re-mineralisation and application on non-arable soil in South Africa hold enormous benefits for the economy.