An investigation into soil fertility in two resource-poor farming communities in KwaZulu-Natal (South Africa)

Abstract

Low soil fertility is one of the major constraints affecting agriculture in Africa, a phenomenon that is also evident in fields of resource-poor farmers in KwaZulu-Natal. However, nutrient depletion status is field specific. This paper investigates the hypothesis that among KwaZulu-Natal resource-poor farmer's fields, the fields closer to the homestead are more intensively managed and that this differential management is reflected in the fertility status of these fields. In two communities, topsoil (0–15 cm) samples were taken from the ‘homefields’ as well as the ‘outfields’. Calcium, Mg, P, K, exchangeable acidity, pH, Mn, Zn, sample density and an estimate of organic carbon and clay content analyses were determined for all the samples. The median adjusted-P was 14 mg l⁻¹ in the ‘homefields’ and 4 mg l⁻¹ in the ‘outfields’ of Obonjaneni and 11 and 3 mg l⁻¹ respectively for ‘homefields’ and ‘outfields’ in the Valley of a Thousand Hills. Similar trends were observed for K. The acid saturation at Obonjaneni was 46% for ‘homefields’ and 73% for ‘outfields’. This study indicates the higher fertility status and better management of the ‘homefields’ in comparison to the ‘outfields’, and reflects the fact that two different management systems are being used in resource-poor farmer's fields as well as the necessity of sampling individual fields.