Soil fertility management for groundnut in the lowveld of Mpumalanga and north coastal plain of KwaZulu-Natal provinces of South Africa

Abstract

Smallholder groundnut production contributes substantially to food security in Mpumalanga Lowveld (MLV) and in Manguzi, the northern coastal plain (NCP) of KwaZulu Natal (KZN), both of which are dominated by infertile structureless sandy soils. A study was conducted to obtain information on the chemical properties of the soils to guide fertilizer management for optimizing groundnut production on these soils. Soil samples were collected from representative sites in  MLV and NCP, and analysed for pH, calcium (Ca), magnesium (Mg), potassium (K), phosphorous (P), zinc (Zn) and manganese (Mn) in the peg-zone (0-10 cm depth), root zone (10-40 cm depth) and subsoil (40-60 cm depth). The soils were largely acidic, with pH mostly falling below 5.5. The basic cation concentrations were generally low, and so were Zn and Mn concentrations. Nonetheless, with the exception of P and Mn, the soil concentrations of the other nutrients analysed were within ranges considered adequate for vegetative and reproductive growth of groundnut, though Zn was marginally so. General fertility management recommendations to inform agricultural extension are provided for groundnut production on the sandy soils based on the chemical analyses of the soils.