1. South African Sugarcane Research Institute, Mount Edgecombe, South Africa
2. Department of Soil, Crop and Climate Sciences, University of the Free State, Bloemfontein, South Africa
3. Faculty of Natural and Agricultural Sciences, University of Pretoria Department of Soil, Pretoria, South Africa
4. ARC-Institute for Soil, Climate and Water, Pretoria, South Africa
5. ARC-Institute for Soil, Climate and Water, Bloemfontein, South Africa
6. Department of Agriculture, Forestry and Fisheries, Pretoria, South Africa