Sosibo, Nondumiso Z., Pardon Muchaonyerwa, Lientjie Visser, Annelie Barnard, Ernest Dube, and Toi J. Tsilo. 2017. “Soil Fertility Constraints and Yield Gaps of Irrigation Wheat in South Africa”. South African Journal of Science 113 (1/2):9. https://doi.org/10.17159/sajs.2017/20160141.