Ogbazghi, ZM, EH Tesfamariam, and JG Annandale. 2019. “Modelling Maize Grain Yield and Nitrate Leaching from Sludge-Amended Soils across Agro-Ecological Zones: A Case Study from South Africa”. Water SA 45 (4 October). https://doi.org/10.17159/wsa/2019.v45.i4.7548.