This study is based on the work of Hilmar Venter (FAO consultant). Other collaborators were Gert van der Linde, Fertilizer Society of South Africa (FSSA), Ms Leonè Joubert (FSSA) and Jan Schoeman, Agricultural Research Council, Institute for Soil, Climate and Water (ARC-ISCW).
The study benefited from the contributions of K. Isherwood (consultant FAO), J. Poulisse and T. van den Bergen (FAO).
The background photograph (maize) is from FAO Mediabase: FAO/17826/A. Conti. The sources of the other photographs are FAO Mediabase: FAO/20195/G. Diana (sunflower), FAO/22647/J. Spaull (grapes) and EcoPort (citrus).
