Maize fertilizer research over the last 25 years – an overview

Abstract

Maize yield as well as fertilizer practices have changed over the last 25 years. Average maize yield for South Africa increased from approximately 2.3 tons ha-1 in the early 1980s to approximately 3.5 tons ha-1 in recent years. The early 1970s to the middle 1990s can be seen as a "boom period" for maize fertilizer research in South Africa. Up until 1995, fertilizer research was grouped in specific projects with clearly defined goals and a definite direction. Research was to a large extent pro-active. This research approach is no longer clearly visible and it has become largely reactive, with emphasis on ad hoc problem solving instead of goal oriented research. Such an ad hoc approach can cost us dearly because there will be no real research progress. This paper also gives an overview of research over the last 25 years on soil acidity, macronutrients (N, P and K), secondary nutrients (S, Ca and Mg), micronutrients (Zn) and other contributions (long-term trials and fertilizer placement). The reduction in maize fertilizer research is of concern when seen against the background of the regional and continental importance of maize. Well planned nutrition research can ensure food security and nutrition security both locally and in other parts of the continent, provided there are clear goals and direction, adequate funding, proper management and coordination. Fragmented, ad hoc trials will not create prosperity for all in the region.