Application of secondary nutrients and micronutrients increases crop yields in sub-Saharan Africa
This article (PDF) in the journal Agronomy for Sustainable Development aims to determine the productivity increase of crops and nutrient use efficiency associated with secondary nutrients and micronutrients in sub-Sahara Africa. In this region, the main focus has been on macronutrients but there is emerging though scattered evidence of crop productivity limitations by the secondary and micronutrients. Elsewhere, widespread deficiencies of these nutrients are associated with stagnation of yields. This study used 757 yield data rows from field trials carried out in SSA between 1969 and 2013 in 14 countries. Results show that application of S and micronutrients resulted in a 25% yield increment for maize over what was achieved using the recommended fertilizer, which only contains macronutrients. Although there is high variability in crop response to S and micronutrients, the high proportions of cases with increased yield underscore the need for these nutrients. The authors conclude that S and micronutrients are holding back crop productivity especially on soils where response to macronutrients is low. More research is needed to unravel conditions under which application of S and micronutrients is beneficial to farmers. The results of this study highlight the need for policy support for the research on secondary nutrients, particularly S, and micronutrients and for blending them in currently used fertilizers. Further, decision support tools and training that can aid uptake of S and micronutrient technologies by farmers are needed.
This study is also discussed in this blog on the CIAT blog website. Additionally, The Food & Business Knowledge Platform is actively involved in this topic, and organised a workshop on “Micronutrient management for improving harvests, farmers’ incomes, human nutrition, and the environment” in 2016. Please find the workshop report here.