Mechanisms for nutrient interactions from organic amendments and mineral fertilizer inputs under cropping systems: a review.

Food security issues continue to be a challenge in most parts of the globe, especially in sub-Saharan Africa (SSA). Several research attempts on addressing this issue have mainly been on nutrient replenishment using combined nutrient application of organic amendments and mineral fertilizer inputs. However, there is limited information available on the potential mechanisms underlying nutrient interactions associated with co-application of organic amendments and mineral fertilizers. Therefore, this review focuses on the mechanisms underlying crop nutrient interactions, with particular emphasis on improved nutrient synchrony, priming effect, general soil fertility improvement and balanced proportion of nutrients required by crops. Following a brief overview of the mechanisms, the review describes four common pre-determined nutrient ratios required by plants depending on its life cycle, environment and genotypic characteristics in order to attain the crop's maximum genetic potential. The review concludes with the need for future research to understudy mechanisms causing nutrient interaction under cropping systems, so as to apply nutrients at the most appropriate time to synchronize nutrient release with crop uptake, with the utmost goal of promoting sustainable crop production and enhancing food security.