Maize–legume systems under conservation agriculture

AbstractSoil fertility depletion due to land degradation and poor cropping diversity have resulted in poor crop yield in sub‐Saharan Africa. On‐farm experiments were conducted to determine the effects of conservation agriculture (CA)‐based maize (Zea mays L.)–legume cropping systems and conventional tillage (CT) on soil properties and yield of maize. The experiments were laid out in a randomized complete block design with three replications. The experiments were continued for 3 yr from 2012 to 2014. The treatments were: CT with monoculture maize (CT‐M), CA with monoculture maize (CA‐M), CA‐based maize–common bean (Phaseolus vulgaris L.) intercropping (CA‐M+CB), CA‐based maize–cowpea (Vigna unguiculata L.) intercropping (CA‐M+CP) and CA‐based maize–common bean rotation (CA‐M–CB).Weed infestation in CA‐based maize–legume cropping systems reduced over the years. Application of CA‐based maize–legume cropping systems increased soil organic matter, total nitrogen, available phosphorus (Ava.P), and soil water infiltration rate by 37, 54, 12.3, and 327%, respectively, over CT‐M. Maize grain yield increased by 54% in CA‐M–CB over CT. The highest production efficiency was obtained from CA‐M–CB. In conclusion, CA‐M–CB followed by CA‐based maize–legume intercropping were the best soil management practices as elucidated in higher soil fertility and stable yield. However, future research on CA‐based cropping systems should be executed under various agro‐ecologies and crop types.