Maize-cowpea intercropping as an ecological intensification option for low input systems in sub-humid Zimbabwe: Productivity, biological N2-fixation and grain mineral content

Poor soil fertility and erratic rainfall constrain crop production in rain-fed smallholder farming systems sub-Saharan Africa. Integration of drought tolerant N2-fixing crops into maize-based cropping is a risk-averse strategy that also improves nitrogen cycling. A field experiment was carried out during the 2017/18 2018/19 seasons Goromonzi district Zimbabwe. The trials were established on 14 farms, two types (homefields outfields), with eight treatments from combination (maize cowpea monocrops or maize/cowpea intercrops) without fertilizer (+N; -N). implemented same plots for consecutive seasons. An improved variety landrace used. objectives to determine 1) productivity different under variable conditions, 2) N2-fixation when planted as intercrops, 3) mineral composition maize grains intercrops sole crops. Contrary expected results, properties not significantly (P > 0.05) between types. land equivalent ratios (LER) >1 both seasons, implying intercropping. Intercropping reduced nodulation active nodules, but total nodule weight, resulting similar proportion derived atmosphere (%Ndfa) grown monocrop intercropping maize. However, amount fixed due smaller biomass compared monocropping. Maize grain contents (Fe, Zn, Mn, Cu, Ca, Mg, P, K) affected by season only. We showed generally increases system productivity, addition substantial amounts being added through N2-fixation. an agronomic biofortification option these nutrient-depleted soils. Finally, annual variation quality can be larger than yield, potentially posing serious challenges human nutrition.