Evaluation of maize/peanut intercropping effects on microbial assembly, root exudates and peanut nitrogen uptake

Legume/cereal intercropping has been widely studied within ecosystem function, owing to its overyield potential, predominantly by dinitrogen (N2) fixation. In our 2-year peanut/maize intercropping field experiment, land equivalent ratio (LER) showed an average yield-increase by 41.48%. Performance index of intercropped peanut (IP) functional leaves exhibited significant improvement (2.02-fold). Moreover, IP increased dry nodule weight by 58.82% as compared to mono-cropped. Also, the ratio of nodules to aboveground biomass in IP reduced by 65.8%. In pot experiment, higher urease activity was found in rhizosphere (22.73%). The abundance of Rhizobium and ni integral H gene in the rhizosphere of IP were significantly enhanced by 71.91% and 208%, respectively. To analyze root exudates, we performed hydroponic coculture, the proportion of total isoflavonoids in peanut root exudates were increased distinctly by 22.4%. Our findings certainly helped in filling one the information gaps, that how intercropping increases nitrogen fixation in rhizosphere. Lastly, it can further facilitate to understand functional significance of intercropping system for agricultural ecological sustainability and efficient resource utilization.

Automated summary

Legume/cereal intercropping increases yield and improves functional leaves and nodule characteristics through nitrogen fixation. Intercropping also enhances the abundance of nitrogen fixation-related genes and the proportion of isoflavonoids in root exudates.