Effects of maize-soybean rotation and plant residue return on maize yield and soil microbial communities

Abstract

Background and aims The practice of returning corn stalks back to fields is widely implemented in maize cropping systems, but its impacts on maize yield is inconsistent due to different methods employed. We hypothesized soybean-maize rotation system with returning crop stalks to enhance soil health and maize yield. Methods A field trial was carried out from 2013 to 2018, comparing a soybean-maize rotation system with sole maize cultivation. Soil physicochemical properties, agronomic traits of maize and soil microbial community were determined. Results Maize yield and ear diameter were significantly higher in the rotational cropping system in 2018, compared to monocropping. Over the years, organic matter contents remained stable in the soil under rotational cropping but decreased in the monocropping soil. Different cropping systems also led to shifts in soil microbial communities: rotational cropping augmented fungal diversity, though the overall compositions of bacterial and fungal communities did not significantly differ between the two cropping systems. The proliferation and beneficial impact of functional microorganisms involved in crop residue decomposition, biological control of soil-borne disease, nutrient metabolism, and nutrient uptake were closely related to the improvement of maize yield and soil nutrition within the rotational cropping system. Conclusions Maize-soybean rotation and plant residue return sustained increased maize yield and organic matter contents of soil. The overall effect of the soil microbiome exhibited a positive association with both soil health and maize yield. This study highlights the potential of combining crop residue returns with crop rotation in bolstering soil health and fostering increased maize yield.