No-tillage with total green manure incorporation: A better strategy to higher maize yield and nitrogen uptake in arid irrigation areas

Abstract

The efficacy of integrating green manure in arid irrigation regions to enhance maize yield and nitrogen (N) uptake efficiency has been extensively explored. However, limited research has delineated the contribution of green manure N versus soil N on crop N utilization efficiency. This study integrated field experiments with micro-plot experiments to examine green manure (common vetch) management practices for achieving high maize yield and N uptake. In a micro-plot experiment, 15N technology was utilized to label green manure crops. Five treatments were applied in the research methodology: conventional tillage without green manure as the control (CT); tillage with total green manure incorporation (TG); no-tillage with total green manure mulching (NTG); tillage with only root incorporation (T); and no-tillage with removal of above-ground green manure (NT). The results in the micro-plot experiment were the same in the field, and both demonstrated that the utilization of green manure led to a substantial increase in maize yield and nitrogen uptake efficiency (NUPE) compared to conventional tillage (CT). In particular, under NTG, N uptake by maize from green manure was higher than NT and T, accounting for 59.1% of maize N uptake. Furthermore, the application of NTG boosted the NUPE of soil N in maize to 50.7%, which is higher than TG by 5.5%. Meanwhile, it decreased the proportion of soil N in the maize. The difference between NTG and TG was primarily shown in the maize grains. For N transport in the soil, NTG decreased N loss while increasing soil N retention. Also, it facilitated the mineralization of soil organic N before the flowering stage. In conclusion, the adoption of no-tillage with total green manure mulching not only increased N uptake both from green manure and the soil but also decreased the proportion of soil-derived N in maize.