Long-term no-tillage enhanced maize yield and potassium use efficiency under spring drought year

Tillage is an important management tool for tackling and promoting water conservation and improving crop yield. As one of the important nutrients in plant growth, K is involved in important processes such as osmoregulation, photosynthesis and metabolite transport, and plays a particularly critical role in improving crop yield and quality. In the long-term positioning platform of the tillage method, a 2-yr field experiment was conducted in 2019-2020 in maize (Zea mays L.) Three tillage methods: conventional tillage (CT), subsoil tillage (ST), and no-tillage (NT) and two planting densities 6×104 (D1) and 9×104 plants ha-1 (D2) were set up in the experiment. The results showed that yield and K translocation efficiency (KTE) were significantly higher in NT than in CT at D1 (by 4.7% and 12.2%) and D2 (by 14.0% and 13.9%), respectively. At maturity stage in 2019, population DM accumulation after silking (DMA) was significantly higher in NT (by 11.0% and 16.9%) than in CT at D1 and D2. Correlation analysis revealed that yield was significantly positive correlated with ears (r = 0.57***) and DMA (r = 0.64***). Potassium translocation and K harvest index were positively correlated with KTE. Under spring drought year, the long-term no-tillage had a significant yield increase, mainly through the increase in 1000-kernel weight. The increase in K efficiency was mainly through the influence of DM accumulation and distribution, and K accumulation in grain.