Decade-long conservation tillage enhances crop productivity by improving soil health in the Northeast China Plain

Conservation tillage has emerged as a transformative agricultural practice with the potential to reconcile soil health restoration with sustainable crop productivity, yet its long-term effects and underlying yield-enhancing mechanisms remain unclear. Four tillage practices (NT: No tillage, MT: Mulch tillage, ST: Strip tillage, CT: Conventional tillage) were implemented from 2014 to 2024 to investigate the mechanisms on how conservation tillage reshapes soil function and enhances crop productivity. The results showed that conservation tillage practices (NT, MT, ST) significantly improved soil physical properties (e.g., temperature regulation, moisture retention, and structural stability). Changes in soil physical properties benefit to the improvement of soil organic carbon (SOC), total nitrogen (TN), available nutrients, microbial biomass and enzymatic activities (urease, β-glucosidase, acid phosphatase, etc.). NT exhibiting the most pronounced increment (SOC by 4.62%-25.58%, key enzyme activities by 20.01%-152.99%). Compared with CT, conservation tillage systems significantly increased maize yield by 3.06%-23.73% and SQI by 156.55%-499.42%, with NT and MT demonstrating superior performance. The SQI was strongly correlated with yield (R²= 0.798, P < 0.01), indicating that conservation tillage has advantages in maintaining soil health and productivity. The findings offer empirical evidence for the popularization of conservation tillagete chnologies in the black soil region of Northeast China and other similar agro-ecological zones globally, and provide scientific support for formulating agricultural sustainable development policies that balance soil health protection and grain production capacity improvement.