Crop Yield Responses to No-Tillage Versus Rotary Tillage Across China: Drivers and Spatial Heterogeneity

Rotary tillage (RT) is the predominant soil management practice in China’s croplands, but long-term intensive use may compromise soil structure. No-tillage (NT) is promoted as an alternative, yet whether it maintains productivity relative to RT is uncertain. We synthesized 383 paired NT–RT comparisons from 94 publications across China with a multilevel meta-analysis clustered by publication. Relative to RT, NT reduced grain yield by 4.28% (95% CI −6.13% to −2.39%), an estimate that remained between −3.90% and −4.94% across six weighting and aggregation schemes. The reduction was associated with a 5.22% decline in spike number, partly offset by a small and non-significant increase in grain number per spike (+2.17%). Bulk density increased by 3.44%, whereas soil organic carbon (+4.62%) and total nitrogen (+3.45%) did not change significantly. Nitrogen application rate, available potassium and NT duration carried the highest cumulative Akaike weights and were the dominant predictors of yield responses. Structural equation modelling indicated that increased bulk density was negatively associated with 1000-grain weight (β = −0.21), whereas nutrient status was positively associated with grain filling (β = 0.92); these are associations, not identified causal mechanisms. Machine learning was integrated with georeferenced soil and climate data to conduct national-scale spatial prediction of crop-yield responses to NT relative to RT. Across the six major agricultural regions, the predicted yield response to NT relative to RT for all crops was least negative in Northeast China (−0.88%) and most negative in North China (−4.02%).The resulting spatial predictions revealed substantial crop-specific and regional variation in yield responses across China’s croplands. NT therefore carries a consistent, context-dependent yield cost in China, and soil physical degradation accompanies rather than offsets it.