Enhancing crop yield and resource use efficiency through ridge tillage: A global meta-analysis across climatic and soil gradients

Ridge tillage (RT) is an adaptive and increasingly adopted conservation farming practice aimed at improving productivity and resource use efficiency. However, a comprehensive understanding of its integrated effects and underlying mechanisms across diverse climatic, soil, and management conditions remains limited. We conducted a global meta-analysis of 1579 observations from 65 peer-reviewed studies to evaluate the effects of RT on microclimatic, evapotranspiration (ET), crop yield, water use efficiency (WUE), radiation use efficiency (RUE), and thermal use efficiency (TUE). In addition, we quantified the relative contributions of climatic, soil, and managerial drivers. Microclimate analysis showed that RT reduced soil temperature (−2.7%), increased canopy CO₂ concentration (+1.4%) and wind speed (+30.3%), while slightly decreasing canopy humidity. These microclimatic improvements contributed to enhanced WUE, RUE, and TUE by 11.9%, 17.0%, and 14.3%, respectively. Ultimately, RT led to a significant yield increase of 14.9% without affecting ET. Yield increases were more pronounced in high-altitude (≥1500 m, +26.9%) and warmer (≥18 °C, +24.3%) regions. Greater yield gains were also observed in soils with medium to low nutrient levels and moderate bulk density. Among management practices, a < 1 ridge-to-furrow ratio and the application of film mulching on ridges further enhanced RT benefits. Decision tree analysis identified soil characteristics as the dominant factors influencing both yield and ET responses (45.5% and 58.3%, respectively), with soil bulk density emerged as the most influential single factor, explaining 18.6% and 24.5% of the relative importance for yield and ET, respectively. Overall, this study provides robust empirical evidence supporting the application of RT across diverse agroecosystems. By integrating microclimatic, physiological, and soil factors at a global scale, our study offers novel insights into the mechanisms driving RT effectiveness—highlighting a new direction for site-specific optimization of conservation tillage strategies under changing environmental conditions.