Improving crop yield and water use efficiency (WUE) is essential for global agricultural sustainability, with water-nitrogen co-limitation as a major constraint. The combined application of drip irrigation and organic fertilizer (DIOF), a promising ecological practice, lacks comprehensive understanding regarding its effects and underlying mechanisms across diverse environments. A global meta-analysis of 114 studies (1428 paired observations) evaluated its impacts on production efficiency, nitrogen cycling, and soil physicochemical properties. The results demonstrated that DIOF significantly enhanced crop yield (+20.0%), WUE (+31.9%), soil available nitrogen (+25.9%), crop nitrogen uptake (+23.6%), and soil organic carbon (+22.6%), without inducing soil acidification or salt accumulation. Humic acid fertilizers and animal-derived organic fertilizers were optimal; clay loam and strongly acidic soils (pH<6) exhibited the greatest yield and WUE improvements. Cash crops were most responsive (+36.7% yield increase), with food crops also adaptable (+20.7% WUE increase). Random forest and partial least squares structural equation modeling (PLS-SEM) analyses identified available nitrogen, mean annual precipitation, soil pH, and crop nitrogen uptake as key driving factors for yield and WUE. CNU is strongly associated with WUE and yield enhancement, serving as a key predictive factor, while nitrogen transformation and SOC form key regulatory linkages. This study clarifies optimal parameters for synchronously optimizing production efficiency and soil health, providing a sustainable strategy for agricultural resource use and supporting global food security. • Drip irrigation and organic fertilizer (DIOF) increases crop yield by 20.0% and water use efficiency (WUE) by 31.9% globally. • Crop nitrogen uptake is the key driver, with AN and SOC regulating synergy. • Humic acid and animal-derived fertilizers perform best in acidic clay loam and cash crops. • DIOF enhances productivity and soil health without acidification or salinization.
Fan et al. (Fri,) studied this question.