Long-term plastic film mulching increased maize yield and water use efficiency

The Loess Plateau plays an important role in ensuring food security in China. In the past few decades, the plastic film mulching (PFM) system has been widely used in the Loess Plateau, but whether PFM technology can maintain the stability of yield and the sustainability of soil water in the Loess Plateau remains uncertain. To clarify whether PFM technology can maintain yield stability and soil water sustainability in the Loess Plateau, and reveal the effects of PFM on water use, yield, and regional water balance. Using a 12-year field experiment (2012–2023), meta-analysis, and data-driven modeling, we demonstrated the following. (1) In the Loess Plateau, compared to the CK treatment, PFM and film mulching with nutrient management (PFM+N) significantly improved both water use efficiency (WUE; +28 %, +31 %, respectively) and yield (+21 %, +33 %) in maize, and PFM+N synergistically enhanced yield stability (coefficient of variation 32.36 %) and sustainability (Sustainability Yield Index 0.5). (2) Future climate scenario simulations revealed that from 2021 to 2040, both CK and PFM treatments showed an increasing trend in the proportion of water-deficit areas across the Loess Plateau. However, PFM demonstrated critical compensatory advantages by improving precipitation use efficiency and optimizing annual soil moisture redistribution, effectively alleviating regional water imbalance. (3) Spatial analysis using data-driven models further indicated that PFM mitigated water deficits in the central, western, and northern regions (which have relatively low precipitation) through reduced evapotranspiration losses, whereas in southern areas characterized by relatively high precipitation, non-mulching practices proved more ecologically sustainable because excessive PFM use would disrupt natural hydrological cycles. while non-mulching practices proved more ecologically sustainable in southern areas where excessive PFM use could disrupt natural hydrological cycles. Overall, the PFM system effectively alleviated the overall water consumption of the Loess Plateau, significantly increased WUE and maize yield, and, of great significance to sustainable development, the effect was best in low rainfall areas (Northwest of the Loess Plateau. Growing season precipitation: <250 mm; non-cropped precipitation:<200 mm). In the long run, PFM could effectively ensure water resource sustainability in the Loess Plateau, thereby laying a solid foundation for sustainable agricultural development in the region. • PFM+N treatment enhanced yield stability and sustainability more significantly than N treatment. • PFM mitigated regional water imbalance on the Loess Plateau by improving precipitation use efficiency. • PFM effectively mitigated water deficits in the water-scarce central, western, and northern regions of the Loess Plateau.