Boosting productivity while cutting carbon, nitrogen, and water footprints: An integrated practice of white film mulching and controlled-release urea for semi-arid forage maize

: Sustainable intensification of rainfed agriculture in semi-arid regions requires strategies that enhance productivity while mitigating environmental footprints. A two-year field trial was performed on the Loess Plateau to evaluate the synergistic effects of film mulching (white, black, and no mulching) and nitrogen management (conventional urea at 270 and 200 kg N ha -1 ; controlled-release urea at 170 and 140 kg N ha -1 ) on forage maize ( Zea may L.) productivity, resource use efficiency, energy performance, and multi-scale carbon (C), nitrogen (N), and water footprints. White film mulching notably raised the thermal time use efficiency (TUE) by 12.5% in 2023 compared to no mulching. Notably, film mulching greatly increased dry matter production (DMP) by 7.0–24.1%, precipitation productivity (PP DM ) by 7.4–24.1% and partial nitrogen balance (PNB) by 9.8–21.1% without increasing seasonal water loss. White film yielded the greatest DMP and energy output (EO), and net energy (NE), while consistently reduced C, N, and water footprints across both dry matter- and nutrient-based functional units. The controlled-release urea strategy at 140 kg N ha -1 maintained yield with 48% less nitrogen input while simultaneously reducing C, N, and water footprints across dry matter- and nutrient-based functional units, and significantly enhancing PNB, NE, energy ratio (ER), energy use efficiency (EUE), and energy productivity. Consequently, white film mulching combined with reduced-dose controlled-release urea (140 kg N ha -1 ) achieved the highest sustainability evaluation index (0.90), demonstrating an optimal balance between productivity and environmental performance. This integrated strategy represents an effective practice for sustainable intensification of rainfed forage maize production in semi-arid agroecosystems.