Biodegradable film (BM) presents a promising replacement for plastic film (PM). However, the ability of BM to substitute PM across different crops and regions remains unclear. This study compared the effects of BM and PM on cotton, maize, potato, and wheat by conducting a meta-analysis of yield responses and employing a random forest model to identify key drivers under film mulching. Furthermore, an XGBoost model was applied to simulate spatial yield changes under current and future climate conditions across China’s agro-regions. The meta-analysis indicated that the overall yield enhancement under PM (30.0%) was significantly higher than under BM (26.5%), with a relatively small difference between the two films. The Northern Arid and Semi-Arid Region showed a significant difference, with yield increases of 37.8% under PM and 28.5% under BM. BM resulted in an 18.7% increase in economic return, whereas PM led to a 32% increase. Both BM and PM enhanced the yield of all four crops, but PM had a greater effect on maize (31.8% vs. 28.0%). Random forest identified mean annual temperature (MAT), precipitation (MAP) and nitrogen application rate (N) as the main drivers influencing yield responses under film mulching. Under conditions of MAT < 10 °C, MAP < 450 mm and N ≥ 200 kg ha−1, PM outperformed BM. However, the yield benefits associated with BM will strengthen over time under future climate scenarios. Future scenarios simulations suggested that BM’s relative advantage may increase, particularly for maize, across certain regions. These findings offer region-specific mulching strategies that promote a sustainable agricultural environment.
Xu et al. (Sat,) studied this question.