Impact of Management Strategies on Reducing of Mulching Film Residues Pollution in Arid Regions

Plastic pollution caused by mulching film residues (MFRs) is escalating in arable lands, which affects the function of agricultural ecosystems, and poses a serious obstacle to agricultural sustainable development in arid regions. Internationally, increasing recycling rate of polyethylene (PE) film and adopting biodegradable films are recommended strategies to mitigate plastic pollution in farmland, aiming to increase agricultural sustainability and food security. However, impacts of the future of these strategies remain underexplored. This study estimated MFRs accumulation over the next 50 years under varying PE and polybutylene adipate terephthalate (PBAT) film recovery scenarios: no recovery, and recovery rates increased to 80%, 85%, 90%, and 95%. Additionally, cumulative ecological effects (CEEs) of MFR pollution were assessed based on historical MFRs accumulations of 75 kg hm−2, 160 kg hm−2, 220 kg hm−2, 300 kg hm−2, and 400 kg hm−2, by evaluating direct and indirect ecological effects. The findings revealed that (1) with no recovery, PE film residues could increase by 480 kg hm−2, whereas achieving a 95% recovery rate could limit residues increasing to below the national threshold of 75 kg hm−2, outperforming the 80%, 85%, and 90% recovery rates. On the other hand, using PBAT film would maintain the increasing MFRs below 75 kg hm−2 regardless of recovery rate. (2) Without PE film recovery, CEEs would intensify significantly, as both the direct and indirect effects increase notably, while the CEEs of MFRs could maintain the current status or decrease under the strategy of 95% recovery rate of PE film and using PBAT film, similar to the variation of direct effects. However, indirect effects would persist due to ongoing microplastics (MPs) and phthalate esters (PAEs) released from residual films. Overall, a 95% PE film recycling rate and PBAT film usage emerged as particularly effective strategies for minimizing MFRs accumulation and mitigating ecological impacts over the next 50 years. Further research should prioritize the indirect ecological effects of MFRs, given their persistence despite reduction efforts. The results could provide a theoretical support for agricultural sustainable development in arid regions.