Sub-soil biodegradable film mulching: a sustainable solution for enhancing winter wheat yield and shaping soil microbial communities in saline-alkali soils

Abstract

Film mulching offers numerous benefits for enhancing crop yield in saline-alkali soils, yet the severe pollution caused by traditional polyethylene films and the lack of research on the impact of biodegradable films on microbial communities remain significant concerns. In this study, we compared the differences in bacterial and fungal communities among different mulching treatments, including polyethylene film (conventional mulching, PM; sub–soil film mulching, PMF) and biodegradable film (conventional mulching, BM; sub–soil film mulching, BMF). Film mulching can inhibit salinity, enhance moisture retention and nutrient uptake, thereby increasing the yield of winter wheat (Triticum aestivum L.). Among these, the sub–soil film mulching treatment demonstrated significant effectiveness, and BMF achieved a yield similar to that of PMF. Changes in soil environmental factors under different mulching treatments significantly influenced the microbial communities: BMF increased bacterial diversity and evenness, while PMF enriched fungal diversity. BMF exhibited higher abundance of Pyronemataceae and a more stable bacterial co-occurrence network. PMF, on the other hand, showed a reduced presence of pathogens and a more complex fungal network structure. Sub–soil film mulching regulated soil moisture, salinity, and nutrient status, leading to beneficial enrichment of the microbial community and promoting crop growth, ultimately enhancing crop yield. Our research provides theoretical insights into the reasons behind the increased yield observed with sub–soil film mulching and explores the potential of BMF as a substitute for PMF.