Mulching with polyethylene film is a common technique in rain-fed regions used to address insufficient precipitation and heat, and thus promote crop growth, but it can lead to soil pollution from plastic residues. Biodegradable film mulch (BDM) is assumed to be a viable solution to address this concern. To evaluate the effects of polyethylene and biodegradable film mulching on socio-economic and environmental benefits, a two-year study was conducted on wheat. This experiment explored the influence of mulching practices differing in color and degradation: Black polyethylene mulching (Black PE), Black biodegradable mulching (Black BDM), Clear polyethylene mulching (Clear PE), Clear biodegradable mulching (Clear BDM) and No mulching (NM) on grain yield, economic benefits, greenhouse gas (GHG) emissions, and carbon footprint (CF). In comparison with NM, all four film mulching treatments improved soil hydrothermal conditions. The Clear PE, Clear BDM, Black PE, and Black BDM increased average annual wheat yield by 40 %, 47 %, 47 %, and 60 %, respectively, compared to NM. Clear PE, Black BDM, and Black PE enhanced net returns (17–124 %) compared to NM. However, Clear PE and Clear BDM increased CO2 emissions (43 % and 52 %) and net global warming potential (GWP) (49 % and 17 %) despite reducing yield-scaled GWPdirect and CF compared to NM, likely due to higher wheat grain yields. In contrast, under Black BDM, GWPdirect and yield-scaled GWPdirect decreased significantly compared to NM (by 31 % and 58 %, respectively). When accounting for GHG emissions using soil organic carbon (SOC) sequestration rates and life cycle assessment, the annual CF of Clear BDM, Black PE, and Black BDM was significantly lower by 21.9 %, 30.4 %, and 67.9 %, respectively, compared to NM. Black BDM exhibited the lowest net GWP (1682.3–1727.3 kg CO2-eq ha−1) and CF (261.4–336.0 kg CO2-eq t−1), primarily attributed to increased SOC. In conclusion, the black biodegradable mulching might be a promising solution to enhance wheat grain yield and net returns while mitigate net GWP and CF, providing valuable technical guidance to promote a clean and sustainable agricultural production in rain-fed conditions, and possible support for future research.

中文翻译：

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黑色可生物降解覆盖物提高了谷物产量和净回报，同时减少了黄土高原雨养条件下的碳足迹


聚乙烯薄膜覆盖是雨养地区常用的技术，用于解决降水和热量不足的问题，从而促进作物生长，但它可能导致塑料残留物对土壤的污染。可生物降解的薄膜覆盖物 （BDM） 被认为是解决这一问题的可行解决方案。为了评估聚乙烯和可生物降解薄膜覆盖对社会经济和环境效益的影响，对小麦进行了一项为期两年的研究。本实验探讨了颜色和降解不同的覆盖做法的影响：黑色聚乙烯覆盖 （Black PE）、黑色可生物降解覆盖 （Black BDM）、透明聚乙烯覆盖 （Clear PE）、透明可生物降解覆盖 （Clear BDM） 和无覆盖 （NM） 对粮食产量、经济效益、温室气体 （GHG） 排放和碳足迹 （CF）。与 NM 相比，所有四种薄膜覆盖处理都改善了土壤热液条件。与 NM 相比，Clear PE、Clear BDM、Black PE 和 Black BDM 使小麦年平均产量分别提高了 40 %、47 %、47 % 和 60 %。与 NM 相比，Clear PE、Black BDM 和 Black PE 提高了净回报率 （17-124%）。然而，尽管与 NM 相比，Clear PE 和 Clear BDM 减少了产量规模的 GWPdirect 和 CF，但 Clear PE 和 Clear BDM 增加了 CO2 排放量（43% 和 52%）和净全球变暖潜能值 （GWP）（49% 和 17%），这可能是由于小麦籽粒产量更高。相比之下，在 Black BDM 下，GWPdirect 和产量缩放的 GWPdirect 与 NM 相比显着降低（分别为 31% 和 58%）。当使用土壤有机碳 （SOC） 封存率和生命周期评估考虑温室气体排放时，与 NM 相比，Clear BDM、Black PE 和 Black BDM 的年CF分别显著降低了21.9 %、30.4 %和67.9 %。 黑色 BDM 表现出最低的净 GWP （1682.3–1727.3 kg CO2-eq ha-1） 和 CF （261.4–336.0 kg CO2-eq t-1），这主要归因于 SOC 增加。总之，黑色可生物降解覆盖物可能是一种很有前途的解决方案，可以提高小麦籽粒产量和净收益，同时减轻净 GWP 和 CF，为促进雨养条件下的清洁和可持续农业生产提供有价值的技术指导，并可能为未来的研究提供支持。