覆盖是提高作物产量和实现反季节生产的常用方法;然而,它们的移除会对环境造成重大威胁。在这种情况下,使用可生物降解的塑料覆盖物作为增加这种做法可持续性的解决方案,因为它们可以在土壤中耕种而不会对环境造成风险。在这种情况下,重要的是研究微生物对这种做法的反应,考虑到它们直接参与塑料的生物降解。这项研究评估了三种商业覆盖物残留物的生物降解:一种常规的不可生物降解的覆盖物与两种可生物降解的覆盖物(白色和黑色可堆肥的Mater-Bi覆盖物)。实验是在三个孵育温度下进行的(室温20-25°C,30°C,和45°C),使用休耕农业土壤进行6个月的试验。没有塑料覆盖物残留物的土壤用作对照。白色物质-可生物降解的覆盖物残留物在30°C下显示出更高的降解率,高达88.90%,在室温下高达69.15%。此外,在45°C下孵育确定所考虑的所有类型的覆盖物不存在降解。此外,细菌α多样性主要受塑料类型和温度的影响,而真菌种群主要受温度影响。β多样性受到所有实验变量的影响。预测的功能基因对降解复杂的底物至关重要,包括那些编码水解酶的,角质,纤维二糖糖苷酶,和脂肪酶,来自16SrRNA基因测序数据。基于预测的酶编码基因丰度的聚类分析揭示了两个簇,主要与采样时间有关。最后,核心微生物组分析确定了降解过程中各种土壤-塑料生态系统中的优势细菌和真菌类群,精确定位可能参与塑料分解的物种。本研究允许评估不同温度如何影响土壤中覆盖物残留物的降解,为不同的气候生长区提供重要的见解。通过直接比较可生物降解和聚乙烯覆盖物对土壤微生物群落的影响,它也填补了文献中的空白。
Mulching is a common method increasing crop yield and achieving out-of-season production; nevertheless, their removal poses a significant environmental danger. In this scenario, the use of biodegradable plastic mulches comes up as a solution to increase the sustainability of this practice, as they can be tilled in soil without risk for the environment. In this context, it is important to study the microbial response to this practice, considering their direct involvement in plastic biodegradation. This study evaluated the biodegradation of three commercial mulch residues: one conventional non-biodegradable mulch versus two biodegradable ones (white and black compostable Mater-Bi mulches). The experiment was conducted under three incubation temperatures (room temperature 20-25 °C, 30 °C, and 45 °C) for a 6-month trial using fallow agricultural soil. Soil without plastic mulch residues was used as a control. White mater-bi biodegradable mulch residues showed higher degradation rates up to 88.90% at 30 °C, and up to 69.15% at room temperature. Furthermore, incubation at 45 °C determines the absence of degradation for all types of mulch considered. Moreover, bacterial alpha diversity was primarily influenced by plastic type and temperature, while fungal populations were mainly affected by temperature. Beta diversity was impacted by all experimental variables. Predicted functional genes crucial for degrading complex substrates, including those encoding hydrolases, cutinases, cellobiosidases, and lipases, were derived from 16S rRNA gene sequencing data. Cluster analysis based on predicted enzyme-encoding gene abundance revealed two clusters, mainly linked to sampling time. Finally, core microbiome analysis identified dominant bacterial and fungal taxa in various soil-plastic ecosystems during degradation, pinpointing species potentially involved in plastic breakdown. The present study allows an assessment of how different temperatures affect the degradation of mulch residues in soil, providing important insights for different climatic growing zones. It also fills a gap in the literature by directly comparing the effects of biodegradable and polyethylene mulches on soil microbial communities.