可生物降解的微塑料(MP)已被释放到农业土壤中,并不可避免地经历各种老化过程。秸秆还田是许多国家流行的农业管理策略。然而,秸秆还田对淹水水稻土中可降解MPs老化过程的影响,这对于研究特征至关重要,命运,以及可生物降解的MPs对环境的影响,尚不清楚。这里,我们构建了一个180天的微观孵化,以阐明聚乳酸(PLA)-MPs在富含稻草的水稻土中的老化机理。这项研究阐明了PLA-MPs的显着老化特征发生在富含秸秆的稻田土壤中,伴随着色度增加(76.64-182.3%),亲水性(2.92-22.07%),粗糙度(33.12-58.01%),PLA-MPs的生物膜形成(42.12-100.3%),特别是2%(w/w)秸秆还田处理(P<0.05)。2%的秸秆还田处理显著影响了PLA-MPs酯CO组的变化,改变了MPs附着的土壤细菌群落组成,强化细菌网络结构,提高了土壤蛋白酶K活性。这项工作的结果表明,洪水淹没,秸秆富集水稻土受土壤-水化学影响加速PLA-MPs老化,土壤微生物,和土壤酶。本研究有助于加深对秸秆还田水稻土中PLA-MPs老化过程的认识。环境含义:微塑料(MPs)是全球土壤和陆地生态系统中新兴的污染物。在老化过程中,可生物降解的MPs更有可能形成并释放到农业土壤中。秸秆还田是许多国家流行的农业管理策略。考虑到塑料薄膜的广泛使用,污水污泥,塑料涂层肥料,农业生态系统中的有机肥料,关注秸秆富集水稻土中可降解MPs的老化过程,这一点没有得到充分强调。这一方面在以前的研究中被忽略,并威胁到生态系统。这项研究表明,富含秸秆的稻田土壤加速了聚乳酸(PLA)-MPs的老化受溶解有机物的影响。微生物,和与秸秆分解相关的酶活性。
Biodegradable microplastics (MPs) have been released into agricultural soils and inevitably undergo various aging processes. Straw return is a popular agricultural management strategy in many countries. However, the effect of straw return on the aging process of biodegradable MPs in flooded paddy soil, which is crucial for studying the characteristics, fate, and environmental implications of biodegradable MPs, remains unclear. Here, we constructed a 180-day microcosm incubation to elucidate the aging mechanism of polylactic acid (PLA)-MPs in straw-enriched paddy soil. This study elucidated that the prominent aging characteristic of PLA-MPs occurred in the straw-enriched paddy soil, accompanied by increased chrominance (76.64-182.3 %), hydrophilicity (2.92-22.07 %), roughness (33.12-58.01 %), and biofilm formation (42.12-100.3 %) for the PLA-MPs, especially with 2 % (w/w) straw return treatment (P < 0.05). A 2 % straw return treatment has significantly impacted ester CO group changes in PLA-MPs, altered the MPs-attached soil bacterial communities composition, strengthened bacterial network structure, and increased soil proteinase K activity. The findings of this work demonstrated that flooded, straw-enriched paddy soil accelerated PLA-MPs aging affected by soil-water chemistry, soil microbe, and soil enzymatic. This study helps to deepen our understanding of the aging process of PLA-MPs in straw return paddy soil. ENVIRONMENTAL IMPLICATION: Microplastics (MPs) are emerging contaminants in the global soil and terrestrial ecosystems. Biodegradable MPs are more likely to be formed and released into agricultural soils during aging. Straw return is a popular agricultural management strategy in many countries. Considering the wide use of plastic film, sewage sludge, plastic-coated fertilizer, and organic fertilizer in agricultural ecosystems, it is crucial to pay attention to the aging process of biodegradable MPs in straw-enriched paddy soil, which has not been adequately emphasized. This aspect has been overlooked in previous studies and threatens ecosystems. This study demonstrated that straw-enriched paddy soil accelerated polylactic acid (PLA)-MPs aging influenced by the dissolved organic matter, microorganisms, and enzyme activity associated with straw decomposition.