Effect of biodegradable PBAT microplastics on the C and N accumulation of functional organic pools in tropical latosol

• DOI: 10.1016/j.envint.2023.108393
• Publication Date: 2023-12-17T00:41:11Z
• Authors: Miao Chen; Ming Cao; Wen Zhang; Xin Chen; Huiran Liu; Ziyu Ning; Licheng Peng; Changhua Fan; Dongming Wu; Meng Zhang; Qinfen Li
• Keywords: Latosol

Microplastics (MPs) pollution is becoming an emerging global stressor for soil ecosystems. However, studies on the impacts of biodegradable MPs C sequestration have been mainly based bulk quantity, without considering storage form C, its persistency and N demand. To address this issue, common poly (butylene adipate-co-terephthalate) (PBAT) was used as model, effects functional organic pools, including mineral-associated (MAOM), particulate (POM) dissolved matter (DOM), were investigated from novel coupled perspective stocks. After adding PBAT-MPs, contents POM-C, DOM-C, MAOM-C increased by 546.9%-697.8%, 54.2%-90.3%, 13.7%-18.9%, respectively. Accordingly, total 116.0%-191.1%. Structural equation modeling showed that pools regulated PBAT input microbial metabolism associated with enzymes. Specifically, debris could be disguised to promote POM formation, which main pathway accumulation. Inversely, DOM-C formation attributed product selective consumption in DOM-N. Random forest model confirmed N-activated (e.g., Nitrospirae) PBAT-degrading bacteria Gemmatinadetes) important taxa accumulation, key enzymes rhizopus oryzae lipas, invertase, ammonia monooxygenase. The accumulation related oligotrophic Chloroflexi Ascomycota) aggregate decreasing DOM-N 46.9%-84.3%, but did not significantly change other pools. Collectively, findings highlight urgency control nutrient imbalance risk labile loss recalcitrant enrichment avoid depressed turnover rate MPs-polluted soil.