Yan Qing, Li Yanpei, Wang Tongtong, Chen Yi, Zhao Jinze, Jiang Jiarui, Lu Haodong, Jia Hanzhong
Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China.
Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China.
Sci Total Environ. 2025 Jan 10;959:178198. doi: 10.1016/j.scitotenv.2024.178198. Epub 2024 Dec 24.
Plastic films mulching, a management strategy designed to boost agricultural productivity, significantly impacts soil fertility and the turnover of soil organic carbon (SOC). Aggregates in the soil play a crucial role in this SOC cycling. Yet, the effect of mulching on the changes in organic carbon components and the mineralization at the aggregate scale is still not well understood. We conducted a three-year field experiment to examine the effects of various mulching types (CK: non-mulching, BPM: black polyethylene mulching, CPM: colorless polyethylene mulching, BDM: black degradable mulching, CDM: colorless degradable mulching) on the transformation and mineralization of organic carbon within soil aggregates. Generally, after three years of continuous mulching, compared to CK, soil aggregate stability significantly improved, the content of SOC and HFOC increased by 8-14 % and 12-24 % respectively, while the content of LFOC decreased by 3-51 %. The response mechanisms of organic carbon mineralization in different size aggregates to mulching are different. The change in carbon components is the main factor stimulating the mineralization of organic carbon in >0.25 mm aggregates; microbial diversity is the dominant factor inhibiting the mineralization of organic carbon in 0.053-0.25 mm aggregates; while <0.053 mm aggregates are not significantly affected by mulching. Our findings suggest that plastic mulching reduce the mineralization of SOC and enhances its sequestration by modulating the composition of organic carbon fractions, extracellular enzymes, and microorganisms within soil aggregates of different sizes. This study provides a valuable reference for gaining further insights into the turnover dynamics of soil organic carbon at the aggregate scale.
地膜覆盖是一种旨在提高农业生产力的管理策略，对土壤肥力和土壤有机碳（SOC）周转有显著影响。土壤团聚体在这种SOC循环中起着关键作用。然而，地膜覆盖对团聚体尺度上有机碳组分变化和矿化的影响仍未得到充分理解。我们进行了一项为期三年的田间试验，以研究不同地膜覆盖类型（CK：不覆盖，BPM：黑色聚乙烯地膜覆盖，CPM：无色聚乙烯地膜覆盖，BDM：黑色可降解地膜覆盖，CDM：无色可降解地膜覆盖）对土壤团聚体内有机碳转化和矿化的影响。总体而言，连续三年地膜覆盖后，与CK相比，土壤团聚体稳定性显著提高，SOC和HFOC含量分别增加了8%-14%和12%-24%，而LFOC含量下降了3%-51%。不同粒径团聚体中有机碳矿化对地膜覆盖的响应机制不同。碳组分变化是刺激>0.25mm团聚体中有机碳矿化的主要因素；微生物多样性是抑制0.053-0.25mm团聚体中有机碳矿化的主导因素；而<0.053mm团聚体受地膜覆盖影响不显著。我们的研究结果表明，地膜覆盖通过调节不同粒径土壤团聚体内有机碳组分、胞外酶和微生物的组成，减少了SOC的矿化并增强了其固存。本研究为进一步了解团聚体尺度上土壤有机碳的周转动态提供了有价值的参考。
