Cheng Kun, Wang Xiaoyue, Fu Libo, Wang Wei, Liu Ming, Sun Bo
Key Laboratory of Poyang Lake Basin Agricultural Resource and Ecology of Jiangxi Province, College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
Front Microbiol. 2023 Aug 22;14:1233465. doi: 10.3389/fmicb.2023.1233465. eCollection 2023.
Legume crops in rice cultivation are typically rotated and incorporated into the soil as green manure to improve soil fertility. Biochar has recently been co-incorporated with green manure to simultaneously stimulate soil organic carbon (SOC) mineralization and increase carbon (C) sequestration. However, few studies examine the effects of the co-incorporation of biochar and green manure on C cycling and the underlying microbial mechanisms in paddy fields. In this study, the effects of the co-incorporation of green manure and biochar on C mineralization, dissolved organic carbon (DOC) characteristics, and microbial community structures were investigated. A pot study was conducted with three treatments: inorganic NPK (NPK), inorganic NPK + green manure (GM), and inorganic NPK + green manure + biochar (GMC). Organic amendments significantly increased cumulative C mineralization, with amounts in the order GMC (3,434 mg·kg) > GM (2,934 mg·kg) > NPK (2,592 mg·kg). Fertilizer treatments had similar effects on DOC concentrations, with amounts in the order GMC (279 mg·kg) > GM (255 mg·kg) > NPK (193 mg·kg). According to fluorescence spectra, the highest microbial humic acid-like fraction and biological index were also in GMC. Co-incorporation of green manure and biochar shifted the composition of bacterial and fungal communities but more importantly, increased fungal network complexity and decreased bacterial network complexity. The increase in fungal network complexity with the increase in DOC concentrations and microbially derived components was the dominant factor in promoting C mineralization. Overall, this study reveals the underlying biochemical mechanism, the interaction between DOC and fungal network of C cycling in paddy soil under the co-incorporation of green manure and biochar management, and provides fundamental knowledge for exploring effective approaches to improve soil fertility and health in the future.
在水稻种植中，豆类作物通常会进行轮作，并作为绿肥翻耕入土以提高土壤肥力。最近，生物炭已与绿肥共同施用，以同时刺激土壤有机碳（SOC）矿化并增加碳（C）固存。然而，很少有研究探讨生物炭与绿肥共同施用对稻田碳循环及潜在微生物机制的影响。在本研究中，调查了绿肥与生物炭共同施用对碳矿化、溶解有机碳（DOC）特性和微生物群落结构的影响。进行了一项盆栽试验，设置了三种处理：无机氮磷钾（NPK）、无机氮磷钾+绿肥（GM）和无机氮磷钾+绿肥+生物炭（GMC）。有机改良剂显著增加了累积碳矿化量，其顺序为GMC（3434 mg·kg）＞GM（2934 mg·kg）＞NPK（2592 mg·kg）。施肥处理对DOC浓度有类似影响，其顺序为GMC（279 mg·kg）＞GM（255 mg·kg）＞NPK（193 mg·kg）。根据荧光光谱，微生物类腐殖酸组分和生物学指数最高的也是GMC。绿肥与生物炭共同施用改变了细菌和真菌群落的组成，但更重要的是，增加了真菌网络复杂性并降低了细菌网络复杂性。真菌网络复杂性随DOC浓度和微生物衍生组分的增加而增加是促进碳矿化的主导因素。总体而言，本研究揭示了绿肥与生物炭共同管理下稻田土壤碳循环中潜在的生化机制、DOC与真菌网络之间的相互作用，并为未来探索提高土壤肥力和健康的有效方法提供了基础知识。
