Shaanxi Provincial Land Engineering Construction Group Co., Ltd., Shaanxi, Xi'an, China.
Institute of Land Engineering and Technology, Shaanxi Provincial Land Engineering Construction Group Co., Ltd., Shaanxi, Xi'an, China.
PLoS One. 2019 Jan 25;14(1):e0211163. doi: 10.1371/journal.pone.0211163. eCollection 2019.
Soil microorganisms play a pivotal role in carbon mineralization and their diversity is crucial to the function of soil ecosystems. However, the effects of long-term fertilization on microbial-mediated carbon mineralization are poorly understood. To identify the relative roles of microbes in carbon mineralization of yellow paddies, we investigated the long-term fertilization effects on soil properties and microbial communities and their relationships with carbon mineralization. The treatments included: no fertilization (CK), chemical fertilizer (NPK), organic fertilizer (M), and constant organic-inorganic fertilizer (MNPK). NPK treatment significantly increased soil water content (WC), while M and MNPK treatments significantly increased the content of soil organic carbon (SOC), total nitrogen (TN), soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and WC. Strong increases in CO2 emissions, potential mineralized carbon, and turnover rate constant were observed in both organic-fertilizer treatments (M and MNPK), relative to the CK treatment. These changes in soil properties can be attributed to the variation in microbial communities. NPK treatment had no significant effect. Different fertilization treatments changed soil microbial community; SOC and SMBN were the most important contributors to the variance in microbial community composition. The variations in community composition did not significant influence carbon mineralization; however, carbon mineralization was significantly influenced by the abundance of several non-dominant bacteria. The results suggest that SOC, SMBN, and non-dominant bacteria (Gemmatimonadetes and Latescibacteria), have a close relationship to carbon mineralization, and should be preferentially considered in predicting carbon mineralization under long-term fertilization.
土壤微生物在碳矿化中起着关键作用，其多样性对于土壤生态系统的功能至关重要。然而，长期施肥对微生物介导的碳矿化的影响还知之甚少。为了确定微生物在黄稻土壤碳矿化中的相对作用，我们研究了长期施肥对土壤性质和微生物群落的影响及其与碳矿化的关系。处理包括：不施肥（CK）、化肥（NPK）、有机肥（M）和常量有机-无机肥（MNPK）。NPK 处理显著增加了土壤含水量（WC），而 M 和 MNPK 处理显著增加了土壤有机碳（SOC）、总氮（TN）、土壤微生物生物量碳（SMBC）、土壤微生物生物量氮（SMBN）和 WC 的含量。与 CK 处理相比，两种有机肥处理（M 和 MNPK）均显著增加了 CO2 排放、潜在可矿化碳和周转率常数。土壤性质的这些变化可归因于微生物群落的变化。NPK 处理没有显著影响。不同的施肥处理改变了土壤微生物群落；SOC 和 SMBN 是微生物群落组成变异的最重要贡献者。群落组成的变化对碳矿化没有显著影响；然而，碳矿化受到几种非优势细菌丰度的显著影响。结果表明，SOC、SMBN 和非优势细菌（Gemmatimonadetes 和 Latescibacteria）与碳矿化密切相关，在预测长期施肥下的碳矿化时应优先考虑。
