Abstract Cover crops have been increasingly grown for improving soil health and crop production and minimizing environmental impact compared to no cover crop. Systematic documentation of cover cropping effects on soil microbial abundance and community structure, however, is scarce. A meta-analysis including data from 81 available studies was conducted to elucidate the effect of “cover crop” versus “no cover crop” on soil microbial community abundance and structure. Microbial biomass C and N (MBC and MBN) and total phospholipid-derived fatty acids (PLFA) were taken as proxies for soil microbial abundance, and total fungi, total bacteria, gram-positive and -negative bacteria, actinomycete, and arbuscular mycorrhizal fungi (AMF) for microbial community structure. Compared to no cover crop, cover crop overall enhanced PLFA, MBC, and MBN by 24, 40, and 51%, respectively. Soil total bacteria and total fungi, and the groups in them increased by 7–31% with cove crop compared to no cover crop. Fungi were affected more by cover crop than bacteria as indicated by the greater fungi/bacteria ratio. In depth categorical meta-analyses revealed that the legume and nonlegume cover crop mixture reduced MBC, PLFA, and actinomycete compared to legume or nonlegume cover crop alone. Legume cover crop enhanced actinomycete in comparison to nonlegume or the cover crop mixture. Incorporation of cover crop residue into the soil increased PLFA, total bacteria, AMF root colonization, and spore density, but decreased gram-positive and -negative bacteria and AMF compared to residue placed at the surface or removed from the soil. Microbial parameters due to cover crop compared to no cover crop were related to soil properties and annual precipitation. Medium-textured soils showed greater response of cover crop on PLFA, total bacteria and fungi, and actinomycete than fine- or coarse-textured soils. We conclude that cover crops enhance soil microbial community biomass and affected community structure compared to no cover crop and the responses of microbial parameters to cover crop varied with soil and climatic conditions. Cover crops can enhance biological soil health by enhancing microbial community abundance compared to no cover crop.

中文翻译：

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覆盖作物增强土壤微生物生物量并影响微生物群落结构：荟萃分析

摘要 与没有覆盖作物相比，覆盖作物的种植越来越多，以改善土壤健康和作物生产，并最大限度地减少对环境的影响。然而，关于覆盖作物对土壤微生物丰度和群落结构的影响的系统文献很少。进行了包括 81 项可用研究数据的荟萃分析，以阐明“覆盖作物”与“无覆盖作物”对土壤微生物群落丰度和结构的影响。微生物生物量C和N（MBC和MBN）和总磷脂衍生脂肪酸（PLFA）作为土壤微生物丰度的代理，以及总真菌、总细菌、革兰氏阳性和阴性细菌、放线菌和丛枝菌根真菌(AMF) 用于微生物群落结构。与没有覆盖作物相比，覆盖作物总体上将 PLFA、MBC 和 MBN 提高了 24、40、和 51%，分别。与没有覆盖作物相比，覆盖作物的土壤总细菌和真菌总数增加了 7-31%。正如更大的真菌/细菌比率所表明的那样，真菌比细菌更受覆盖作物的影响。深入的分类荟萃分析显示，与单独的豆类或非豆类覆盖作物相比，豆类和非豆类覆盖作物混合物减少了 MBC、PLFA 和放线菌。与非豆类或覆盖作物混合物相比，豆类覆盖作物增强了放线菌。将覆盖作物残留物掺入土壤中会增加 PLFA、总细菌、AMF 根系定植和孢子密度，但与放置在表面或从土壤中去除的残留物相比，革兰氏阳性和阴性细菌和 AMF 减少。与没有覆盖作物相比，覆盖作物的微生物参数与土壤特性和年降水量有关。中等质地的土壤比细质地或粗质地土壤显示出覆盖作物对 PLFA、总细菌和真菌以及放线菌的更大反应。我们得出结论，与没有覆盖作物相比，覆盖作物增强了土壤微生物群落生物量并影响了群落结构，并且微生物参数对覆盖作物的响应随土壤和气候条件而变化。与没有覆盖作物相比，覆盖作物可以通过提高微生物群落丰度来增强生物土壤健康。我们得出结论，与没有覆盖作物相比，覆盖作物增强了土壤微生物群落生物量并影响了群落结构，并且微生物参数对覆盖作物的响应随土壤和气候条件而变化。与没有覆盖作物相比，覆盖作物可以通过提高微生物群落丰度来增强生物土壤健康。我们得出结论，与没有覆盖作物相比，覆盖作物增强了土壤微生物群落生物量并影响了群落结构，并且微生物参数对覆盖作物的响应随土壤和气候条件而变化。与没有覆盖作物相比，覆盖作物可以通过提高微生物群落丰度来增强生物土壤健康。