Microorganisms play a key role in nutrient cycling in agriculture and can contribute to improve soil quality and enhance crop production. Thus, there is a need to identify the most suitable management practices which foster increases in soil microbial biomass and diversity. A meta-analysis was performed to assess changes in microbial abundance in agricultural soils affected by: (i) management practices (tillage, fertilization and crop diversification); and (ii) environmental factors, including climate characteristics and soil properties. The scope of the meta-analysis was to evaluate whether microbial abundances are affected or not by organic fertilization or no fertilization, crop diversification (intercropping and crop rotations) and conservation tillage (reduced tillage/no-tillage) as an alternative to intensive conventional monocultures in agriculture. Only papers showing data on phospholipid fatty acids (PLFAs), providing indicators about soil microbial (total PLFA), fungal and bacterial biomass reached a critical mass to perform the meta-analysis. Therefore, soil microbial diversity could not be analyzed considering different management practices. Results showed that intercropping and crop rotations only significantly increased the abundance of fungi, with the corresponding increase in the fungal-to-bacterial ratio. Organic fertilization contributed to significant increases in bacterial and fungal abundance and total PLFA compared to mineral fertilization. Contrarily, the lack of fertilization negatively affected total PLFA, with no significant effect on bacterial and fungal abundances. Reduced tillage significantly increased total PLFA, fungal and bacterial abundances compared to conventional tillage, while no tillage had only a positive effect on fungi. Thus, as a general pattern, the adoption of sustainable management practices, mostly organic fertilization and reduced tillage, has overall positive effects on soil total microbial, fungal and bacterial abundance. These variables were not related to soil physicochemical properties and climatic factors, suggesting a positive global effect of sustainable management practices on soil microbial abundances. Thus, this study shows new insights by a meta-analysis of global studies about the effect of sustainable management practices on soil microbial abundances, needed for land-managers, policy-makers and farmers to select sustainable cropping systems that enhance microbial abundance.

微生物在农业养分循环中发挥着关键作用，有助于改善土壤质量和提高作物产量。因此，需要确定促进土壤微生物生物量和多样性增加的最合适的管理实践。进行了一项荟萃分析，以评估受以下因素影响的农业土壤中微生物丰度的变化： (i) 管理做法（耕作、施肥和作物多样化）；(ii) 环境因素，包括气候特征和土壤特性。荟萃分析的范围是评估微生物丰度是否受到有机施肥或不施肥的影响，作物多样化（间作和轮作）和保护性耕作（减少耕作/免耕）作为农业中传统集约化单一栽培的替代方案。只有显示磷脂脂肪酸 (PLFA) 数据、提供土壤微生物（总 PLFA）、真菌和细菌生物量指标的论文达到了进行荟萃分析的临界质量。因此，考虑到不同的管理实践，无法分析土壤微生物多样性。结果表明，间作和轮作仅显着增加了真菌的丰度，并相应增加了真菌与细菌的比例。与矿物施肥相比，有机施肥有助于显着增加细菌和真菌丰度以及总 PLFA。相反，缺乏受精对总PLFA产生负面影响，对细菌和真菌丰度没有显着影响。与常规耕作相比，减少耕作显着增加总 PLFA、真菌和细菌丰度，而免耕仅对真菌产生积极影响。因此，作为一般模式，采用可持续管理做法，主要是有机施肥和减少耕作，对土壤微生物、真菌和细菌的总丰度具有总体积极影响。这些变量与土壤理化性质和气候因素无关，表明可持续管理实践对土壤微生物丰度具有积极的全球影响。因此，本研究通过对可持续管理实践对土壤微生物丰度影响的全球研究进行荟萃分析，展示了新的见解，