Soil microbial community and enzyme activity regulate carbon and nutrient cycling in soils. No‐till has elevated levels of carbon at the soil surface compared to intensively tilled soils. The introduction of crop diversification in agricultural systems increases soil carbon protection and aggregate stability. Thus, the association of no‐till with crop diversification may change the soil microbial distribution and enhance activity in comparison with tilled soils with no crop diversification. We tested this hypothesis assessing the soil microbial community and enzyme activity in a long‐term (32 yr) experiment with contrasting soil management (no‐tillage, (NT) and conventional tillage (CT)) and cropping systems in southern Brazil. Long‐term NT increased microbial biomass at 0–5 cm. In contrast, soil microbial biomass was higher in deeper soil layers (10–30 cm) of CT. No‐tillage and crop diversification increased the activity of β‐glucosidase, acid phosphatase and N‐acetyl‐glucosaminidase. The benefits of an intensified/diversified crop rotation were offset by soil tillage. The higher abundance of PLFA groups at 0–5 cm and 10–30 cm of respective NT and CT soils were correlated with increased C and nutrient levels (N, Ca²⁺, Mg²⁺) and decreased Al³⁺_.

中文翻译：

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免耕的多种作物轮作会随着深度改变微生物分布，并增强亚热带Oxisol的活性

土壤微生物群落和酶活性调节土壤中的碳和养分循环。与耕作土壤相比，免耕在土壤表面的碳含量升高。在农业系统中引入农作物多样化可以增加土壤碳保护和骨料稳定性。因此，与没有耕作多样化的耕作土壤相比，免耕与作物多样化的联系可能会改变土壤微生物的分布并增强活性。我们在一项长期（32年）实验中评估了土壤微生物群落和酶活性的假设，并与巴西南部的土壤管理（免耕（NT）和常规耕作（CT））和耕作制度进行了对比。长期NT在0-5 cm处增加了微生物量。相反，CT的深层土壤（10–30 cm）土壤微生物量较高。免耕和作物多样化增加了β-葡萄糖苷酶，酸性磷酸酶和N-乙酰氨基葡萄糖苷酶 耕作增加/多样化的好处被土壤耕种所抵消。在0-5厘米和10-30厘米各自NT和CT土壤的丰度更高磷脂脂肪酸基团的具有增加的C和营养水平（N，钙有相关性²⁺，镁²⁺）和降低的Al ^{3 +} _。