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通过盆栽和田间试验表明，重迎茬大豆根际微生物数量变化的主要特征表现在细菌和放线菌数量减少，真菌数量增多，故Ｂ／Ｆ和Ａ／Ｆ比值明显下降，并随重茬年次的增加，其变化幅度增大。在重茬条件下连年施用氮磷化肥处理较不施肥处理，耕层（１５－２０ｃｍ）土壤细菌数量减少６０％，Ｂ／Ｆ比值下降４０％；但连年施用有机肥或秸杆还田的处理，使细菌和放线菌数量显著增加，同时也使真菌数量明显减少，故Ｂ／Ｆ和Ａ／Ｆ比值将相应提高。
The pot and field experiments showed that the main characteristics of rhizosphere microbes in heavy replanting soybean were the decrease in the number of bacteria and actinomycetes and the increase in the number of fungi. Therefore, the ratio of B / F and A / F decreased significantly, Of the increase, the magnitude of its increase. Under continuous cropping condition, nitrogen and phosphorus fertilizers were applied in successive years with no fertilizer application. The amount of bacteria in the topsoil (15-20cm) decreased by 60% and the B / F ratio decreased by 40%. However, So that the number of bacteria and actinomycetes significantly increased, but also significantly reduced the number of fungi, so B / F and A / F ratio will be increased accordingly.