【摘要】 连作与轮作大生各生育期土壤微生物生态分布和大豆孢囊线虫群体动态的研究结果表明,无论上壤微生物总数或大豆根表微生物总数的动态变化,均以细菌数量占绝对优势,其次是放线菌。真菌最少。根表微生物总数大于土壤微生物总数的几十倍到100多倍。大豆各生育期微生物总数以开花期为最多,其次是成熟期.再次是分枝期。根瘤密度和大豆孢囊密度以成熟期为最大,其次是开花期,分枝期最小。微生物总数和根瘤密度,轮作区高于连作区。孢囊密度则相反,连作区高于轮作区。值得注意的是,真菌数量动态变化与孢囊密度动态变化是一致的.其次序是分枝期<开花期<成熟期。这种吻合可能有着内在的联系,有待进一步研究。更多还原

【Abstract】 The artical reported ecologcal distribution of soil microorganisms on different growing period of soybean in continuous and rotation cropping systems. Population dynamis of Heterodera glycines were also studied. The result showe that in the continuous and rotation cropping system bacteria daminante over other kinds of microorganisms whether for the total amount of soil microorganisms or for root surface microorganisms. The second dominant race was actinomycete. The amount of fungi was ths least. The total amount of root surface microorganisms was about 100 times over that of the soil microorganisms. The largest total amount of soil microorganism and root sursace microorganism was on the flowering stage. The highest density of root nodules and Heteroera glycines cyst was in the pod-setting stage, flowering stage the next, the least densities of root nodules and neinatode cyst was on the branching stage. The total amount of microorganisms and the densities of the root nodules ia the continuous cropping system was higher than those in the rotation cropping system. And toe densities of cyst-forming netnatodes in the continuous cropping field was higher than those in the rotation cropping system. The extra attention was deserved that the dynamic change of the amount of fungi and the change of cyst density was the same. The frend of the change was branching stage<flowering stage<pod-setting stage. The sameness may have some internal connection. The problem will be studied further.更多还原