鄂尔多斯沙地油蒿根际土壤微生物数量的季节动态

对油蒿根际土壤微生物数量的季节动态、垂直分布及影响微生物分布的环境因子进行了研究。结果表明:(1)微生物总数、细菌数量的季节动态为:春季>夏季>秋季>冬季,放线菌数量的季节分布为秋冬季多于春和夏季,真菌数量的季节动态为夏季达到最高值,其他季节变化不显著。(2)微生物数量的垂直分布总体上表现为随土层加深而逐渐减少,表层土壤(0-10cm)微生物数量是下面3层(10-40cm)的1.05-9.79倍。(3)土壤微生物根际效应明显,且细菌>真菌>放线菌,R/S值介于1.16-3.76之间。微生物根际效应的季节变化为春、夏季高于秋和冬季。(4)微生物分布与水热等环境因子密切相关,细菌数量与水热组合条件共同作用有关,真菌受温度影响较大,放线菌对土壤水分含量变化较敏感。

Seasonal dynamics of microorganism in rhizospheric soil of Artemisia ordosica in Ordos sandy land

Seasonal dynamics and vertical distribution of microorganism in rhizospheric soil of Artemisia ordosica and the evironmemtal factors were studied in Erdos sandy land.The results obtained were as follows:(1)The seasonal dynamics of the total microorganism and bacteria were spring>summer>autumn>winter.The actinomycetes in autumn and winter were more than that in spring and summer.Fungi reached the highest value in summer and there were no obvious changes in other seasons.(2) Vertical distribution of microorganism were abated as the soil depth increased,the number was much higher within 0-10cm than that within 10-40cm(1.05-9.79 times).(3) The rhizosphere effect was significant,and was shown as bacteria>fungi>actinomycetes.The value of R/S was 1.16-3.76,and the values of R/S in spring and summer were higher than that in other seasons.(4)Microbial distribution was closely related to the heat and moisture distribution.Bacteria were influenced by both soil water content and temperature,fungi were greatly influenced by temperature,and actinomycetes were sensitive to soil water content.