新疆玛纳斯河流域不同垦殖年限农田耕层土壤微生物群落特征

目的]研究垦殖对农田耕层土壤微生物群落特征的影响.方法]采用常规计数法对新疆天山北坡玛纳斯河流域两组不同垦殖年限(0～200年和0～20年)绿洲农田耕层土壤微生物区系和细菌生理菌群多样性进行研究.结果](1)荒地一经开垦耕种,微生物数量高于荒地.(2)随着垦殖年限的延长,耕层土壤细菌和放线菌数量总体呈上升趋势,真菌则先增加后减少;多样性指数都表现出先增加后减少的趋势.(3)随着垦殖年限延长,土壤细菌生理菌群的数量均呈先增加后降低的趋势,多样性指数的变化规律不明显.结论]垦殖50年后,土壤微生物种群趋向单一,有益生理菌群数量减少,农田土壤生物肥力总体呈下降趋势.

Characteristics of Microbial Community in Surface Soil with Different Reclamation Years in Manas River Basin of Xinjiang

【Objective】The purpose of this experiment was to study the effect of reclamation on characteristics of soil microbial communities in farmland plough layer.【Method】Using conventional counting method,the diversity of microbial flora and bacterial physiological groups in the soil with two groups of different reclamation years(0-200 years and 0-20 years) were studied in oasis farmland in Manas River basin of Xinjiang.【Result】(1)The microbial number had generally increased after reclamation of waste land.(2) The bacterial and actinomycetes number in surface soil had generally increased,while the number of fungi had first increased and then decreased with years of use.However index of microbial community diversity had first increased and then decreased.(3) With years of use,the number of bacterial physiological groups had first increased and then decreased,but index of community diversity had not obvious the changing tread.【Conclusion】After reclamation of 50 years,soil microbial communities became simplified,the number of useful bacterial physiological groups decreased.The biological fertility of farmland soils generally showed a tendency of decrease.