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【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。
【Objective】 The objective of this study was to investigate the effects of reclamation on soil microbial community characteristics in topsoil. 【Method】 Two groups of topsoil microbial flora and bacterial community diversity under different cultivation years (0 ~ 200 years and 0 ~ 20 years) in Manasi River Basin on the north slope of Tianshan Mountains in Xinjiang were studied by conventional counting method . 【Result】 (1) Once the wasteland was reclaimed and cultivated, the number of microorganisms was higher than that of wasteland. (2) With the increase of reclamation age, the amount of soil bacteria and actinomycetes in tillering soil generally increased, but the fungi increased first and then decreased; the diversity index showed the trend of increasing firstly and then decreasing. (3) With the extension of reclamation years, the number of bacterial communities in soil increased at first and then decreased, but the variation of diversity index was not obvious. 【Conclusion】 After 50 years of reclamation, the population of soil microorganism tended to be single, the number of beneficial physiological bacteria decreased, and the overall soil biological fertility of farmland decreased.