盐池县草地沙漠化过程中土壤微生物的变化.docVIP

 盐池县草地沙漠化过程中土壤微生物的变 化# 许冬梅1,2，谢应忠1,2* 5 10 15 20 25 30 35 （1. 宁夏大学 农学院， 银川 750021； 2. 宁夏大学西北土地退化与生态恢复国家重点实验室培育基地， 银川 750021） 摘要：对盐池县潜在沙漠化草地、轻度沙漠化草地、中度沙漠化草地、重度沙漠化草地和极 度沙漠化草地 5 种不同沙化类型草地土壤中 0－5cm 和 5－20cm 土层的细菌、真菌、放线菌 及硝化细菌、好气性固氮菌和纤维素分解菌三个微生物生理群的数量进行了研究。结果表明： 随沙化程度的加重，土壤微生物总量，三大菌数量及微生物各类生理群数量总体呈下降趋势； 除沙化顶级类型草地外，微生物总量，细菌、放线菌数量及各微生物生理群数量均为 0-5cm 高于 5-20cm，而真菌垂直分布表现出与其它菌类不同的特征，在轻度沙漠化草地，真菌数 量为 0-5cm 土层低于 5-20cm 土层，而在极度沙漠化草地则为 0-5cm 土层多于 5-20cm 土层； 土壤微生物总量与土壤粘粒、有机质、全氮、速效氮、速效钾含量均呈极显著正相关。 关键词：草地沙化；土壤微生物；微生物生理群 中图分类号：S812.5 Changes of Soil Microbe during Sandy Desertification for Grassland in Yanchi County Xu Dongmei1,2, Xie Yingzhong1,2 (1. College of Agronomy, Ningxia University, Yinchuan , Ningxia, 750021, China; 2. Breeding Base of State Key Laboratory for Preventing Land Degradation and Ecological Restoration, Ningxia University, Yinchuan, Ningxia, 750021, China ) Abstract: A trail was conducted to reveal the distribution of soil bacteria，fungi，actinomycetes, nitrobacteria, oxygenic azotobacteria and cellulose-decomposing bacteria at 0-5cm and 5-20cm depth in potential desertification grassland, light desertification grassland, medium desertification grassland, severe desertification grassland and extreme desertification grassland in Yanchi. The results showed that: The number of total microbe, bacteria, fungi, actinomycetes, nitrobacteria, oxygenic azotobacteria and cellulose-decomposing bacteria declined from potential desertification grassland to extreme desertification grassland. For the vertical distribution of various groups of microbe, the numbers of bacteria, actinomycetes, total microbe and microbial physiological groups in extreme desertification grassland were 5-20cm0-5cm, in other desertification categories they were all 0-5cm5-20cm. The vertical distribution of fungi was different from other groups of microbe, the numbers of fungi was 0-5cm5-20cm in light desertification grassland and 0-5cm5-20cm in extreme desertification grassland. The numbers of mi