鄂尔多斯南部不同沙地土壤养分含量、酶活性与微生物数量变化规律及其相关性

以内蒙古鄂尔多斯的不同沙地类型(流动沙丘、半固定沙丘和固定沙丘)为研究对象,测定其土壤养分,土壤酶和土壤微生物的含量,期望得到它们的变化规律及其相关性,为该地区的防风固沙提供理论参考。结果如下:土壤酶活性的季节变化和垂直分布均没有显著的规律。碱性磷酸酶在固定沙丘中随土层的增加而降低;在表层土壤中其活性最高;夏季其活性最低。在3样地中细菌数量最多,放线菌次之,真菌最少,固定沙丘>半固定沙丘>流动沙丘。相关分析表明:土壤3大类微生物与有机质、全氮含量和碱性磷酸酶活性均为极显著正相关,与全磷含量、多酚氧化酶和脲酶活性的相关性不显著。细菌和微生物总数与全钾含量呈显著相关,放线菌和真菌与全钾含量的相关性不显著。在流动沙丘和固定沙丘中芽孢杆菌属占细菌的比例在冬季最高,夏季次之。在半固定沙丘中是冬季最高,其次是在春季,这与细菌总数的变化趋势一致。通过形态学观察、生理生化试验、Biolog试验以及分子生物学鉴定结果,得到沙漠中最常见的芽孢杆菌主要有Bacillus cereus、B.licheniformis、B.subtilis、B.megaterium和B.maroccanus。通过该研究客观地反映了内蒙古鄂尔多斯不同沙地类型的土壤肥力状况,从而为该地区沙地土壤改良和防风固沙提供重要的依据。

The Changing Patterns of and Correlation among Nutrient Content, Enzyme Activities and Microorganism Biomass in Different Sandy Soils at Southern

The conditions of soil nutrient,soil microorganisms and soil enzyme activities and their correlation with each other in the three kinds of sandy land(sand-flowing dune,semi-fixed sand and fixed sand) were studied in Erdos in order to provide theoretical basis for wind protection and sand fixation.The results were as follows: the season variation and vertical distribution of the activity of soil enzyme were irregular.In fixed sand,the activity of Alkali phosphatase.was weakened with the soil depth,and was highest under ground 1 cm and lowest in summer.In three plots,the predominant group was bacteria,actinomyces was the next and fungi was the least among soil microbes.The amount of bacteria,actinomyces,fungi and total microbes was all larger in fixed sand than in semi-fixed sand and the least in sand-flowing dune.The amount of soil microorganisms,namely bacteria,actinomyces and fungi,was positively correlated to the content of organic matter and total nitrogen and the activity of Alkali phosphatase,and not correlated to the activity of Polyphenol oidase and Urease.The amount of bacteria and microorganisms was significantly in positive correlation to the content of total kalium,but the amount of actinomyces and fungi was indistinctively correlated to the content of total kalium.In fixed sand and sand-flowing dune,the percentage of bacillus sp.was the highest in winter and the least in summer,and the quantity of bacteria was lowest in the same time.But in semi-fixed sand it was the highest in winter and the second in spring and the quantity of bacteria showed the same regularity.According to physiological-biochemical reaction,morphological characteristics and16S rDNA sequence,Bacillus cereus,B.maroccanus,B.megaterium,B.subtilis,B.licheniformis.were identified as the mail bacillus species in sandlot.This study objectively indicated the conditions of fertility in different sandy soil at Southern Erdos,thereby providing important grounds for soil improvement,wind protection and sand fixation in this region.