不同利用方式下棕壤及其各级微团聚体中微生物量碳、氮的变化

The Changes of Microbial Biomass C, N in Brown Soil and Several Different Particle Fractions of Microaggregates Extracted from It of Different Land Use Types

采用熏蒸-提取法研究了耕地、园地、林地三种利用方式下棕壤及其各级微团聚体中微生物量碳、氮的变化。研究结果表明:(1)不同利用方式下棕壤微生物量碳、氮的变化趋势均为<10μm微团聚体>原土>10￣50μm微团聚体>50￣250μm微团聚体,且经方差分析可知,除原土与10￣50μm微团聚体中微生物量氮含量差异不显著外,均达到显著或极显著水平。不同利用方式之间微生物量碳、氮含量为林地>园地>耕地,土地利用方式对微生物量碳、氮含量有极显著的影响。(2)微生物量碳/有机碳、微生物量氮/全氮的比值表现为原土及<10μm、10￣50μm微团聚体中均为林地最低,不同利用方式下土壤有机质输入的质的差别造成了这一结果。

Soil microbial biomass C, N in brown soil and several different particle fractions of microaggregates extracted from it of different land use types were studied with the fumigation-extraction method. The results show： （1） The contents of microbial biomass C, N in brown soil keep in the same trend, 〈10μ m 〉the original soil〉10-50μ m〉10-250μ m. With multiple comparison of it, except the difference between the original soil with the 10-50μ m microaggregates, others difference is obvious evidently. Soil microbial biomass C, N in forestland is the highest, which in cultivated land is the lowest. The effects of the different land use types to the contents of microbial biomass C, N were significant. （2） The ratios of BC/TC and BN/TN of original soil, 〈10μ m, 10-50μ m in natural forest was lowest. The organic matter input of different land use types is difference of qualities, which cause the result.