单施和配施有机物料对沙化土壤微生物群落功能多样性的短期影响

Short term response of microbial community functional diversity in desertified soils under fertilized individual and mixed organic materials

为探讨施用有机物料对宁夏沙化土壤的改良效果,以当地易得的杨树枝条、玉米秸秆、牛粪为原料在2015年4~10月期间进行桶栽试验,采用Biolog技术研究了有机物料单施和配施对宁夏沙化土壤微生物群落功能多样性的短期影响。结果显示:(1)施用有机物料使土壤微生物利用碳源总量增加,微生物代谢活性增强。其利用比例较高的碳源类型为氨基酸类、胺类和碳水化合物类。(2)单施有机物料比配施有机物料对微生物代谢的促进作用强;单施杨树枝条粉碎物的土壤微生物平均颜色变化率在所有处理中最大,而且微生物各种多样性指数也有明显提高。(3)对各类碳源的利用强度与土壤易氧化有机碳、全氮含量和碳氮比之间表现出了密切的关系,微生物多样性指数则与土壤易氧化有机碳和无机氮存在紧密联系。本研究表明,土壤施入杨树枝条粉碎物后微生物代谢活性增强、土壤质量提高,对土壤改良有积极作用。

In order to explore organic amendment effect on desertified soil in Ningxia,a microcosm experiment was set up in April to August 2015. Poplar branch,corn straw and cow manure were selected as fertilized materials,and the short response of microbial function diversity of amended soil with individual and mixed organic materials were tested by Biolog method. Results showed：（1）total amount of carbon sources utilized by microbes in all fertilized organic materials soil increased during the incubated time,and the main types of carbon sources utilized were amino acids,amine and carbohydrate.（2）The microbes in soil fertilized individual organic materials utilized more carbon sources than the microbes in the mixed organic materials. Moreover,fertilized popular branch had the highest AWCD and diversity indices.（3）There were significant correlations between easy oxidized organic carbon,total nitrogen,C/N and different carbon sources utilized by microbes. However,significant correlations were found between easy oxidized organic carbon,inorganic nitrogen and soil microbial diversity index. The study showed that the microbial metabolic activity was enhanced and the soil quality was improved after poplar branch was put into desertified soil,which had positive effect on the soil improvement.