不同轮牧方式下宁夏荒漠草原土壤生物学性状变化及土壤健康评价

发布时间：2018-05-24 23:34

本文选题：轮牧方式 + 荒漠草原　；参考：《宁夏大学》2015年硕士论文

【摘要】：以宁夏荒漠草原为对象,研究围栏禁牧和滩羊连续放牧、二区、四区和六区轮牧土壤微生物和酶活性变化,分析土壤微生物、酶活性、理化特性间的相关性,进行了放牧草地土壤健康评价。结果表明：(1)在禁牧和连续放牧、二区、四区和六区轮牧下,土壤微生物以放线菌为主,细菌次之,真菌最少。在0-30cm土层,六区轮牧的微生物总数、放线菌、细菌最大,四区轮牧次之,连续放牧最小。随着土层加深,微生物总数量呈下降趋势。土壤结皮中,微生物总数量在二区轮牧最大,真菌和细菌数量以连续放牧最高,放线菌数量以二区轮牧最多。(2)不同轮牧下微生物量碳、氮含量差异极显著(P0.01)。0-30cm土层微生物量碳以六区轮牧最大,微生物量氮以四区轮牧最大。随土层深度加深,微生物量碳、氮含量呈下降趋势。微生物量碳层化现象在围栏禁牧小区明显。土壤结皮微生物量碳含量以连续放牧最高,微生物量氮含量以四区轮牧最高。(3)酶活性的在轮牧方式间存在极显著差异(P0.01)。六区轮牧的脱氢酶活性、脲酶活性最高,转化酶和过氧化氢酶活性在二区轮牧中最高,连续放牧的磷酸酶活性最高。随着土壤深度加深,酶活性呈下降变化(P0.01)。(4)土壤容重在围栏禁牧区最大,连续放牧最小。毛管孔隙度和土壤含水率最高,六区轮牧次之,围栏禁牧最小。土壤粉粒含量在连续放牧区最大,细砂粒在四区轮牧最大,中砂粒和粗砂粒在围栏禁牧最大。土壤结皮总盖度在围栏禁牧最大,六区轮牧次之,连续放牧最小。土壤全氮在连续放牧最大,二区轮牧次之,四区轮牧最小。土壤有机质在六区轮牧最大,二区轮牧最小。碱解氮在围栏禁牧最大,连续放牧最小。速效磷在连续放牧最大。(5)土壤生物学特性与土壤理化性状之间存在一定的相关性。过氧化氢酶与微生物量碳有极显著的强相关关系。放线菌与脲酶和微生物量碳有极显著的正的强相关关系,容重与磷酸酶有极显著的负相关关系。速效磷与磷酸酶和过氧化氢酶有极显著的正的强相关关系。速效钾与微生物量碳和真菌有极显著的正的强相关关系。(6)通过主成分分析法和隶属函数分析法评价结果,土壤健康状况表现为六区轮牧四区轮牧二区轮牧围栏禁牧连续放牧。
[Abstract]:Taking the Ningxia Desert Steppe as the object, the changes of soil microorganism and enzyme activity in two, four and six regions were studied, and the correlation between soil microorganism, enzyme activity and physicochemical properties was analyzed. The soil health evaluation of grazing grassland was carried out. The results showed: (1) in the grazing and continuous grazing, two area, four zone and six area. Under the rotational grazing, the soil microbes were mainly actinomycetes, the bacteria were second and the fungi were the least. In the 0-30cm soil layer, the total number of microbes in the six regions, the actinomycetes, the bacteria were the largest, the four regions were grazing the second, and the continuous grazing was the smallest. As the soil layer deepened, the total number of microbes decreased. The total number of microbes in the soil crust was the largest in two regions, fungi and fine. The number of bacteria in continuous grazing was the highest, and the number of actinomycetes in the two region was the most. (2) the microbial biomass carbon under different rotational grazing was very significant (P0.01) the microbial biomass carbon in the.0-30cm soil layer was the largest in the six region, and the microbial biomass nitrogen was the largest in the four region. The soil microbial biomass carbon content was the highest in the continuous grazing area, and the microbial biomass nitrogen was highest in the four region. (3) the enzyme activity was significantly different between the rotational grazing methods (P0.01). The activity of dehydrogenase, the highest urease activity, and the invertase and catalase activity in the two region were the highest in the six region. The highest activity of the phosphatase was the highest in the continuous grazing. As the depth of the soil deepened, the activity of the enzyme decreased (P0.01). (4) the soil bulk density was the largest in the forbidding pasture area, and the continuous grazing was the smallest. The porosity and water content of the soil were the highest, the six region was the highest and the enclosure was the smallest. The soil powder content was the largest in the continuous grazing area, and the fine sand grains were four. The maximum soil crusts and coarse sand grains in the enclosure are the largest. The total soil cover coverage is the largest in the fence, the six region is the largest grazing, and the continuous grazing is the smallest. The soil total nitrogen is the largest in continuous grazing, two in the four region and the lowest in the four region. The soil organic matter is the largest in the six region and the two region is the smallest. The alkali hydrolysable nitrogen is the largest grazing prohibition in the fence. Continuous grazing was the minimum. (5) there was a certain correlation between soil biological characteristics and soil physical and chemical properties. There was a significant strong correlation between catalase and microbial biomass carbon. Actinomycetes had a very significant positive correlation with urease and microbial biomass carbon, and the bulk density and phosphatase were extremely significant negative. There is a very significant positive correlation between available phosphorus and phosphatase and catalase. There is a strong positive correlation between available potassium and microbial biomass carbon and fungi. (6) the results of evaluation by principal component analysis and membership function analysis show that the soil health status is now in the two district rotation grazing fence in District Four rotation grazing. Pastoral grazing.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

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