Effects of Different Vegetation on Rhizosphere Soil Microbial Properties in the Hilly-Gully Region of Loess Plateau

In order to explore the effect of revegetation on rhizosphere soil microbial properties in Loess Plateau,the changes of organic carbon(C),microbial biomass C,microbial biomass N,basal respiration and enzymes activities in both rhizosphere and bulk soil of six vegetation types at the Dunshan watershed of Hilly-Gully Region were investigated.Results showed organic C in the rhizosphere soil of Caragana korshinskii,Heteropappus altaicus and Artemisia capillaris was higher than that in bulk soil.The pH in the rhizosphere soil of Astragalus adsurgens,Panicum virgatum,Heteropappus altaicus and Artemisia capillaris was lower than that in bulk soil.With an exception of Hippophae rhamnoides,microbial biomass N in rhizosphere soil of five vegetation types was higher than that in bulk soil.Microbial biomass C in the rhizosphere of Hippophae rhamnoides,Heteropappus altaicus and Artemisia capillaris was higher compared with in bulk soil.All plants showed higher basal respiration and peroxidase in the rhizosphere soil than that in bulk soil.Saccharase,urease,alkaline phophatase and catalase had different change tendency in rhizosphere and bulk soil.Rhizosphere did not have significant effect on polyphenol oxidase.There were positively correlation between soil organic C,microbial biomass C,microbial biomass N,saccharase,urease and catalase.Peroxidase was positively correlated with basal respiration but negatively with polyphenol oxidase.Furthermore,natural grassland(Heteropappus altaicus,Artemisia capillaris) showed higher organic C,microbial biomass N,saccharase,urease,catalase and polyphenol oxidase in the both rhizosphere and bulk soil than artificial shrubland(Caragana korshinskii,Hippophae rhamnoides) and artificial grassland(Astragalus adsurgens,Panicum virgatum).