The character of microelement contents among different shrubs rhizosphere at the desertification alpine grassland in the Maqu County

Salix oritrepha，Hippophae rhamnoides and Amorpha fruticosa growing in the desertification alpine grassland in the Maqu County were selected to exam the differences of soil microelement and pH value between rhizosphere and norhizosphere. The results of this study indicated that the soil pH values of rhizosphere were significantly lower than that of norhizosphere for three shrubs, and they showed a different degree of soil acidification. The total Fe and Cu contents of rhizosphere were significantly higher than that of norhizosphere for three shrubs, in which H. rhamnoides and A. fruticosa significantly enriched the Fe, and Amorpha enriched the Cu. Except for S. oritrepha, the total Mn content of rhizosphere in other two shrubs was lower than that of norhizosphere. The total Zn content of H. rhamnoides at rhizosphere was higher than that at norhizosphere, while other two species had a higher Zn content in norhizosphere than that in rhizospheres. The available Fe content of A. fruticosa at rhizosphere was higher than that at norhizosphere, however, other two species were lower. The enrichment trend of available Zn was H.rhamnoidesS.oritrephaA.fruticosa. These results suggested that there was a correlation relationship on soil nutrient conditions between rhizospheres and norhizospheres. In the rhizosphere, the total Cu content was positively related to the available Cu content and the total Fe content was positively related to the total Cu and the available Fe content. The available Fe content was positive related to the available Mn content. In the norhizosphere, the total Fe content was positive correlation with the total Cu content.