Soil Biological Characteristics And Soil Fertility Of Shrub Sand-fixing Lands In The Yulin Sand Area

In this study, Caragana korshinskii, Salix psammophila, Artemisia desterorum andSabina vulgaris in the Yulin sand area in Mu Us sandy land had been chosen as researchsubjects. The quantity of soil bacteria, actinomycetes, fungus, and activities of sucrase,catalase, phosphatases, urease and their relationships in0~20cm and20~40cm soil layers infour shrub lands were studied., besides the quantity of soil bacteria, actinomycetes, fungus,and activities of sucrase, catalase, phosphatases, urease in rhizosphere and non-rhizospheresoils of the four species were studied, and the evaluation of the soil fertility for different shrublands will be studied by using the principle components analysis. Main results are as follows:(1) After shrub forests were set up, soil nutrients have been improved greatly, thedistribution of soil nutrients had an obvious hierarchical structure, that the surface was higherthan the lower. The soil nutrients in rhizosphere soils of different shrub forests were higherthan that in non-rhizosphere soils in the0~40cm soil layer. Soilorganic matter(SOM),available nitrogen(AN), available phosphorus(AP) and available kalium(AK) increasedsignificantly compared with drift sand, and that was in the order of C. korshinskii> S.psammophila> A. desterorum> S. vulgaris.> drift sand, soil improvement of C. korshinskiiwas higher than that of the other shrubberies, recommendations will be given priority tonitrogen fixing plants when selecting sand-fixing shrubs.(2) Soil microbial quantity increased significantly after shrub forests were set up, thequantity of soil bacteria> actinomycetes> fungi throughout the whole soil profile, and thequantity of soil microorganisms was in the order of C. korshinskii> S. psammophila> A.desterorum> S. vulgaris.> drift sand. The distribution of soil microorganisms had an obvioushierarchical structure, that was in the order of0～20cm>20～40cm. bacteria dominated insoil microbial community in the rhizosphere and non-rhizosphere soils of four sand-fixingshrubs, the number of soil microorganisms presents obvious rhizosphere aggregation.(3) Soil enzymes activities has increased significantly in different shrub forestscompared with drift land. The activities of four enzymes(sucrase, urease, phosphatases,catalase) were in an order of C. korshinskii> S. psammophila> A. desterorum> S. vulgaris.. The distribution of soil enzymes had an obvious hierarchical structure, and that was in theorder of0～20cm>20～40cm. Soil enzymes activities in rhizosphere soils of differentshrub forests were higher than that in non-rhizosphere soils in the0~40cm soil layer.(4) The quantity of bacteria, actinomycetes, fungi and the activities of four kind soilenzymes (sucrase, urease, phosphatases, catalase) were significant or extremely significantpositive correlated to organic matter, available nitrogen(AN) and available phosphorus(AP),but soil microbial quantity and soil enzymes have no relationship with available kalium(AK).The significant relationships were observed not only among bacteria, actinomycetes, fungi,but also among four kind of soil enzymes activities. Besides, extremely significantrelationship were observed among the activities of sucrase, urease, phosphatases, catalase.(5) The result showed that the comprehensive fertility level of different shrub lands wasin the order of C. korshinskii> S. psammophila> A. desterorum> S. vulgaris, the mostsuitable cultivation species for the construction of sand-fixing shrub of sand area is nitrogenfixing plants. significant relationship were observed among actinomycetes, phosphatases, andsoil nutrients, besides they all have a great impact on first principle component, soilactinomycetes and phosphatases could be the preferred soil microorganism and soil enzymeindicator.