Soil Microbial And Enzyme Activities Of Farmland And Woodland In The Northeast Ulan Buh Desert

In order to explore the biological property of farmland and woodland in the northeast sandy area of Ulan Buh Desert, In this paper, take the desert land as the comparison. the soil bacteria, actinomycetes, fungus and sucrase, urease, catalase, alkaline phosphatase, protease, polyphenol oxidase, cellulase activities of 4 kinds of typical farmlands and 9 kinds of typical artificial woodlands in 0²0, 20⁴0 cm soil layers in the northeast of Ulanbuh Desert have been studied.In combination with correlation analysis and principal component analysis method, Has carried on the appraisal to the farmland and the woodland soil ecology fertility quality . this can provide a theoretical reference for agriculture and planting trees .The main conclusions are as follows:1. Microorganism magnitude: bacteria(107)> actinomycetes(105)>fungi(103). the number of microbes and soil respiration under the seed watermelon farmland was most. The total number of soil microbial and respiration decreasing with the soil depth increased. the activities of soil invertase,urease and alkaline phosphatase under alfalfa farmland were higher than those of others.Soil catalase activity of corn farmland was highest, soil protease activity under seed watermelon farmland was relatively high. cellulase activities of sunflower farmland were higher than those of others.Invertase, urease, protease and cellulase activity decreased with depth, of which the largest decline is invertase activity. Catalase activity is shown as increasing with depth. Alkaline phosphatase and polyphenol oxidase does not show regular with depth.2.In the study area microorganism magnitude: bacteria(106)> actinomycetes(105)>fungi(103). In the 0⁴0 cm soil layer, The number of microbes in the surface layer was maximum, and clearly decreased with the soil depth. The bacteria numbers under Caragana korshinskii Kem. Elaeagnus angustifolia L.and Hippophae rhamnoides Linn.were most in 0⁴0cm soil layer. The actinomycetes under P. gansuensis numbered most, The fungi numbers under Hedysarum scoparium Fisch. and Caragana korshinskii Kem. were bigger than those of others.The number of microbes under the bush forest land was more than under the tree forest land. And they significantly different between the microorganisms. All levels of the forestland soil respiration were higher than control. Except that Populus and Robinia, the remaining surface soil respiration were higher than the lower. Where the average Elaeagnus angustifolia and Hippophae forest soil respiration is higher than other woodlands.in 0⁴0cm soil layer, the activity of soil invertase under P. gansuensis was higher than those of others. the activities of soil urease and catalase under Populus simonii×(Populuspyramidalis +Salixmatsudana)cv. Poplaris'were highest. Soil alkaline phosphatase under Hippophae rhamnoides Linn. and Elaeagnus angustifolia L. were relatively high. P. alba L.var. pyramidalis Bunge, Populus simonii×(Populuspyramidalis +Salixmatsudana)cv. Poplaris'and Hedysarum scoparium Fisch.have higher protease activity; polyphenol oxidase activity was highest under P. gansuensis .In study region, the soil enzyme activities had obvious vertical distribution characteristics, decreasing with the soil depth except the soil catalase and polyphenol oxidase. especiallysoil urease had the sharpest decrease.3. Invertase, urease, catalase, alkaline phosphatase, protease and cellulase enzyme activities and organic matter has a good linear relationship, also these 6 kind of enzyme activities increased along with the soil organic matter content increase, which of the largest increase is urease activity, followed by catalase activity, the smallest increase is alkaline phosphatase activity. Polyphenol oxidase activity was decreased with increasing organic matter content.4. Between the Bacteria, actinomycetes and fungi is the significant or very significant positive correlation; bacteria and actinomycetes only with protease correlation coefficient was significant, while fungi and invertase, urease and protease were significant positive correlation; The invertase displays the highly consistent parallel relations with between the alkalinity phosphatase and the protease, the correlation coefficient respectively is 0.681 and 0.684, achieved remarkable level. Between the urease and the protease, the invertase the correlation coefficient respectively is 0.734, 0.957, respectively achieved significant, very significant; polyphenol oxidase and catalase than among highly significant positive correlation was outside, with the rest of the enzyme activity had significant negative correlation. Cellulase and invertase activity reached a very significant positive correlation with catalase highly significant negative correlation.5. Study area various farmlands soil synthesis principal components value is in turn: alfalfa (F_MX = 2.791)> sunflower (F_KH = 2.687)> Corn (F_YM = 2.499)> seed watermelon (F_ZG = 0.289). Various forest lands soil synthesis principal components value is in turn: Populus simonii×(Populuspyramidalis +Salixmatsudana)cv. Poplaris'(F_XMH=4.354)> Elaeagnus angustifolia L. (F_SZ=0.809)> P. gansuensis (F_EBY=0.453)> Hippophae rhamnoides Linn. (F_SJ=0.295)> Caragana korshinskii Kem. (F_NT=0.077)> Robinia idaho (F_XHH= -0.398)> P. alba L.var. pyramidalis Bunge. (F_XYJ= -0.700)> Hedysarum scoparium Fisch. (F_HB= -2.021)> Tamarix chinensis Lour.(F_CL= -2.862).