| Karst ecological system in this paper,some countries field scientific observation station 6 kinds of different ways of land use?paddy field,dry land,garden land,forest land,shrub and grass?soil as the research object,through field investigation and indoor analysis,using chloroform fumigation and improved BCR continuous extraction methods of research?0?20 cm?and the underlying surface?20-40 cm?soil?SOC?,soil microbial biomass carbon?SMBC?and soil soluble organic carbon?DOC?and different forms of calcium?acid soluble calcium,but also square one calcium,calcium can oxidation state,residual state?of the content and distribution of To reveal the relationship between SOC,SMBC and DOC and different forms of calcium under different land use types.The main results are as follows:?1?The SOC contents in the surface and bottom of the six land use types ranged from 14.38 to 38.59g·kg-1and 12.42 to 28.23g·kg-1,respectively,with an average of29.97g·kg-1and 20.02g·kg-1.Woodland was the highest and Return farmland to grassland the lowest,which was represented as:woodland>,shrub>,paddy field>,garden>,dryland>.?2?The SMBC content of the surface layer and the bottom layer of the six land use modes is between 121.36?355.30 mg·kg-1and 102.40 and 228.30 mg·kg-1,Mean219.30 mg·kg-1mg·kg-1,157.52 The highest arbor forest,Drylands are lowest,The results are as follows:Arbor woodland>shrubland>orchard>paddy field>wasteland>dryland and Arbor woodland>shrubland,orchard>Return farmland to grassland>paddy field>dryland;The content of soluble organic carbon in the surface layer and the bottom layer of the six land use modes is between 20.71?40.05mg·kg-1and 14.73?24.25,respectively,Average mg·kg-1,30.83 and 20.59 At the top,paddy fields(40.05 mg·kg-1)were the highest,Return farmland to grassland(20.71mg·kg-1)lowest,shrubbery(24.25 mg·kg-1)highest ground floor,Arbor woodland(14.73 mg·kg-1)lowest,The results are paddy field>Arbor>shrub>orchard>dryland>orchard and shrub>orchard>paddy field,paddy field>wasteland and Arbor woodland;The qMB of this study ranged between 0.50%?1.22%,The top layer is orchard,1.22 per cent,Drylands are lowest,0.50%,The highest understory is shrubbery,0.89%,The lowest paddy field is 0.50;Correlation analysis shows that,The SMBC and SOC of surface layer and bottom layer are positively correlated.?3?The total contents of four types of calcium in surface soil of paddy field,upland,garden,woodland,shrub and Return farmland to grassland are respectively:7.02 g·kg-1,10.91 g·kg-1,0.68 g·kg-1,8.42 g·kg-1,6.73g·kg-11 and 3.77 g·kg-1,among them,state of acid soluble calcium content of the highest rates of calcium form,about60%,but also square one calcium content of the calcium ratio is higher,about 25%,calcium can oxidation state and residue calcium added up to less than 20%,in the form of calcium in the form of four different calcium content is high and low order for calcium acid soluble state>is square one>calcium calcium residue state>calcium oxidation state,land use type affects the content of calcium morphology,but has no effect on the proportion of each morphology.The average content of the underlying soil calcium form below the surface,but its distribution is similar to the surface.?4?In the surface soil,SOC state and acid soluble calcium was significantly positive correlation,and residue were very significant positive correlation of calcium,and calcium and calcium can also types and oxidation state there is no significant correlation,SMBC and residual state calcium was significantly positive correlation,and acid soluble calcium,but also types of calcium and calcium oxide state there is no significant correlation,and in the underlying soil,SOC and oxidation state and residue calcium calcium was significantly positive correlation,and acid soluble calcium and calcium can also square one there is no significant correlation,SMBC and oxidation state calcium and create a significantly positive correlation,There was no significant correlation between acid soluble calcium and reducible calcium.There was no significant correlation between the surface and bottom DOC and the four forms of calcium. |
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