The Research On Soil Anti-Erodibility Of Eucalyptus Plantation In Rare Earth Tailings Area

Soil anti erodibility is important to the development of soil and water conservation. It is the important content of the soil erosion, At present, most studies focused on the Loess Plateau, studies on the Southern Red soil is less, more less for the soil anti erodibility of Eucalyptus plantations on rare earth tailings mining area. This study chosen one year old, two year old,one-year sprout Eucalyptus plantation and open space for the control as the research object on rare earth tailings mining area in Ganxian country Jiangxi Province. Analysised and studied the factors affecting the anti erodibility and gave a more comprehensive assessment of rare earth tailings mining area after vegetation retoration.(1)The study selected four categories and sixteen indicators to analysis by using principal component analysis, and had chosen7as the best indicators to reflect the soil anti erodibility on rare earth tailings mining area. They were X1、X2、X4、X7、X9、X12、 X14. The soil anti erodibility equation to the area is:Y=0.603Y1+0.272Y2+0.126Y3。(2) There are difference on soil anti erodibility between different forest age of Eucalyptus plantation on rare earth tailings mining area. Composite score on annual eucalyptus of anti erodibility were higher than two years old eucalyptus, one-year sprout Eucalyptus plantation and open space, soil anti erodibility index were:two years old eucalyptus> annual eucalyptus>one-year sprout Eucalyptus plantation>open space.(3) Selecting sixteen indexes and soil anti erodibility index to correlation analysis,we found that aggregate, water stable aggregates and clay indexes were significant or extremely significant correlation to soil anti erodibility index. Dispersion and structure coefficients were significantly correlated to soil anti erodibility index.>0.25mm aggregate destruction rate, dispersion coefficient and dispersion rate were negatively correlated to soil anti erodibility index.>0.5mm water stable aggregate content and>0.25mm water stable aggregate content were significantly correlated. Dispersion coefficient and dispersion rate of microaggregate class were negatively correlated to soil anti erodibility, aggregation degree and structure coefficient were significantly correlated.<0.05mm clay content,<0.001mm clay content of inorganic clay class and structural particle index were significantly correlated, while organic matter was not obviously correlated.(4) By analyzing the correlation between the physical and chemical properties of soil,roots and microbial with soil anti erodibility, we can draw that the bulk density,organic matter, bacteria and fungi content were the factors to soil anti erodibility on rare earth tailings mining area, while soil porosity, aggregate saving chance, pH value,N、P、K content and characteristics of roots were not significantly correlation.(5) With the principal component filter out X1(x1), X2(x2), X4(x3), X7(x4), X9(x5), X12(x6), X14(x7) this indicators as independent variable, to soil erodibility index y as the dependent variable, soil erodibility model equation in the rare earth tailings mining area is:y=0.309×1+0.038x2-0.161x3-0.643x4+0.491x5-0.0328x6+0.129x7+41.637The equation derived factors significantly related to and the model fits well.