Research The Structure And Spectral Characteristics Of Humus Substance From Black Soil In Heilongjiang Province

Black soil degradation threatening food security in China. Soil organic matter has important significance to the promotion of soil fertility, and humic substances is an important part of soil organic matter. Our researches focused on four typical black soil regions in Heilongjiang province, including Beian, Hailun, Binxian and Shuangcheng. To test the contents of different area farmland black soil humus substance and the change of the optical properties of humus components. And extract the regional soil fulvic acid, analyzing the ultra violet spectrum, fluorescence spectrum characteristic. The results were as follows:(1) Contents of different area farmland black soil humus substance composition.In general, the contents of humic substances was reduced gradually in Beian, Hailun, Binxian and Shuangcheng four farmlands, so was the degree of humification.(2) Optical properties of different area farmland black soil humus components.For the optical properties of black soil humus components among different area farmlands,the results showed that absorption spectrum cur ve of components of soil slope(E4 / E6) and tonal coeffic ient(delta Lgk) presented a trend of increase among Beian, Hailun, Binxian and Shuangcheng farmlands. This indicated the a verage relative molecular weight of soil humic substances components reduced in turn, the complexity of molecular decreased, molecular condensation degree decreased, degree of aromatic ity and of humification were both decreased.(3) Ultra violet spectral characteristics of area different farmland black soil fulvic acid.From the parameters of SUVA254, SUVA280, E2/E6, E250/E365, E300/E400, E253/E220, E253/E20,we once again demonstrated that the degree of humification was decreased in Beian, Hailun, Binxian and Shuangcheng four farmlands in different regions in Heilongjiang Province.(4) Fluorescence spectral characteristics of different area farmland black soil fulvic acid.From the two-dimensional fluorescence spectral characteristics(f450/500, I436/I383, AFLR, AHLR, AFLR/AHLR),the degree of humification was decreased in Beian, Hailun, Binxian and Shuangcheng four farmlands in different regions. There-dimension fluorescence spectral characteristics and paralle l factor analysis of different area farmland black soil fulvic acid showed each region between each component was given priority to C1 component(66.85%-77.95%) and C2(22.15%-33.15%) as auxiliary compone nts, which C1 presented the portions of Bioava ilable components and C2 were the sources that were not easy to be using by the terrestrial humic substances.