Ginseng Allelochemicals’ Impact On Soil Enzyme Activities And Microbial Diversity, As Well As Ginseng Allelochemicals’ Mobility In Soil

In this experiment, ginseng’s primary allelochemicals, including ginseng saponins. syringic acid, vanillic acid, coumaric acid and ferulic acid, of various concentrations have been added into soil. Soil enzyme activities are thereafter tested once every30days. The experiment has applied the method of BIOLOG to test the impact of ginseng’s primary allelochemicals on the functional diversity of soil microorganism, and applied the combined methods of soil thin layer chromatography and biometric technology to test the migrational mobility of these allelochemicals in soil. The study about the impact of ginseng allelochemicals on soil enzyme and the functional diversity of soil microorganism plays a significantly positive role in the research of the ginseng soil sickness and the provision of an effective improvement scheme. The aim of this thesis is to provide a theoretical foundation for the improvement of the old ginseng soil. The experimental results are shown as follows:1. The study about the impact of ginseng’s primary allelochemicals on soil enzyme activitiesAll of ginseng’s primary allelochemicals have inhibitory effect on soil protease, soil polyphenol oxidase, and urease enzyme. The soil protease activity was7.0372±0.23,19.13%inhibition rate compared with the control under0.1mg/mL syringic acid after90days. The soil polyphenol oxidase activity was0.2502±0.01,19.34%inhibition rate compared with the control,under0.1mg/mL saponins after30days. Under0.1mg/mL incensebean acid after60days, the soil urease activity was0.1497±0.04and inhibitionrate reaches maximum of39.61%compared with the control. The allelochemicals promote the activity of soil acid phosphatase, training60days with O.Olmg/mL saponins the soil acid phosphatase activity was1.2947±0.06,31.12%. maximum promotion compared with the control. Ginseng saponin as the main allelochemical of ginseng significantly inhibitted other soil enzymes compared wth the control. The allelochemicals of phenolic acids monomer have effect on soil enzyme activitiesbut not significantly.2.The study about the impact of ginseng’s primary allelochemicals on the function of soil microorganism.Ginseng allelochemicals have different AWCD value with different length of cultural time. During the span of0-10days, the AWCD value of the curve is higher than the control. The span of cultivation is10-20days when using different kinds of acid. The changing curve of AWCD value with ferulic acid of different concentrations is lower than control in average. The span of cultivation for all different allelochemicals is between20-30days, control AWCD value is in the middle of AWCD values of microorganism in the soil which is treated by different concentrations of ferulic acid. The span of cultivation for all different allelochemicals is within the timeframe of30-40days, the AWCD curve does not show a strong regularity.In general, ginseng’s primary allelochemicals present inhibition to Simpson diversity index, Shanon index, the Brillouin index and McIntosh index. They do not show any significant link with the concentrations of allelochemicals. Microorganisms in different types of soil possess different carbon utilization mode. Different concentrations of acid treatment10days of the soil, the contribution of the first principal component PC1was44.24%, the contribution of the second principal component PC2was14.08%; different concentrations of acid treatment of the soil in20days, which the contribution of the first principal component PC1was54.70%, the contribution of the second principal component PC2was14.15%; different concentrations and different kinds of acid treatment of the soil in30days, including the contribution of the first principal component PC1was35.02%, the contribution of two principal components PC2was15.36%; different concentrations of different kinds of acid treatment of the soil in40days, the contribution of the first principal component PC1was53.20%, the contribution of the second principal component PC2was14.84%.3.The study of the migrational mobility of ginseng’s pramary allelochemicals in the soilDifferent allelochemicals result in different migrational performance in the same soil, allelochemical migration in the soil less than the value of Rf. In the same concentration, the migration of five kinds of allelochemicals are basically the same in the soil:saponins> vanillic acid> ferulic acid> syringic acid> coumaric acid; but the values of Rf are different with the order of specific migration which were relevant to the same kinds of allelochemicals at different depths in the soil, that are as follows:saponins0.01mg/mL> saponin0.1mg/mL>saponins1.0mg/mL.With the concentration increased, values of Rf were decreasing, which saponins1.0mg/mL was minimum(0.4278). Syringic acid1.0mg/mL> syringic acid0.01mg/mL> syringic acid0.1mg/mL, the minimum value of Rf of syringic acid (0.1mg/mL) was0.1516. Vanilla acid (0.01mg/mL)> vanillic acid1.0mg/mL> vanillic acid0.1mg/mL, the Rf values of vanillic acid (0.01mg/mL) was a minimum (0.2757). Ferulic acid0.01mg/mL> ferulic acid the1.0mg/mL> ferulic acid0.1mg/mL, the minimum of Rf values of ferulic acid0.1mg/mL was0.2033.1.0mg/mL coumaric acid> coumaric acid0.1mg/mL> coumarate0.01mg/mL, with the concentration decreasing Rf value decreased, the minimum Rf value of coumarate0.01mg/mLwas0.0991.