Proton Release From Tea Roots And Amelioration Of Tea Garden Acidification Soil

As the tea plant’s metabolism, man-made inappropriate management and environmental degradation and so on, tea garden soil acidification is more and more severe, tea garden in which soil pH value is less than4.0are increasing, they have become a worldwide problem of tea production. In this paper, expand tea plant root exudates of designing different aluminum concentration and the proportion of different nitrogen forms, mensurate the amount of organic acids and H+of tea plant root secretion and cation absorption rate, in order to explore effects on the tea plant root exudates on tea garden soil acidification. On the serious soil acidification phenomenon, the paper desined the method of improving soil pH value, experiment soil incubation, investigated the amelioration effect of different plant materials and dicyandiamide on soil acidification.0,100,250,500μmol/L Al3+Concentration levels, compared with the initial pH value, the pH value of tea plant hydroponic nutrient solution reduced. The tea plant roots released certain organic acids and H+, when concentration level is250μmol/L, the absorption rate of aluminum was highest. NH4+:NO3-=0:4,1:1,2:1,3:1,4:0, tea plant absorbed ammonium nitrogen, released H+; absorbed nitrate nitrogen, released OH", pH value was also fluctuant. When NH4+:NO3-=3:1, the nitrogen absorption rate is higher. With the pH was constant, the proton release was more significantly than the non-constant pH conditions. When the Al3+concentration were0,100,250μmol/L, set pH:5.0and pH:4.5, aluminum absorption rate of the former was larger significantly than latter(P<0.05).This article was designed seven treatments, Chinese milk vetch shoots, Chinese milk vetch shoots and dicyandiamide, black locust leaves, black locust leaves and dicyandiamide, pea straw, pea straw and dicyandiamide. The control was tea garden red soil without plant materials and dicyandiamide. The results showed that the addition of the plant materials increased soil pH to some extent compared with control. The rise extent of soil pH was bear on the amount of ash alkalinity and nitrogen in the plant materials. The more the ash alkalinity in plant materials, the greater the increase in soil pH. The treatments appended dicyandiamide maintained a higher pH. Nitrgen transformation affected the amelioration effects of these plant materials on soil acidity. The mineralization of organic N from plant materials consumed H+and increased soil pH. While the nitrification of NH4+-N from the mineralization of organic N released H+and decreased soil pH, which reduced the final amelioration of plant materials on soil acidity to some extent. Dicyandiamide inhibited nitrification and maintained an improved effect. The addition of the plant materials or the plant materials and dicyandiamide increased soil exchangeable base cations and decreased the soil exchangeable Al(P<0.05).Then designed six treatments of the above, the later article planed tea garden yellow brown soil as the control. The results showed that the addition of the plant materials increased soil pH to some extent compared with the control, the treatments appended dicyandiamide maintained a higher pH. The addition of the plant materials or the plant materials and dicyandiamide increased soil exchangeable base cations and decreased the soil exchangeable Al (P<0.05).