Study On The Relationship Between Humic Substances And Bioavailability Of Lead In Root Zone Of Tea Plants

With the increasing environmental pollution, the problem of tea quality is getting worse and worse. The excessive lead in tea has become one of the main factors that constrain the development of tea production. It have been studied that the soil is the main source that courses lead pollution of tea, and the control of lead contamination in tea garden is of great significance for the solution of tea lead contamination problem, which also have practical significance for the safety of other agriculture products.In this article, eight soil samples from eight tea plants were employed as research object, which are collected from the tea garden in Zhejiang University. The developed method, Kumada, was used to extracted humus, and the concentration of carbon is determined by Potassium dichromate-Spectromphotometry method. According to our previous analysis of thecontent of lead in different variety of tea plant root soil, it is found that there was little variation among the content of total organic carbon and humic acid of eight different soil samples, while the content of water-soluble substance, fulvic acid and humin show significant differences, and the content of humus composition was significantly correlated with the content of exchangeable lead and old root. The correlation between the content of soluble humus and the content of tea lead is positive.The research results can provide scientific basis for the control of tea plant root bioavailability lead, and have a meaning of guidance for the improvement of tea product quality.