Characteristics Of Zinc Forms In Tea Garden Soils At The Dongting Lake Region In Hunan Province

The micro-element zinc in soil play important role for the growth of tea plant and the tea quality.In order to study the activity and efficacy of the zinc in the tea plantation soil,and also to provide the theoretical basis for the reasonable fertilization of the tea plantations at Dongting Lake region and build of the high quality and yield tea plantations.Therefore,taking the soil of Dongting Lake region as main research area,by the method of soil sampling,laboratory analysis and computer technology,the regularity of distribution and zinc forms and its effective factors of tea plantations soil that derived from six main soil parents were studied and discussed.The result showed as the follows:1.The total soil zinc of tea plantations was not too high in the overall level at the Dongting Lake region,its average value is 80.72mg/kg,lower than the Chinese average(100mg/kg).The lowest was higher than the plant critical value,and the highest was lower than the value of toxicity symptom,these showed that the tea plantations didn't exist the conditiong of zinc deficiency at the Dongting Lake region.It was fit for building the Nuisance Free Tea Producing Area to fulfill the growth of tea plant.Soil parent affected observably the distributing of zinc,the highest content of total zinc was the soil that derived from the mauve sandstone in the six main soil parents,its average was 90.05 mg/kg,while the lowest was the soil from river alluvium,its average was 52.66 mg/kg.2.In the distribution and forms of the Zinc,the distribution characteristic of zinc forms was siliceous (47.943mg/kg)＞organic(12.354 mg/kg)＞exchangeable(9.586 mg/kg)＞pleomorphous Fe oxide(5.478 mg/kg)＞amorphous Fe oxide(3.985 mg/kg)＞Mn oxide(1.372 mg/kg) at tea plantations of the Dongting Lake region.The zinc residual fraction was the main form.3.Statistics analysis between all zinc forms and the main element of soil nutrients and heavy metals, the results showed each element affected all zinc forms in a certain degree except the element Ni.In general,the decrease of pH,Cd and N,the increase of soil cation exchange capacity and Pb in soil,were in favor of enhancing the validity of zinc.4.Based on the experiment data,the zinc forms management system that used Delphi7 programming tools as a means of establishment could take a dynamic manage of the zinc contents,and had certain significance on rational fertilization.