Analysis Of Spatial Heterogeneity Of Soil Heavy Metals In Tea Garden Based On Township Scale

High quality agricultural land produces high quality agricultural products and the quality of farmland is determined by the quality of soil environment.Only by maintaining a stable and healthy soil environment can we ensure the quality of agricultural land and ensure the quality of agricultural products.At present,the quality of farmland soil environment is not optimistic in general and the pressure of farmland protection is great.So,the research on it can help us further understand the current situation of soil environment in our country,and provide a theoretical basis for the scientific construction of farmland quality protection system,and provide practical reference for the rational utilization of farmland and the steady improvement of the quality of farmland.Based on the results of previous studies,taking the Jiangsu and Zhejiang high quality tea growing regions as examples,in this paper,by means of the descriptive statistics,pollution index evaluation model and Kriging spatial interpolation,a preliminary determination of the actual status of soil heavy metals in tea gardens is firstly made through the field investigation and analysis of quality detection.And then,the concentrations of heavy metals of soil tea from two dimensions of "quantity" and"space" were analyzed,so as to find out their rule and reveal the reason,by introducing Copula function model,coupling degree/coupling coordination degree model and standard deviation ellipse model.Finally,according to the research conclusions,some suggestions and measures were put forward to improve the quality of tea garden soil environment,and to improve the quality of tea and to improve the efficiency of land use in tea garden.The results of the study are as follow:(1)The overall level of the concentrations of the heavy metals in tea garden soil in Jiangsu and Zhejiang provinces basically statisfied the standard of soil environmental quality,and the pollution index showed that the pollution level of the soil heavy metals in tea garden in the study areas is in a clean state,and there is no pollution problem.But in some local areas such as Tianmuhu,Dongshan and Longjing,the Zn concentrations in soil exceeded the national standard.Although the degree of exceeding the standard is only 4.30%and 11.21%,2.41%,the relative rates were more than 50%.To avoid further deterioration and the increase in heavy metal pollution tea gardard,more attention should be paid attention to prevent.(2)The correlation of Cu-Zn,Cd-Se,As-Se in tea garden soil is significantly positive,showing a certain synergistic effect,and had a positive trend of enhancement.Meanwhile,heavy metals in tea garden soil and tea showed strong coupling effect in both quantity and space.Therefore,strengthening the regular detection and control of heavy metals in tea garden will improve the quality of tea soil and improve the quality of tea.(3)The heavy metals in the tea garden in two provinces showed strong spatial autocorrelation,and had the characteristics of connecting slices and of the trend along certain directions.At the same time,influenced by the interaction of structural factors and random factors,the spatial distribution of soil heavy metals in tea garden is not only globally similar,but also locally different.So,dealing with the related problems,we should pay attention to the global trend and the local difference.(4)In order to improve the quality of tea garden soil environment and improve the efficiency of garden land use,we think it is necessary to manage and control the soil environment of tea garden,strengthen the early warning,and improve the supervision and quality of the soil environment of the tea garden from the improvement of the planting pattern,the government support and the cultivation of professional talents.