Research Of Tea Production Traceability Technology In A District Scale

In the process of selling tea,there will be phenomena such as shoddy,false and genuine phenomena,which will damage the interests of consumers.Tea is a source of agricultural products,and the content of mineral elements in tea is stable.In order to determine the true origin of tea and standardize the tea market,the origin of tea origin is studied by measuring the content of mineral elements in the soil and tea.The total nitrogen,phosphorus,potassium,available nitrogen,available potassium,available phosphorus,organic matter,pH value,and 12 kinds of mineral elements(selenium,zinc,nickel,manganese,manganese,chromium,lead,magnesium,calcium,aluminum,sodium and potassium)were measured in the tea and the corresponding tea garden soil collected at 74 random sampling points in Lishui District of Nanjing.Content,through correlation analysis,Kriging analysis,cluster analysis,principal component analysis,multiple linear regression and other statistical analysis methods,the difference and homology of different elements of tea and soil were studied,and the regression formula of the characteristic mineral elements of the traceability of tea origin in Lishui district was constructed to carry out the research on the origin of tea origin for theoretical basis.The results of this study are as follows:(1)The content of nitrogen,phosphorus and potassium in the tea garden soil in Lishui is the highest,and the content of potassium is the lowest.The variation coefficient of nutrient content is within 35.0%～193.0%,and there is strong variation in effective nitrogen and available phosphorus content.The content of aluminum and manganese in tea and soil is high,the variation coefficient of mineral elements in tea is 16.1%-84.6%,and the coefficient of variation of soil mineral elements is 22.1%～86.0%.The elements of selenium,manganese,chromium,lead and aluminum in the tea and the elements of nickel,manganese,chromium,lead,calcium and copper in the soil have high coefficient of variation,indicating that their spatial variability is high.(2)Through correlation analysis of mineral elements,soil nutrients and soil pH in tea and soil,it was found that manganese,chromium,calcium and other elements have significant correlation.There is a significant positive correlation between N,P,K and organic matter,and soil pH is significantly negatively correlated with available nitrogen,available phosphorus and available potassium.There was a significant negative correlation between Pb and Ca in tea and N,P and K,and there was a significant negative correlation between A1 and Na in soil and total nitrogen and total phosphorus in soil.There was a significant positive correlation between zinc and potassium in soil and total nitrogen in soil.Magnesium in soil was negatively correlated with total nitrogen,available nitrogen and total phosphorus,and positively correlated with total potassium.Soil total potassium had a significant positive correlation with soil zinc,manganese,lead,magnesium and aluminum,and the correlation coefficients were all greater than 0.3.The correlation between available potassium and mineral elements is also significant.(3)The spatial correlation of soil organic matter content is weak,while the spatial correlation between available nitrogen and available phosphorus is strong.The spatial correlation between soil chromium content and tea sodium content is weak.The spatial distribution of nutrients and mineral elements in the tea garden in different regions of Lishui region was different.The content of total nitrogen,total phosphorus and organic matter in the northwest showed an upward trend.The content of available nitrogen,available phosphorus and available potassium was low in the north and high in the middle south,and the pH of soil showed the opposite trend.The contents of selenium in tea and soil are higher.The contents of Cr,A1 and Pb in tea decreased gradually from north to south,while K and Mg were lower in the north.The contents of Zn and Cu in soil are relatively high in central Lishui.(4)Cluster analysis was used to distinguish tea from northern and central southern Lishui.Two principal components are identified by principal component analysis.Using manganese and aluminum as the dependent variable,three multivariate linear regression equations were established by stepwise regression using manganese,aluminum,nickel and potassium content and soil pH value.The fitting effect was good.The linear equation could be used as the characteristic equation of the mineral elements of tea and soil in Lishui area,and provided the basis for tracing the origin of tea origin.