In order to accommodate the disclosure of production history, the Kagoshima Prefecture Tea Market has developed the "Chapion Net" system, which uses the cloud to manage various fertilization and cultivation management data in producers' fields, production records, unit prices, and quality information obtained through image analysis of crude tea.
In order to establish a way to utilize the production history data accumulated in this system in the field, 11 tea producers in the area set up model tea farms and collected 35 items of data over a five-year period, including the number of first-flush tea buds, crude tea components, and soil analysis values, in addition to the production history data from "Chapion Net." From this data, they were able to determine the fertilization and cultivation management that affects the "gross income" (= unit price x yield) of first-flush tea. The search was carried out using the functions of JMP.
Bivariate and multivariate correlations and PLS regression showed that the number of buds and the date of harvesting of the first flush of tea affected gross income. Principal component analysis of the crude tea components showed that the number of days covered had a large effect on the total nitrogen content. Additionally, outlier analysis of the principal component analysis of soil analysis values revealed fields where the component values were significantly different from other soils and in need of soil improvement.
The above results clarified the key points of the annual cultivation system for ensuring gross income, such as fertilizer management and indicators for ensuring crude tea quality and soil quality. In the future, we will use this information to provide guidance on fertilizer management in the field.
