Comprehensive Analysis Revealed the Specific Soil Properties and Foliar Elements Respond to the Quality Composition Levels of Tea (Camellia sinensis L.)

Abstract

C. sinensis cv. Sijichun is a representative Taiwanese low-altitude tea cultivar native to central Taiwan. To enrich the taste of tea in a geographically disadvantaged area, soil management became necessary but was obscure. The purpose of this study was to screen the main soil factors that influence the quality composition levels of tea to optimize the efficiency of tea tree horticulture. Soil and tea leaf samples collected from 20 tea plantations determined thirteen soil properties, nine leaf element nutrients and aluminum, and five main extractable quality compositions, including polyphenols, catechins, flavones, free amino acids, and caffeine in tea infusion. Pearson’s correlation analysis and principal component correlation analysis showed that soil available nutrients cannot respond to the concentration of corresponding essential elements in tea leaves; nevertheless, adequate leaf macronutrients and Zn could enhance polyphenol, free amino acid, and caffeine contents, but decreased flavone contents, and showed their consistent effect by soil characteristics. Of note, soil pH, EC, exchangeable calcium, exchangeable magnesium, total concentration of manganese, and total concentration of copper were shown as significant impact factors on free amino acid content. In summary, regulating the pH of soil under 3.51–5.21 in our study and managing soil effective Ca, Mg, and Zn supply could help to obtain a greater umami taste of tea.