Multi-Element Absorption, Enrichment and Translocation of Tea Trees in Different Rock Zones of Wuyishan and Their Effects on Tea Quality

Wuyi rock tea quality in different rock zones differs significantly, and it is of great significance for the development of the rock tea industry to deeply reveal the mineral nutritional basis of its quality formation. In this study, the rhizosphere soils, root systems and leaves of tea trees from 180 tea plantations in different rock zones were collected, to explore the migration pattern of elements in the “soil and root system-leaf” of tea trees in different rock zones. The results showed that the contents of tea polyphenols, theanine, and caffeine were significantly higher in the authentic zone than in the semi-rock zone and the continent zone, with all three quality indices exhibiting a consistent decreasing trend from ZY to BY to ZC, and their mean values in ZY were approximately 1.2-fold and 1.4-fold higher than those in BY and ZC, respectively. The ability of the root system of tea trees in different rock zones to enrich Mn, P and S, their translocation from roots to leaves, and their accumulation in leaves directly affected tea quality. Using four machine learning approaches based on enrichment coefficients of key elements, the classification accuracy for the three rock zones reached 100%. The above conclusions were further verified by hydroponic experiments with Mn, P or S treatments, which confirmed that P exerted the strongest influence on tea quality, followed by S, with Mn showing the smallest effect. This study reveals the mineral nutrient basis for the formation of rock tea quality and lays an important theoretical foundation for the elemental directed regulation of Wuyi rock tea quality.