Soil-plant transfer of Mn, Mo, and Zn and tea quality response to microelement fertilization in yellow-gleyic pseudopodzolic soils of Lankaran, Azerbaijan.

Yellow-gleyic pseudopodzolic soils of Lankaran, Azerbaijan, are an understudied soil type with poorly characterized microelement dynamics. This study investigated the distribution, mobility, and biological absorption coefficients (BAC) of manganese (Mn), molybdenum (Mo), and zinc (Zn) under Camellia sinensis cultivation and evaluated fertilization effects on leaf yield and quality. Field experiments ran over three growing seasons (2022-2024) on a 1.7 ha plantation with seven treatments and three replicates against an N150P150K90 background. Mo showed the highest soil mobility across depths (45.5-83.3%), compared with Zn (< 10%) and Mn (< 5%) under acidic, periodically gleyed conditions. Tea-leaf BAC followed Mo > Zn > Mn (4.32, 2.37, and 0.30), inverse to absolute tissue concentrations. One-way analysis of variance showed significant treatment effects on plant height (F = 22.5, p < 0.001) and bush diameter (F = 44.5, p < 0.001), with Mo2 highest. Friedman tests across seven treatment-level observations indicated harvest-period differences (p < 0.01); Holm-adjusted exact paired comparisons placed July above May and September for all three quality indicators, with small n limiting p-value resolution. Mo2 had the highest observed July quality values (tannin 24.94%, caffeine 2.99%, extractive substances 47.80%) and the highest three-season mean yield (16.69 t/ha, + 12.1% over control). Treatment-level quality and yield comparisons remained descriptive because replicate-level variance was unavailable. These single-site findings support further evaluation of Mo-responsive microfertilization in this soil system.