Impact of organic materials (tea waste and farm manure) on yield, protein content, fiber fractions, and mineral composition of tea plants in an organic system

Abstract

This study aimed to investigate the effects of organic materials and fertilizers on tea plant yield and quality in an organic tea garden in Türkiye. The objective was to identify sustainable alternatives to synthetic fertilizers that could enhance tea production while maintaining or improving nutritional quality. A two-year field study (2019–2020) was conducted in an organic tea garden in Pazar, Rize, Türkiye, to assess the impacts of various organic materials on tea plant yield and quality. A Randomized Complete Block Design with split-split plots was employed, with three organic materials (Control, Farm Manure, Tea Waste) as main plots, five organic fertilizers (Control, Organoferm, Neobioplus, Bionur, Orbitosol) as subplots, and three harvest times as sub-sub plots. The study analyzed fresh and dry yield, protein content, cell wall components (Acid Detergent Fiber [ADF] and Neutral Detergent Fiber [NDF] representing indigestible fiber fractions, and Acid Digestible Protein [ADP] indicating protein availability), and macroelements (Phosphorus [P], Potassium [K], Calcium [Ca], and Magnesium [Mg]). Tea waste significantly enhanced protein content, yield, and phosphorus levels, while farm manure increased fresh and dry yields, as well as potassium and magnesium concentrations. Organoferm fertilizer improved most quality parameters except for calcium and magnesium. Results indicated that organic amendments, particularly farm manure, tea waste and Organoferm fertilizer, can be effective in improving tea plant yield and nutritional quality, offering a sustainable alternative to synthetic fertilizers.