Long Term Effects of Integrated Management Practices on Soil Chemical and Biological Properties in Tea Cultivation

Abstract This study evaluated the long-term effects of integrated soil rehabilitation practices on soil chemical, biological, and productivity indicators in strongly acidic tea plantations in Türkiye. The objective of this study was to evaluate the effectiveness of the integrated TEMA model (15 t ha⁻¹ tea-waste compost + 2 t ha⁻¹ dolomite + hoeing) in restoring degraded soils compared to single-input conventional or organic management practices. Between 2018 and 2022, two tea gardens, one conventionally fertilized and one organically managed, were monitored under field conditions. The TEMA treatment was compared with chemical fertilization and farmyard manure-only systems. Fresh tea yield was recorded each year. Soil samples from 0 to 10 and 10–20 cm were analyzed for pH, EC, CaCO₃, soil organic matter, qCO₂, fungal to bacterial ratio, β-glucosidase, and catalase. Principal component analysis was used to evaluate relationships. Yield declined under chemical fertilization (17650–15200 kg ha⁻¹), whereas TEMA maintained stable yields (20100–20130 kg ha⁻¹). In the organic system, manure-only plots produced 6600–8800 kg ha⁻¹, while TEMA increased yields from 27,500 to 35,400 kg ha⁻¹. Soil pH increased to 5.6–5.7 under TEMA, with soil organic matter reaching 3.79% and higher enzyme activities. Principal component analysis identified soil organic matter, pH, CaCO₃, and enzyme activities as the main drivers of system differentiation. Integrated soil management improved strongly acidic tea soils through coordinated chemical buffering and biological functioning. The TEMA model provides a practical approach for sustainable soil rehabilitation and long-term productivity.