Dynamics of Soil Nutrients under the Agroforestry Ecosystem in Telangana State, India

Abstract

Agroforestry systems play an important role in maintaining soil fertility through continuous organic matter inputs and nutrient recycling. The present study was conducted to assess changes in soil nutrient availability in selected agroforestry ecosystems of Telangana State between May 2023 and April 2024. Five agroforestry locations comprising teak (Tectona grandis L. f.) + citrus, teak + mango, and teak + guava systems were evaluated. Soil samples collected from 0–30 cm depth were analysed for available macronutrients (N, P and K), micronutrients (Fe, Cu, Mn, Zn, B and Mo), and humic and fulvic acids using standard analytical procedures. Differences between the two sampling periods were assessed using a paired t-test. The mean available N, P and K contents increased significantly from 241, 34.3 and 363 kg ha⁻¹, respectively, in May 2023 to 273, 36.7 and 375 kg ha⁻¹ in April 2024. Similarly, the mean concentrations of Fe, Cu, Mn, Zn, B and Mo increased from 3.58, 2.37, 7.34, 1.31, 0.45 and 0.32 mg kg⁻¹ to 3.67, 2.46, 7.54, 1.44, 0.50 and 0.35 mg kg⁻¹, respectively. Humic acid content increased from 1.31 to 1.34 g kg⁻¹, while fulvic acid increased from 0.96 to 0.99 g kg⁻¹ during the study period. Kandlapalli consistently recorded the highest concentrations of most nutrients and humic substances, whereas Rajendranagar generally recorded the lowest micronutrient concentrations. The observed increases in nutrient availability and humic substances may be associated with continuous organic residue inputs, leaf litter decomposition, microbial activity, and nutrient recycling within the agroforestry systems. The findings indicate that sustained organic matter inputs under agroforestry systems can contribute to improved soil nutrient availability and the accumulation of humified organic matter over time.