Temporal Variation in Soil Nutrient Availability in Forest Ecosystems of Telangana State, India

Abstract

Forest ecosystems play an important role in maintaining soil fertility through continuous organic matter inputs and nutrient cycling. The present study was conducted to assess temporal changes in soil nutrient availability across five forest locations in Telangana State between May 2023 and April 2024. The mean available nitrogen content increased from 266 to 295 kg ha⁻¹ between May 2023 and April 2024. Available phosphorus increased from 46.8 to 50.1 kg ha⁻¹, while potassium increased from 413 to 425 kg ha⁻¹. The highest concentrations of available N, P, and K were recorded at Adilabad during both sampling periods. The mean concentrations of Fe and Cu increased from 3.93 to 4.00 and 2.60 to 2.71 mg kg⁻¹, respectively. Similarly, Mn, Zn, and B increased from 7.65 to 7.88, 1.49 to 1.58, and 0.52 to 0.55 mg kg⁻¹, respectively. The mean molybdenum concentration increased from 0.41 to 0.44 mg kg⁻¹ during the study period. Humic acid content increased from 1.75 to 1.78 g kg⁻¹, while fulvic acid increased from 1.22 to 1.24 g kg⁻¹. Adilabad generally recorded higher concentrations of available nutrients and humic substances, whereas Mudimyal showed comparatively lower values for several nutrients. The observed increases may be associated with continuous deposition and decomposition of leaf litter and other organic residues. Continuous organic matter inputs within forest ecosystems may contribute to maintaining soil fertility and nutrient availability.