Impact of land use systems on soil chemical properties in Kodagu, Karnataka

Abstract

Land use systems significantly influence soil properties, making it essential to understand their impacts for effective land management. This study aimed to assess the effects of different land use systems on soil chemical properties in Kodagu district, Karnataka, by analyzing five distinct land use types: Natural Forest (T1), Coffee-based Agroforestry (T2), Teak Plantation (T3), Agricultural Land (T4), and Fallow Land (T5). A randomized complete block design with five treatments and four replications was used, and soil samples were collected at three depths: 0-15 cm (d1), 15-30 cm (d2), and 30-45 cm (d3). The results revealed significant differences in soil chemical properties across the land use systems, with Natural Forest (T1) recording the highest mean values of available nitrogen (443.98 mg/kg) and soil organic carbon (SOC) (3.72%), followed by Coffee-based Agroforestry (T2) and Teak Plantation (T3), while the lowest values were observed in Fallow Land (T5) and Agricultural Land (T4). Similarly, Coffee-based Agroforestry (T2) showed the highest available phosphorus (47.54 mg/kg) and potassium (331.13 mg/kg), followed by Natural Forest (T1) and Teak Plantation (T3), with the lowest values recorded in Fallow Land (T5) and Agricultural Land (T4). Soil pH and electrical conductivity (EC) were highest in Fallow Land (T5) and lowest in Natural Forest (T1), and all chemical parameters, except soil pH, showed a decreasing trend with increasing soil depth. The findings indicate that Agricultural and Fallow Lands exhibited poorer soil chemical properties compared to other land use systems, emphasizing the impact of land use changes on soil fertility.