L.K. Thang Ngaihte, Elizabeth Nemhoihkim, O.P. Tripathi and B.P. Mishra
Abstract
This study investigated impact of altitudinal variations in soil physical and chemical properties of current jhum (shifting cultivation) fields in Churachandpur district, Manipur. Significant differences were observed across the altitudinal gradient, with higher elevations (>1000 m) exhibiting superior soil moisture content (up to 24.81%), water holding capacity (43.58%), organic carbon (3.53%), available nitrogen (616.75 kg/ha), and potassium (263.68 kg/ha) as compared to lower altitudes (<500 m). Conversely, bulk density decreased from 1.33 g/cm3 at middle altitudes to 0.94 g/cm3 at higher elevations. The favourable conditions at higher altitudes, such as cooler temperatures and higher moisture availability, likely reduced organic matter decomposition rates and nutrient losses through leaching and erosion, leading to organic matter accumulation and lower anthropogenic disturbances also contributed to preserving soil quality. At lower altitudes, soil quality was better than middle altitudes, possibly due to greater salt accumulation and presence of base-forming cations, resulting in higher pH and available phosphorus levels. In contrast, the midaltitude sites exhibited poorer soil fertility indicators, potentially influenced by anthropogenic activities like shifting cultivation practices, felling of trees, and erosion of soil nutrients. Overall, this study contributes to our understanding of the relationships between altitude, soil properties, and agricultural practices, particularly in the context of indigenous farming systems in the hilly regions of northeastern India. The findings have potential implications for optimizing land use, promoting sustainable agriculture, and safeguarding the ecological integrity of these fragile ecosystems.