|Volume 23, No 3
|2023 July - September
This study presents Russula purpureoverrucosa marking the first record of its presence in India. Additionally, we have identified other fourteen species from the family Russulaceae and their taxonomic descriptions were given. This study was constrained to a small area, however, it hints at the potential for the discovery of more Russulaceae in Mizoram. The findings suggest that the region may host a rich diversity of these fungi, and further research in broader areas could unveil additional Russulaceae in Mizoram.
Jhum cultivation commonly known as shifting cultivation is the main form of agricultural practice in Mizoram. This gradually causes changes in the physico-chemical properties of soil. The study of soil organic carbon on current jhum and jhum fallows intends to find out the impact of jhum cultivation on soil organic carbon in relation to the period of jhum fallows. Soil samples were collected in triplicates from four different sites seasonally i.e. thrice in a year. The study was conducted within Rawpuichhip, Mamit i.e., Current Jhum, J and Jhum Fallows (which is categorized into two sites; Short fallow, SF - 2 to 5 years and Long fallow, LF - more than 8 years) and undisturbed area (adjacent forest) during the year 2022. Soil samples were collected in triplicates from three different depths 0-10 cm, 10-20cm, and 20-30cm with the help of a soil corer. It was found from the study that Soil Organic Carbon (SOC) value ranges from 1.21±0.17 % - 2.38±0.10 %. The results indicate that among the study area, short fallow has the least amount of SOC while current Jhum and the undisturbed area tend to have higher concentrations of SOC
The traits of residual soils are dependent upon the environmental factors of climate, parent materials, topography and drainage, and time. The structures and designs of buildings are greatly affected by the properties of soils; such as plasticity, compressibility, or strength. A proper foundation soil is needed for the stability of engineering structures like dams, buildings, bridges, tunnels, towers, etc. one that is built into or on top of the soil. Changsari is situated on the north bank of the Brahmaputra River, Kamrup district of Assam. Based on the geotechnical investigations, the region comprises four different soil horizons; i.e. Horizon A, Upper Horizon B, Lower Horizon B and Horizon C, classified as Clay (or organic soil) with low plasticity, Silt with high plasticity, Silt with low plasticity, and Clay with low plasticity respectively. The cohesive strength (C) decreases with depth, and the grain sizes vary in each horizon. The results of the geotechnical investigations show that the geotechnical characteristics of the residual soils discovered in the three separate research areas follow a consistent pattern.