International Journal of Environment

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2022-06-16T06:15:10+00:00

Study of the habitat, and potential distribution of Himalayan Ginseng (Panax pseudoginseng Wall.), and the diversity of its associated species in Nangkor and Shingkhar Geogs, Zhemgang, Bhutan

2022-06-16T05:20:02+00:00

Panax pseudoginseng Wall. is a highly sought-after medicinal plant in Bhutan, but little is known about its distribution and habitat in the country. Therefore, this study aimed to determine suitable habitat, and potential distribution of P. pseudoginseng, and the diversity of its associated species in Nangkor and Shingkhar Geogs, Zhemgang, Bhutan. A total of 42 plots were laid using a purposive sampling method. Various parameters like slope, aspect, soil nutrients, soil pH, humidity, temperature, and soil water tension were collected. The Spearman’s correlation test indicated that the temperature and canopy cover had negative association with the counts of P. pseudoginseng. The Spearman's correlation test for NPK indicated that Phosphorus had significant difference with the counts of P. pseudoginseng. A total of 1,277 species distributed in 87 genera of 66 families were recorded including the trees, herbs and pteridophytes. Fagaceae was the most dominant family in the study area. Seven types of forest were classified based on the floristic composition of trees. Potential distribution was obtained using ArcGIS that combined observation data, reclassification and Weighted Overlay. Overall, 95.39% of an area under Zhemgang District is suitable for the growth of P. pseudoginseng.

Influence of land-use systems on hydraulic properties of soils in Yenagoa and Amassoma, Bayelsa State, Nigeria

2022-06-16T05:35:08+00:00

This research aimed to determine the effect of different land-use systems on the matric potential, and hydraulic conductivity of the soils of Yenagoa and Amassoma communities. Soil samples were collected from four respective land-use types namely: Fallow land, Oil Palm Plantation, Plantain Plantation, and Virgin land. A total of 12 samples were bulked from three replicates at each land use type and were collected at depths of 0-15cm, 15-30cm, and 30-45cm respectively. The samples were taken to the laboratory to analyze their physical, chemical, and hydrological properties. The result showed that the different land use had a significant effect (P<0.05) on some soil physical, chemical, and hydraulic characteristics. The different land-use systems had a significant effect on the soil hydraulic conductivity with the highest in virgin (13.6 cm/hr) and lowest in the plantain plantation (7.6 cm/hr). The virgin land recorded the highest Soil Water Holding Capacity (SWHC) of 2.85 cm with a range of 1.55 – 2.85cm and Plant Available Water Capacity (PAWC) of 0.19 cm³cm^-3, with a range of 0.10 - 0.19 cm³cm^-3, while the plantain plantation recorded the lowest (1.55 cm and 0.10 cm³cm³). Based on the study, it is recommended that soils with high Plant Available Water Capacity (PAWC) and Soil Water Holding Capacity (SWHC) be used to cultivate crops that are non-tolerant to water stress while organic amendments are used on soils with low fertility.

Nutrient dynamics under unmanaged rubber, cocoa, and oil palm plantations in a sandy soil under humid lowland tropical climatic conditions

2022-06-16T05:56:30+00:00

Changes in land use are an important issue in many farms that affect soil biological, chemical, and physical properties temporarily under cropping cycles or when the land is permanently allocated to perennial tree crops, e.g., in agroforestry. This study investigated the changes in sandy soil chemistry induced by three perennial tree crops (rubber, cocoa, and oil palm) growing in 30-year-old unmanaged and abandoned plantations and the surrounding grasslands dominated by cogon grass. A disruptive approach was used to collect soil samples from the top 60 cm under all the tree crops and in the grassland soils. A 500-gram sample of each soil originating from under each tree crop and the grassland were carefully packed into pre-labeled paper bags in triplicate (n=3) and sent to the laboratory for analysis of a selected number of primary and secondary macronutrients, micronutrients, and other soil parameters. The results showed N, K, Mg, Cu, Zn, and S were generally deficient in the sandy soil. A tree crop-specific soil organic matter, organic carbon, carbon stock contents, and water holding capacity measured were high under rubber and cocoa only. The variation in pH, electrical conductivity, bulk density, total porosity, and particle composition were generally similar except that the sand composition was lower in the soils under rubber and oil palm.

Performance of rooftop rainwater harvesting system as a source of drinking water

2022-06-16T06:03:23+00:00

Rainwater Harvesting Systems (RWHSs) are increasingly being used as an alternative or supplementary source of water to curb the water supply deficit in the Kathmandu valley. The harvested rainwater is primarily used for non-potable purposes like flushing toilets and irrigation, but the knowledge on the use of rainwater for potable purpose is remarkably sparse. This study assesses the suitability of rainwater in terms of quantity and quality in a public school that adopts Rooftop RWHS as the source of drinking water. In this study, we observed that the volume of rainwater being harvested is sufficient to address the current demand of drinking water, with a mean rainfall of 1664 mm on a catchment area of 372 m². Storage capacity needs to be expanded if the demand increases. Physico-chemical and microbial analyses of water samples (before and after a series of treatments) were carried out for the winter, monsoon, and post-monsoon seasons. The values of physico-chemical parameters of the water samples, in all the seasons, were well within both the National Drinking Water Quality Standards (NDWQS, 2005) and the World Health Organisation (WHO, 2017) guidelines for drinking water, while fecal coliforms were detected in the storage tank, but were absent in tap water after the treatments. Based on the findings, we suggest that the harvested rainwater could be used for drinking purposes if properly treated. RWHS use at the institutional level, like in schools, on the one hand, curbs the increasing demand for water in water-deficit locations like Kathmandu, and on the other, encourages the adoption of such sustainable technologies for the water supply.