ALBERT

Description: Different land use systems can have different soil properties. It is important to study the soil properties for wise use and sustainable management of land resources. This article reports the findings of a research conducted in Makwanpur district of Nepal, to determine and compare the selected physicochemical and hydrological properties of soil in forest, rainfed agriculture land, and grassland. These forest, agriculture land, and grassland represent tropical land use systems. Soil samples were collected from 0 to 30 cm depths of soil profile from nine randomly distributed pits dug in forest, grassland, and rainfed agriculture land in 2019. Soil samples were analyzed in the laboratory to determine the soil properties using standard methods. Bulk density, porosity, moisture content and infiltration, pH, total nitrogen, available potassium, and available phosphorus were quantified from the soils samples. It was found that the highest BD was found in the grassland (1.29 g/cm³) followed by the forest (1.23 g/cm³) and rainfed agriculture land (1.18 g/cm³). The highest porosity was found in rainfed agriculture land (55.50%) followed by the forest (53.74%) and grassland (51.63%). The highest MC was found in the grassland (26.94%) followed by the forest (10.17%) and rainfed agriculture land (9.92%). The mean cumulative infiltration amount was highest in the rainfed agriculture land (39.27 cm) followed by the forest (33.47 cm) and grassland (8.4 cm). The highest soil pH was found in the grassland (7.91) and the lowest pH (5.70) in the forest. The highest level of total nitrogen was found in rainfed agriculture land (0.121%), followed by the forest (0.106%) and grassland (0.096%). The highest level of available phosphorous was found in rainfed agriculture land (84.94 ppm), followed by the forest (67.76 ppm) and grassland (6.69). The highest level of available potassium was found in rainfed agriculture land (154.24 ppm), followed by the forest (84.49 ppm) and the grassland (44.71 ppm). Bulk density, porosity, and total nitrogen were not found to be significantly different and other soil properties were found to be significantly different between different land use systems. The contribution of farmers in maintaining soil properties on the farmlands is clearly reflected in the results, so their knowledge on soil management needs to be explored and adapted for wise use and sustainable management of other land use systems.

Description: This paper reports the findings of a research conducted in Kankali community forest, Chitwan, Nepal, to quantify the vertical distribution of soil organic carbon (SOC) and nitrogen in 1 m soil profile depth. This community forest represents a tropical Shorea robusta-dominated community forest. It was found that the soil had 122.36 t/ha SOC and 12.74 t/ha nitrogen in 1 m soil profile in 2012, with 0.99% soil organic matter and 0.10% nitrogen concentration in average. Carbon and nitrogen ratio (C/N ratio) of the soil was found to be 9.90. Both bulk density and C/N ratio were found increasing with increase in soil depth. The SOC and nitrogen were found significantly different across different soil layers up to 1 m soil profile depth. The average pH of the forest soil was found to be 5.3. Looking into the values of stocks of SOC and nitrogen, it is concluded that Kankali community forest has played a role in global climate change mitigation by storing considerable amounts of SOC. Involvement of local community in management of tropical forest cannot be overlooked in the process of climate change mitigation.