The Soil and Water Assessment Tool (SWAT) uses the popular Curve Number (CN) method to determine the respective amounts of infiltration and surface runoff. While appropriate for engineering design in temperate climates, the CN is less than ideal in monsoonal climates and areas dominated by variable source area hydrology. The CN methodology is based on the assumption that there is a unique relationship between the average moisture content and the CN for all hydrologic response units, a questionable

In the Highlands of Ethiopia, soil erosion is a pressing challenge causing deterioration of soil quality including soil fertility. To overcome this problem, the government has been taking various sustainable land management (SLM) measures. This study was conducted in 2011 to investigate the long-term impacts of soil conservation on soil qualities and crop performance at Anjeni watershed in the central highlands of Ethiopia. Soil and crop samples were collected from the lower (deposition), middle and upper (loss) zones of the terraces at a depth of 30cm.The test crops were maize (Zea mays) and bread wheat (Triticum aestivum). Soil samples were also taken at toe slope, foot slope, back slope, shoulder slope and crest positions of the watershed from 0-30 cm soil depth to evaluate the status of soil qualities along the catena. Results of the study showed that soil pH, exchangeable cations, available phosphorus, sum of exchangeable bases and percent base saturation showed non-significant difference between the loss zone and deposition zones, whereas higher mean value of organic carbon, and total nitrogen were obtained at the deposition zone than the loss zone. For both testing crops, higher mean yields were found at deposition zones followed by the middle zones while the lowest value was obtained from the loss zones. Soil pH, exchangeable cations, available phosphorus, sum of exchangeable bases, percent base saturation, organic carbon and total nitrogen showed significant variation due to slope position differences. Toe slope position followed by crest slope position showed higher mean value of the parameters. The shoulder slope position had the lowest mean value for all parameters. From the results of the study, it was possible to conclude that soil conservation measures implemented at Anjeni watershed reduced soils erosion, improved soil qualities and increased crop yield. It is, therefore, possible to recommend the need for scaling up of results obtained from learning watersheds on soil conservation activities to the highlands of Ethiopia to improve the soil quality and livelihoods' of the society.

Background: Land degradation is one of the major threats to food security and natural resources conservation Zikre watershed. The objective of the study was to investigate the effects of land use types, management practices and slope classes on soil physico-chemical properties.

Background: To identify and quantify the impact of climate change on socio-economic sectors and ecosystems, many global studies have been carried out and policy changes for mitigation and adaptation were recommended. However, the old-fashioned top-down approach, global study, has little local and regional specificity and has failed to address the regional and local consequences of climate change. Thus, this research was conducted in filling such knowledge gaps in Lake Tana sub-basin. The research was aimed at addressing the national and local issues of climate change and was done by analyzing time series temperature and rainfall trends in the highlands of Ethiopia and LTSB in particular. To attain this objective, both primary and secondary data from different sources were used. The collected data were analyzed following quantitative and qualitative analysis methods and Manna Kendall Trend test method was used. Results:The main findings revealed that the mean, maximum and minimum temperature had a general increasing trend; whereas, rainfall amount showed a general decreasing trend in Lake Tana Sub-basin. Analysis of the 40 years annual total rainfall data from 109 representative ground based meteorological stations in Ethiopia indicated a coefficient of variation ranging from 20 to 89 %. Of the 109 stations considered, 17 had above 42 % coefficient of variation highlighting the extreme variability of rainfall over the country Conclusions:To conclude, development planners should design strategies and plans by taking into account a declining summer rainfall and increasing temperature impacts on rural livelihoods.

Information about effects of different land use systems on soil physico-chemical properties is crucial for best land management practices. This study was, therefore, conducted to evaluate the same on Nitosols of Achefer District, Northwestern Ethiopia. The landuse systems studied included grassland, cultivated land, plantation forest and natural forest. The research was superimposed on land use systems that were located nearby on similar soil, contour line and slope classes. Undisturbed core and disturbed composite soil samples were collected randomly from two sites with three replications for each landuse system at two varying depths (0-15 cm and 15-30 cm). The undisturbed soil samples were analysed for bulk density, particle density, porosity and moisture content at different pressures; while the composite soil samples were analyzed for pH, organic carbon, total N and available P. Results of the study indicated that the lowest bulk and particle densities, the highest total porosity, and higher moisture content at both field capacity and permanent wilting percentage were found under natural forest land use system. In contrast, the highest bulk and particle densities, the lowest total porosity and lower water contents at both field capacity and permanent wilting percentage were obtained under the cultivated landuse system. Soil pH was moderately acidic under all landuse systems. The lowest organic carbon, total N, and C:N ratio were recorded under cultivated land; whereas the highest values of the same parameters were found under natural forest. In all landuse systems, organic carbon and total N decreased with soil depth. The highest and lowest available P contents were recorded under natural forest and grassland, respectively. From the results of the study it was possible to conclude that conversion of forest lands to cultivated and grasslands had detrimental effects on the soil physico-chemical properties under subsistance farming systems of the study area. It is, therefore, recommended that appropriate and integrated land management options for different land use syetems are required to sustain agricultural productivity while protecting the environment.