New York Science Journal 2014;7(2) http://www.sciencepub.net/newyork 27 Impacts Of Land Uses Changes on Soil Fertility, Carbon and Nitrogen Stock under Smallholder Farmers in Central Highlands of Ethiopia: Implication for Sustainable Agricultural Landscape Management Around Butajira Area Getahun Haile, Mulugeta Lemenhi, Fisseha Itanna and Feyera Senbeta, Corresponding author: Getahun Haile, Email address: getahun_h@yahoo.com , tele 0912057770 Getahun Haile Email address: getahun_h@yahoo.com , Dilla University, Ethiopia Mulugeta Lemenhi, Email: elerhoi@yahoo.com , Farm African, Ethiopia Fisseha Itanna, email: fissehai@yahoo.com , Addis Ababa University, Ethiopia Feyera Senbeta, email: feyeras@yahoo.com , Addis Ababa University, Ethiopia Abstract: Landuses/land cover changes from natural forests to farmland, open grazing and eucalyptus woodlots, and subsequent changes in soil physical and chemical properties are widespread in Highlands of Ethiopia. Thus, assessing land use-induced changes in soil properties are essential for addressing the issues of agricultural landscape sustainability . The aim of this study was to examine the impacts of land use/land cover changes on soil properties, SOC and TN stock around Butajira area, Southern Ethiopia. The types of land uses considered on this study were: enset, cereal farms, grazing land, and Eucalyptus camaldulensis woodlots. Seven households having all the above mentioned land uses adjacent to each other were selected. For the purpose of this study, the selected household and land use types were considered as replication and treatments, respectively. 28 soil pits were dug i.e. one soil pit was dug at each land uses hence a total of eighty four soil samples were collected at three depths, namely 0-15cm, 15-30cm, and 30-45cm for chemical analysis. In addition, similar undisturbed soil samples were collected from same pits but opposite sides for soil bulk density and moisture content determination. Standard soil analytical procedures were followed in carrying out soil analysis. The results of the present study showed that land use changes induced significant differences on soil properties as reflected by the changes in bulk density, MC, pH, OC, TN , available P , OC and TN stocks. Soil bulk density was significantly higher in the cereal farms as compared to enset farms reflecting compaction of soil due to intensive tillage in cereal farms. Soil MC was significantly lowest under Eucalyptus woodlots compared to enset. Moreover, soil pH was lowest in woodlots and cereal lands as compared to other land uses. Soil under enset farms had higher OC, TN, available P, carbon and nitrogen stock as compared to other land uses. OC and total N stocks were shown a trend of enset farm > eucalyptus woodlots > grazing land > cereal land within 0-45 cm. Lowest OC and TN under cereal land showed the severity of land degradation under this land use utilization, where as the higher soil nutrients, OC and TN under enset soils suggesting the importance of this land use utilization for addressing soil nutrient and carbon depletion. Besides, woodlots and grazing land had higher OC, TN, SOC and TN stock as compared to cereal lands. Therefore, future restoration of soil should focus on strategies that improving the soil nutrient and carbon storage under cereal land for enhancing sustainable agricultural landscape management, thereby improving the livelihood of agrarian community. However, fast growing nature of eucalyptus species may negatively affects soil reaction and moisture . Planting eucalyptus also negatively affects the crop yield of adjacent farm lands due to root competition and shading effects. Thus, current strategies of planting fast growing eucalyptus woodlots in response to scarcity of forest products and economic benefits, should be considered the negative impacts on soil and crop yields of neighboring farmlands . Hence, there is a need to develop proper land use policy and sustainable soil management and cropping practices to combat the on ongoing soil degradation in the study area. [Getahun Haile, Mulugeta Lemenhi, Fisseha Itanna and Feyera Senbeta. Impacts Of Land Uses Changes on Soil Fertility, Carbon and Nitrogen Stock under Smallholder Farmers in Central Highlands of Ethiopia: Implication for Sustainable Agricultural Landscape Management Around Butajira Area. N Y Sci J 2014;7(2):27-44]. (ISSN: 1554-0200). http://www.sciencepub.net/newyork . 4 Key words：Land use, soil physical and chemical properties, soil degradation, Ethiopia 1. Introduction Soil degradation in the form of plant nutrient depletion is the major environmental problems in the highlands of Ethiopia. Among Sub-Saharan countries, Ethiopia is the most seriously affected country by land degradation [World Bank, 1998]. Previous studies have shown negative nutrient balance mainly C, N and P indicating that soil is already mined [Stoorvogel and Smaling, 1990]. The overwhelming land degradation in Ethiopia have been caused due to land use changes, including deforestation, over grazing, and improper cultivation of agricultural land which led to accelerated soil erosion and associate soil nutrient deterioration [FAO, 1986; Hurni, 1988]. Furthermore, widespread