Soil Loss and Its Impact on Crop Productivity Under Varying Land Uses in Demba-Gofa District, Southern Ethiopia

Abstract

Soil erosion is the main cause of land degradation in Ethiopia and annually several tons of soil is removed away from the highlands. Thus, the purpose of this study is assessing soil erosion rates under various land uses and identifying the main contributing factors in Demba-Gofa woreda. A multistage random sampling approach was used to identify the research subjects. Questionnaire, key informant interview, FGDs, and field observations were used as data collection instruments to identify the major contributing factors of soil erosion in the studied woredas. Finally, the application of RUSLE model predicted that the lowest annual rate of soil loss observed at forest land is approximately 5.43 t ha-1 year, -1 whereas the highest amount of soil loss in crop land was about 36.01 t ha-1 year-1 and followed by in the grass land 22.10 t ha-1 year-1 and in the shrub land 11.29 t ha-1 year-1. The analysis of multiple linear regression model predicted that deforestation activities, educational level of farm household heads, mismanagement of cultivated lands, perception of local farmers on soil erosion, land size, farm distance, and slope of the land were found to significantly aggravates soil erosions at p < 0.05 level. Land sat satellite image with Arc-GIS 10.3 analysis for the last 15 years (2000-2017) of the three rural kebeles indicated that a total of 489.4 ha (56.3%) forest land was converted into shrub and grasslands. Thus, the national and the local governments should focus on reforestation, awareness creation on soil erosion and how farmers manage farmlands.
Keywords: Soil erosion, natural resource degradation, RUSLE, Demba-Gofa