Soil degradation can be described as deterioration of the physical, chemical and biological or economic properties of soil (Maitima and Olson, 2001). It is a principal environmental problem in Ethiopia which is manifested mainly in the form of soil erosion, soil fertility loss, and crop yield reduction. The excessive dependence of the Ethiopian rural population on natural resources, particularly land, as a means of livelihood is an underlying cause for land and other natural resources degradation (EPA, 1998). Soil degradation is caused and aggravated by erratic and erosive rain fall, topographical setup and inappropriate land use practices (Tamene et al. 2006; Ciampalini et al. 2008; Nyssen et al. 2009; Tesfaye and Fanuel, 2019).
Generally, water erosion is prominent in highlands of Ethiopia where erratic rainfall generate erosive runoff (Hurni, 1993). Various studies provided empirical evidence of the severity of the problem. For example, the Ethiopian highland reclamation study (EHRS) estimated 1.9 billion tons annual topsoil loss from the highlands due to water erosion, which is equivalent to 8 mm soil depth or 130 t ha− 1 annual losses (FAO, 1986). Hurni (1993) also reported as much as 300 t ha-1 annual soil loss from croplands with average rates of 42 t ha− 1. The extent of soil loss due to erosion in the Ethiopian highland is high varying between 42 t ha− 1 y− 1 and 175.5 t ha− 1 y− 1 (Admasu et al., 2017).
The impact of soil erosion is complex leading to reduction in soil depth and moisture storage capacity together with soil-nutrient losses, and ultimately results in reduced agricultural production and productivity (Vancampenhout et al., 2006; Tesfaye and Fanuel, 2019). Soil erosion is a threat not only to agriculture but also to the economy, as the country´s economy depends on agriculture.
Soil conservation is the only known way to protect the productivity of the land (Panda, 2007). Different SWC Measures are in place to mitigate land degradation problems. Their performance considerably varies based on type of structure, age of structure, land scape position (Tesfaye and Fanuel, 2019). Space occupied by soil and water conservation (SWC)structures, impediment to traditional farming activity, water logging problems, weed and rodent problems, huge maintenance requirement, are some of the reasons that cause farmers refrain from SWC works(Mitiku.et al., 2006).
Thus, this study aimed to examine the impact of SWC (Stone Bund) on selected soil physical and chemical properties as compared to non-conserved (Control) farm plots in Masha-Deniba Micro Water Shed in Zima Waruma kebele of Loma woreda.
The specific objectives include:
- To investigate the impacts of stone bunds and their age on soil physical and chemical properties;
- To investigate the effects of landscape positions on soil physical and chemical properties of the watershed.
- What impacts were observed on soil physical and chemical properties by the application of SWC technologies?
- Is age of stone bund affect the soil fertility status?
- Are there differences in soil properties among topographic positions?