The Effects of ‘<i>Fanya juu’</i> Soil Conservation Structure on Selected Soil Physical & Chemical Properties: the Case of Goromti Watershed, Western Ethiopia

Abstract

Soil degradation is evident in the mountainous areas of Ethiopia, is often represented as results of human pressure. It can be improved through different Soil and Water Conservation (SWC) measures. The study was conducted in Goromti watershed, in western Ethiopia to evaluate the impact of Fanya juu structures on some soil physical & chemical properties. Cultivated fields treated by five years and ten years old fanyajuu structures were compared with non conserved cultivated land (control) and evaluated under three slope gradients. The slope gradients were; gentle (3-15%), moderately steep (15-30%) and steep slope (>30%). A total of 27 soil samples were collected from the top 20 cm soil depth replicated three times and selected physical and chemical properties were analysed in the laboratory. The results of the study showed that soil pH, soil organic carbon (SOC), total nitrogen (N) were significantly (p≤0.05) different on farms treated by the fanyajuu compared to the non-conserved plots as well as under the different slope gradients. Bulk density (Db), sand and clay fractions were significantly varied with slope gradient. Soil organic carbon and total N were higher while bulk density was lower in soil under the non-conserved fields than in fields with fanyajuu structures. But no significant difference was observed in soil bulk density, sand and clay fractions among treatments. Similarly, CEC, available K and available P, and exchangeable K + , Ca 2+ , and Mg 2+ didn't show any significant differences with respect to structures and slope gradient. The research indicates that structures could benefit farmers through improving the nutrient status better if integrated with agronomic measures by using vegetation suitable for the local environment in one hand, and properly maintained for longer period of time, on the other.

Assessing the potential of biochar and charcoal to improve soil hydraulic properties in the humid Ethiopian Highlands: The Anjeni watershed

“…These findings are in agreement with those of Adgo et al (2013) and Assefa (2007) who found similar results for the Anjeni Watershed (Table 1). Likewise, these results (Table 1) concur with several authors who concluded that soils in the Ethiopian highlands are acidic (Chibsa and Ta, 2009;Demelash and Stahr, 2010;Feoli et al, 2002) and that its soil organic carbon pool is depleted (Hailu et al, 2012;Taddese, 2001;Zeleke et al, 2004). Soil acidity in the region is partly due to continuous weathering processes and leaching of base cations (Amare et al, 2013;Hodnett and Tomasella, 2002), while depletion of soil organic carbon is further acerbated by scarcity of farm inputs (including organic biomass) among other factors (Abegaz and Van Keulen, 2009;Feoli et al, 2002;Taddese, 2001).…”

Conservation Effects on Soil Quality and Climate Change Adaptability of Ethiopian Watersheds

“…In contrast, several researchers (e.g. Million, ; Demelash & Stahr, ; Gebreselassie et al ., ; Mekuria et al ., ; Hailu et al ., ; Amare et al ., ) reported significant differences in SOC concentration among soils with and without SWC treatment.…”

“…Shiene () also observed a significant increase in SOC concentration with an increase in slope gradient in northeast Ethiopia (in the North and South Wello zones of the Amhara region). Other researchers (e.g., Assefa, ; Hailu et al ., ; Amare et al ., ) reported an opposite trend of SOC concentration against slope. In the non‐conserved sub‐watershed, on the other hand, the highest SOC concentration was observed on the crest slope and the lowest on the foot slope.…”

Conservation and production impacts of soil and water conservation practices under different socio-economic and biophysical setting: a review

“…Other methodological error is that, not to accounted land loss by physical SWC practices which ranges from 8 to 15%. Vancampenhout et al (2006), Nyangena and Köhlin (2008), Alemayehu et al (2006), Hailu et al (2012) and Damene, (2012) classify watershed in to upper and lower and to different slope class and fail to consider individual farm variability. In this regard Abay (2011) reported increase of crop yield due to SWC practices differs from farmer to farmer as the management of soil is different among different farmers.…”

“…Many said nothing about maintenance of SWC in their study area (Hailu et al, 2012;Mihrete, 2014;Challa et al, 2016) and age of SWC practices (Alemayehu et al, 2006). Management practice such as increasing the height of bunds can influence bund effectiveness (Nyssen et al, 2007).…”