Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation measures to tackle the problem where farmland terracing i...Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation measures to tackle the problem where farmland terracing is one of the commonly implemented measures in the country. The purpose of this study was to analyze the role of farmland terracing in maintaining soil fertility and to evaluate its performance within a terrace, across terrace age and slope of terrain. The study was conducted in the Lake Maybar watershed in Wello, northern Ethiopia. Composite topsoil samples were collected from plots representing four slope categories across the terrain and three positions within a terrace. The samples were analyzed for selected soil physico-chemical properties and statistically tested using ANOVA （analysis of variance）. The study revealed that soil pH （△pH [H2O] = 0.6）, exchangeable K＋ （△K＋ = 0.33 cmol（＋）/kg） and clay （9%） content significantly increased towards the lower terrain position. Unlike other studies, all soil properties except bulk density （△ 0.40 g/cm3） showed non-significant differences within a terrace. Bench terrace formation reduced soil fertility gradients within a terrace for which it has been commented. Soil fertility also showed very slight change across terrace age, which indicates terracing reduced erosion-induced soil and nutrient loss. However, in order to optimize impact of farmland terracing on soil fertility maintenance, terracing should be complemented by fertility amendment considering site-specific conditions.展开更多
文摘Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation measures to tackle the problem where farmland terracing is one of the commonly implemented measures in the country. The purpose of this study was to analyze the role of farmland terracing in maintaining soil fertility and to evaluate its performance within a terrace, across terrace age and slope of terrain. The study was conducted in the Lake Maybar watershed in Wello, northern Ethiopia. Composite topsoil samples were collected from plots representing four slope categories across the terrain and three positions within a terrace. The samples were analyzed for selected soil physico-chemical properties and statistically tested using ANOVA （analysis of variance）. The study revealed that soil pH （△pH [H2O] = 0.6）, exchangeable K＋ （△K＋ = 0.33 cmol（＋）/kg） and clay （9%） content significantly increased towards the lower terrain position. Unlike other studies, all soil properties except bulk density （△ 0.40 g/cm3） showed non-significant differences within a terrace. Bench terrace formation reduced soil fertility gradients within a terrace for which it has been commented. Soil fertility also showed very slight change across terrace age, which indicates terracing reduced erosion-induced soil and nutrient loss. However, in order to optimize impact of farmland terracing on soil fertility maintenance, terracing should be complemented by fertility amendment considering site-specific conditions.
