Linking soil erosion to onsite financial cost: lessons from watersheds in the Blue Nile basin

Abstract

Abstract. The study was conducted in three watersheds (Dapo, Meja and Mizewa) in the Ethiopian part of the Blue Nile Basin to estimate the onsite cost of soil erosion using the productivity change approach, in which crop yield reduction due to plant nutrients lost with the sediment and runoff has been analyzed. For this purpose, runoff measurement and sampling was conducted during the main rainy season of 2011 at the outlet of two to three sub watersheds in each watershed. The sediment concentration of the runoff, and nitrogen and phosphorus content of the runoff and sediment were determined. Crop response functions were developed for the two plant nutrients based on data obtained from the nearest Agricultural Research Centers. The response functions were used to estimate crop yield reduction as a result of the lost N and P assuming there is no compensation through fertilization. The results show a significant yield reduction and resultant financial loss to the farmers. Considering only grain yield of maize (Zea mays), farmers at Dapo annually lose about 220 and USD 150 ha-1 due to the loss of nitrogen and phosphorus, respectively. In view of the importance of the crop residues including as feed, the loss can be even greater. The study demonstrated that in addition to the long-term deterioration of land quality, the annual financial loss suffered by farmers is substantial. Therefore, on farm soil and water conservation measures that are suitable in biophysical and socio-economic terms in the landscapes and beyond need to be encouraged.

Evaluating erosion control practices in an actively gullying watershed in the highlands of Ethiopia

“…Although erosion is a natural process, when accelerated by human mismanagement of land resources, it results in soil and land degradation and reductions in forest and agricultural productivity (García-Orenes et al, 2012;Sop and Oldeland, 2013). This land degradation and the associated nutrient depletion of soil resources have profound economic implications for low-income countries (Yitbarek et al, 2012;Erkossa et al, 2015). Soil erosion by water is a particularly critical problem in the high-rainfall Ethiopian highlands.…”

Empirical Sediment Transport Models Based on Indoor Rainfall Simulator and Erosion Flume Experimental Data

“…Land degradation is due to a complex mix of causes; some may be natural and some human-induced (Xu & Zhang, 2014;Xie et al, 2015). Increase in soil erosion not only causes soil quality degradation because of loss of topsoil as a result of soil quality degradation in an irreversible direction but also lead to catastrophic floods, droughts and famine threatening food and environmental security worldwide (Erkossa et al, 2015;Musinguzi et al, 2015;Stanchi et al, 2015;Tsozué et al, 2015;Ochoa et al, 2016). It is important to keep in mind that the transportation of sediment to water bodies is accompanied by loss of nutrients from farmlands, which results in infertile farmlands and eutrophicated freshwater (Vanacker et al, 2003), meaning also that croplands are lost because of soil erosion as the soil loss rate is much faster than the soil renewal rate (Pimentel, 2006;Bravo-Espinosa et al, 2014;Li et al, 2014;Wang et al, 2016).…”

An Indigenous Soil Bacterium Facilitates the Mitigation of Rocky Desertification in Carbonate Mining Areas

“…Soil erosion, bedrock exposure and land productivity loss caused by excessive human activities and the erosion effects of rainfall runoff aggravate rocky landscapes on Earth (Erkossa et al, 2008;Ochoa-Cueva et al, 2015;Prosdocimi et al, 2016;Rodrigo et al, 2016), which is referred to as the rocky desertification phenomenon (Huang et al, 2016). The rocky desertification of rock mining areas caused via overexploitation is a specific type of rocky desertification (Xu et al, 2013).…”