Kahsay, Araya , Yebyo, Selama Gebreslassie , Gebremedhin, Yohannes Gerezihier
2025-12-01 GEODERMA REGIONAL 2025 43(卷), null(期), (null页)
Soil erosion is one of the major degradation processes posing far-reaching threats to production sustainability and food security, associated with its marked contribution to soil quality degradation. There have been substantial studies on nutrient losses by erosion in Ethiopia, but rarely have the redistribution/deposition process been considered. In this study, we compared soil and nutrient loss of shrublands, grasslands and croplands to examine their sensitivity to erosion and deposition and land use managements. Quantification of soil erosion and deposition was achieved through Unit Stream Power Soil Erosion and Deposition model. Furthermore, soil organic carbon (SOC), total nitrogen (TN) and available phosphorus (AP) concentrations of the three land use managements were measured and analyzed to 30 cm depth. The results exhibited that soil and nutrient loss and their associated cost were heavily explained by variations in land use management. The magnitude of soil eroded far exceeded that of deposited in croplands and grasslands, while it was almost comparable to deposition rate in shrublands. Nutrient stocks in shrublands were higher than those in grasslands and croplands. Land use contributions to nutrient loss showed the orders of grasslands (4.22 Gg) > croplands (3.91 Gg) > shrublands (0.71 Gg). Out of the total nutrients transported by erosion (i.e. 16.78 Gg), ca. 47.47 % (7.96 Gg) is left redistributed within the area through deposition, with the remaining 8.81 Gg (52.53 %) leaving the area. Nutrient loss due erosion is causing to an average annual economic loss of about 7.95 million US$, > 90 % of which is contributed by grasslands and croplands, while that shared by shrublands was relatively small. Results implied the importance to consider erosion and deposition processes while assessing soil and nutrient depletion to precisely assess economic implications of erosion. Grasslands and croplands are more prone to erosion than shrublands, emphasizing the need to consider for improved cultivation and grazing managements to monitor soil quality degradation induced through erosion.