Table of Contents
ISRN Soil Science
Volume 2013, Article ID 748561, 10 pages
http://dx.doi.org/10.1155/2013/748561
Research Article

Assessing Sediment-Nutrient Export Rate and Soil Degradation in Mai-Negus Catchment, Northern Ethiopia

1College of Agriculture, Aksum University, Shire Campus, P.O. Box 314, Shire, Ethiopia
2Center for Development Research, University of Bonn, Walter-Flex-Straße 3, 53113 Bonn, Germany

Received 13 April 2013; Accepted 12 May 2013

Academic Editors: T. J. Cutright, J. A. Entry, M. Goss, C. Martius, and W. R. Roy

Copyright © 2013 Gebreyesus Brhane Tesfahunegn and Paul L. G. Vlek. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Even though soil degradation challenges sustainable development, the use of degradation indicators such as nutrient export (NE) and nutrient replacement cost is not well documented at landform level. This study is aimed to investigate the extent of soil degradation, NE rates, and their replacement cost across landforms in the Mai-Negus catchment, northern Ethiopia. Different erosion-status sites (aggrading, stable, and eroded) in the landforms were identified, and soil samples were randomly collected and analysed. Nutrient export, replacement cost, and soil degradation were calculated following standard procedures. This study showed that soil degradation in the eroded sites ranged from 30 to 80% compared to the corresponding stable site soils, but the highest was recorded in the mountainous and central ridge landforms. Average NE of 95, 68, 9.1, 3.2, 2.5, and 0.07 kg ha−1 y−1 for soil calcium, carbon, nitrogen, potassium, magnesium, and phosphorus, respectively, was found from the landforms. Significantly strong relationships between NE and sediment yield in the landforms were observed. Annual nutrient replacement costs varied among the landforms though the highest was in the reservoir (€9204 in May 2010). This study thus suggests that while introducing antierosion measures, priority should be given to erosion sources to the reservoir such as mountainous and central ridge landforms.