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Gully erosion often indicates extreme land degradation. In the highlands of Ethiopia, wide and deep gullies are common features, significantly affecting land used for agriculture. However, little action is being taken to address the problem. Where rehabilitation actions in Ethiopia are taking place, they are rarely studied by financially quantifying their costs and benefits. Therefore, this study developed methods of quantifying gully erosion costs and rehabilitation costs and benefits by considering the soil components of four model rehabilitated gullies in Ethiopia. Data were obtained from a physical survey supported by secondary information from relevant agricultural offices. Quantification was achieved by monetizing gully erosion cost through yield loss and gully rehabilitation calculations according to expenditure, while rehabilitation benefits were obtained by monetizing estimated deposited soil nutrients using fertilizer prices. Cost‐benefit values show that investment in gully rehabilitation can be an economically viable proposition in some instances. Stakeholders involved in gully rehabilitation should continue to invest in appropriate techniques of gully rehabilitation and management to ensure continued benefits from rehabilitated gullies and use of surrounding farmlands. Copyright © 2010 John Wiley & Sons, Ltd.

Knowledge of the kinds and properties of soils is critical for making decisions with respect to crop production and other land use types. A field survey and soil morphological description and laboratory analysis were carried out to describe, characterize, and classify the soils of Abobo area, western Ethiopia. Seven representative pedons (A-1 to A-7) were opened and described across the study area. The results revealed variation in morphological, physical, and chemical properties of the soils. The soils are clay loam to clayey in texture with bulk density values ranging from 1.12 to 1.32 g cm−3 and basic infiltration rate varying from slow to moderate (0.4 to 3.3 cm hr−1). They were moderately acidic to neutral in pH (5.5 to 7.1) and had very low to medium organic carbon (OC) (0.27 to 2.98%). Four soil types, Haplic Cambisols, Vertic Luvisols, Mollic Leptosols, and Mollic Vertisols, were identified in the area based on World Reference Base. Generally, the properties of the soils differed along the transect indicating their variation in productive potential and management requirements for specific agricultural use.

Land suitability assessment plays an important role in identifying biophysical constraints and evaluating potential capacity of land and its sustainable use. Physical land suitability evaluation for irrigation was carried out in the lower Alwero river area of Abobo, western Ethiopia, following FAO methodology for general irrigation farming. The irrigation suitability of five land mapping units (LMUs): 1Ac, 1Bc, 1Ecl, 2Cc and 3Ccl were assessed by considering slope, drainage, top soil texture, sub soil texture, surface stoniness, surface coarse fragments, subsurface coarse fragment, rockiness, depth to solid rock or hardpan, lime, gypsum, electrical conductivity (EC) and exchangeable sodium percentage (ESP). The result revealed that LMU 1Ac, 1Bc and 2Cc, with total area of 22,367.9 ha (83.7%), were moderately suitable (S2). The moderate limiting factors were drainage, top soil texture and subsoil texture. On the other hand, LMU 1Ec1, covering an area of 3,677.6 ha (13.8%) was not suitable (N) for irrigation due to subsurface coarse fragments and depth to solid rock or hardpan. For all LMUs, parameters like lime, gypsum, EC and ESP were not considered as limiting factors.

The main purpose of this study was to characterize and classify soils of Wolkite University research sites, Gurage zone, Ethiopia. In each five research sites, Wabe (RS1), Geche (RS2), Yefereze (RS3), Kotergedra (RS4) and Keratemo (RS5), representative pedons were opened and described. Almost all the pedons were deep (>150 cm) with argillic B horizons and had clay textural class. The pH of the surface soils ranged from strongly acidic (4.5) to moderately acidic (5.6). The soils had medium (2.60%) to high (3.84%) organic carbon content and very low (1.46 mg kg-1) to low (10.34 mg kg-1) available phosphorus. The status of cation exchange capacity (CEC) and base saturation were ranged from medium (23.15) to very high (66.32 cmolc kg-1) and low (33%) to high (99%), respectively. According to WRB classification, pedon RS1 was classified as Haplic Vertisols (Hypereutric) with USD equivalent of Typic Haplusterts. Pedons RS2 and RS3 were classified as Vertic Alisols (Hyperdysric), which is correlated with Ultisols (Typic Haplustults) in USDA classification. Pedon RS4 and RS5 classified as Vertic Luvisols (Hypereutric), which is correlated with Alfisols (Vertic Haplustalfs) in USDA classification. Generally, the soils of the research sites were acidic with low status of available phosphorus, which need amelioration of soil acidity and nutrient management.

In addressing land degradation, a number of watershed rehabilitation programs have been carried out in Ethiopia. This study aims to financially quantify watershed rehabilitation in a way that incorporates major costs and returns. We also construct scenarios to portray cost-benefit information about the future. The data were obtained from a physical survey and supplemented with secondary sources. Total cost and return values for the watersheds were compared monetarily through cost-benefit analysis and these values were extrapolated to the future. The results indicate that the benefit was , while the costs remain the same. The results clearly indicate that investment in watershed rehabilitation may be an economically viable short-term and long-term proposition. Hence there is a strong case for sustainable management of rehabilitated watersheds in view of the very high economic benefits from the rehabilitation.

One of the main reasons for Ethiopia’s declining agricultural production is land use change under poor soil management practices. Hence, in order to evaluate the effects of various land use types on certain soil qualities, research was done on the soils of Cheha district, Gurage zone in Ethiopia’s central highlands. Four different land use types (LUTs) (cultivated, enset, eucalyptus, and wild forest) were used for this study to assess and analyze their response to soil fertility. A total of 48 soil samples (24 undisturbed and 24 disturbed) was collected from the selected LUTs and two different soil depths (SDs) (0-20 and 20-40 cm) with three replications for the laboratory analysis. The results showed that most of the properties of soil physicochemical properties of soil were significantly affected by LUTs, SD, and the interactions. The result showed that the highest sand (43%), silt (46.5%), and clay (30.30%) fractions were observed under forest land (FL), enset farmland (ENFL), and cultivated land (CUL), respectively. Concerning the SD, higher silt (40.9%) and clay (28.3%) were found in the subsurface soils. Except for CUL, textural classes of all LUTs were loamy. The highest (1.37 g cm-3) bulk density was observed under the subsurface soils of CUL and the lowest (1.06 g cm-3) was in the surface soils of FL and ENFL. In contrast to bulk density, total porosity was highest (60.1%) under surface soils of FL and ENFL and the lowest (48.3%) value was observed under subsurface soils of CUL. The combination of two factors influenced the soil pH. The highest value (6.54) and lowermost (4.82) values were found under the surface soils of ENFL and subsoils of EUCL, respectively. Comparatively, the uppermost (7.48%) and lowermost (3.55%) values of organic matter were recorded under the surface soils of FL and subsoils of EUCL. The uppermost (0.37%) and lowermost (0.17%) values of total nitrogen were registered under surface soil and subsoils of FL and EUCL, respectively. The uppermost (22.69 mg kg-1) value of Av.P was registered under superficial soils of ENFL and the lowermost (5.02 mg kg-1) was obtained under a subsurface layer of EUCL. The uppermost (37.96 cmol(+) kg-1) and lowermost (11.90 cmol(+) kg-1) of CEC values were observed under the surface soils of FL and subsoils of EUCL. The uppermost value of exchangeable acidity (1.85 cmol(+) kg-1) was recorded under soils of EUCL. This study showed that different LUTs and SDs have substantial impacts on the status of soil fertility. Soils of FL and ENFLs were relatively more fertile. Increasing eucalyptus tree cover on arable land and intensive farming severely impacted soil fertility which may have increased soil acidity. Appropriate land use and a variety of soil fertility management practices are crucial to address soil fertility loss and acidity issues

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