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Abiyu A.,Amhara Agricultural Research Institute | Abiyu A.,University of Natural Resources and Life Sciences, Vienna | Teketay D.,University of Botswana | Glatzel G.,University of Natural Resources and Life Sciences, Vienna | And 2 more authors.
Southern Forests | Year: 2017

The scale of deforestation in sub-Saharan Africa underscores the need for forest restoration. Information is scarce for evidence-based restoration options. Sown Senna didymobotrya, planted Ficus thonningii cuttings, sown S. didymobotrya and planted F. thonningii combined, and previously occurring native non-browse shrubs (NNS) were compared for their effect on selected plant nutrients and occurrence of Olea europaea subsp. cuspidata in north-west Ethiopia. The treatments were applied to experimental units established on previous grazing land. At the end of the fourth year, 60% of planted F. thonningii stakes survived. The leaf biomass production was encouraging. Senna didymobotrya attained close to 1 m height and crown width. Natural regeneration of O. europaea was observed only under previously occurring shrubs. Six previously occurring NNS species were identified. Soils immediately under these shrubs were richer in nutrients than between shrubs in the open spaces. Our results suggest that vegetative stakes and NNS could be promising tools for ecological restoration of decimated ecosystems in the highlands of Ethiopia. Management interventions, which aim at steering succession close to pre-disturbance forest community structure by facilitation, should be selective of the shrub species. © 2017 NISC (Pty) Ltd

Assefa D.,University of Natural Resources and Life Sciences, Vienna | Rewald B.,University of Natural Resources and Life Sciences, Vienna | Sanden H.,University of Natural Resources and Life Sciences, Vienna | Rosinger C.,University of Natural Resources and Life Sciences, Vienna | And 3 more authors.
Catena | Year: 2017

Soil is the largest terrestrial organic carbon pool and can act as a source or sink for atmospheric CO2. Although reliable soil carbon (SOC) stock measurements of major ecosystems are essential for predicting the influence of advancing climate change, comprehensive data on SOC stocks is still scarce for most ecosystems in subtropical areas. In this study, SOC and N stocks of different land use systems were investigated along a climatic gradient in Northwest Ethiopia. The land use systems ranged from dry subtropical Afromontane forest, as the baseline, to cropland as the most degraded system. In addition, we investigated the changes of SOC stocks after interventions to recover vegetation cover; these were eucalyptus plantations and an exclosure to prevent grazing. Total SOC varied between land use systems and ranged from 3.1 kg C m− 2 in croplands to 23.9 kg C m− 2 in natural forest, and average N stock ranged from 0.4 kg N m− 2 in croplands to 2.1 kg N m− 2 in natural forest. In forests, there were a clear vertical gradient in SOC and N stock down the soil profile, and 60% of the total SOC and N stocks were found in the upper 10 cm soil depth. Using the Sr/Ca and Ba/Ca ratios and the vertical distribution of the C/N ratio of the soil, the losses of SOC were shown to be due to loss of the of the upper soil layer. Afforestation of degraded croplands and grazing lands with eucalyptus increased SOC stocks to nearly 70% of the natural forest levels within 30 years. Exclosure, which removed grazing pressure and allowed regeneration of native vegetation, increased SOC in the top soil only. © 2017

Adgo E.,Bahir Dar University | Adgo E.,Tottori University | Teshome A.,Amhara Agricultural Research Institute | Mati B.,Improved Management of Agricultural Water in Eastern and Southern Africa IMAWESA
Agricultural Water Management | Year: 2013

Over the last three decades, many soil and water conservation projects have been implemented in various parts of eastern and southern Africa to control land degradation, and improve land productivity, especially under 'catchment approach' initiatives of the 1980s. In Ethiopia, many of these soil conservation projects were implemented following the severe drought of 1974. To capture long-term impacts of these initiatives, a study was conducted in Anjenie Watershed of Ethiopia, assessing fanya juu terraces and grass strips constructed in a pilot project in 1984, and which are still functional 25 years later. Data were collected from government records, field observations and questionnaire surveys administered to 60 farmers. Half of the respondent had terraced farms in the watershed former project area (with technology) and the rest were outside the terraced area (without technology). The crops assessed were teff, barley and maize. Cost-benefit analyses were used to determine the economic benefits with and without terraces, including gross and net profit values, returns on labour, water productivity and impacts on poverty.The results indicated that soil and water conservation had improved crop productivity. The average yields on terraced fields for teff, barley and maize were 0.95tha-1 (control 0.49), 1.86tha-1 (control 0.61), and 1.73tha-1 (control 0.77), respectively. The net benefit was significantly higher on terraced fields, recording US$ 20.9 (US$ -112 control) for teff, US$ 185 (US$ -41 control) for barley and US$ -34.5 (US$ -101 control)ha-1yr-1 for maize, respectively. The returns on family labour were 2.33, 1.01 and 0.739US$man-day-1 for barley, teff and maize grown on terraced plots compared to US$ 0.44, 0.27 and 0.16man-day-1 for without, respectively. Using a discount rate of 10%, the average net present value (NPV) of barley production with terrace was found to be about US$ 1542 over a period of 50 years. In addition, the average financial internal rate of return (FIRR) was 301%. Other long-term impacts of terracing included farmers' growing of maize on terraced fields as a result of water conservation. Currently, farmers also grow barley on terraced fields for two crop seasons per year unlike the experiences on farms without terraces. Household incomes and food security had improved and soil erosion drastically reduced. Many farmers had adopted terracing doubling the original area under the soil conservation pilot project and consequently improving environmental conservation in the watershed. © 2012 Elsevier B.V.

Abiyu A.,Amhara Agricultural Research Institute | Abiyu A.,University of Natural Resources and Life Sciences, Vienna | Abiyu A.,Friedrich - Alexander - University, Erlangen - Nuremberg | Dejene T.,Ethiopian Environment and Forestry Research Institute | And 3 more authors.
Journal of Arid Environments | Year: 2016

In the dry woodlands of Africa, stem cuttings of some tree species can root easily for successful vegetative propagation. Successful rooting and establishment of planted cuttings can be affected by size of cutting, planting season, age of parent stock and part of plant used. Propagule length and four collection times were studied on their effect on the survival of branch cuttings of Boswellia papyrifera over a six-year period. The study was carried in a semi-arid area of northwest Ethiopia, where the rainfall occurs from June to September and the other part of the year being too dry to normal plant physiological functioning. Collection time, cutting length and their interaction showed significant differences in mean survival rate. The higher mean survival value was observed from those cutting materials collected in May. The weakest performance was observed from those cutting materials collected in October. The observed difference may be effect of phenological calendar of the species, especially the effect of dormancy period and leaf bud breaking times. Longer stem cuttings did not show persistent better performance across time. This technique could be an alternative solution for restocking the declining B. papyrifera population and fast restoration of degraded dry lands. © 2016 Elsevier Ltd

Abebe T.,Amhara Agricultural Research Institute | Wongchaochant S.,Kasetsart University | Taychasinpitak T.,Kasetsart University
Kasetsart Journal - Natural Science | Year: 2013

The phenotypic diversity of 25 potato varieties was analyzed at three distinct locations in the Amhara region of Ethiopia with the main objective of determining the diversity present among them based on 11 quantitative and 18 qualitative morphological characteristics. The field experiment was laid out in a 5 × 5 balanced lattice design with six replications. The results of analysis of variance indicated highly significant (P < 0.01) differences among varieties for all 11 quantitative characteristics considered. Furthermore, analysis of the average taxonomic genetic distance based on 18 qualitative characteristics using the Euclidean distance function revealed considerable divergence among the studied varieties. Accordingly, the genetic distance value ranged from 0.24 between Tolcha and Wochecha, European commercial varieties, to 0.72 between the farmer's variety Ater Abeba and the improved variety Zengena. The 25 varieties were grouped into three main clusters based on the distance matrix following the hierarchical agglomerative clustering method known as UPGMA (unweighted pair group method with arithmetic mean). Cluster I, which was the largest, contained 18 varieties followed by clusters II and III, with 3 and 4 varieties, respectively. Thus, this study revealed the presence of sufficient phenotypic diversity among varieties in the country that can be exploited for germplasm enhancement.

Abebe T.,Amhara Agricultural Research Institute | Wongchaochant S.,Kasetsart University | Taychasinpitak T.,Kasetsart University
Kasetsart Journal - Natural Science | Year: 2013

Potato starches isolated from 25 different varieties grown at three different locations in the Amhara region of Ethiopia in 2011 were studied to determine their variation based on amylose content (AMC) and amylopectin content (APC), and pasting properties by iodine colorimetry and Rapid Visco Analyzer procedures, respectively. The results revealed highly significant (P < 0.01) differences between cultivar and location. The mean values for the AMC and APC ranged from 20.86% (Jalene) to 30.58% (Ater Abeba), and 69.42% (Ater Abeba) to 79.14% (Jalene), respectively. The mean AMC index of locations ranged from 24.50% to 26.24% for the Adet and Debretabor sites. The peak viscosity (PV), hot paste viscosity (HPV), breakdown viscosity (BDV), cool paste viscosity (CV) and setback viscosity (SBV) ranged from 225.10 to 426.72, 135.01 to 191.83, 56.47 to 259.32, 173.68 to 247.51 and 27.17 to 68.15 Rapid Visco units (RVU), respectively, while the pasting time (PT) and pasting temperature (Ptemp) ranged between 3.35 to 4.91 minutes and 68.16 to 70.89 °C, respectively. Correlation among starch properties showed significant (P < 0.01 and P < 0.05) associations except for PV with CPV and HPV with BDV and SBV. The highest PV (538 RVU), HPV (207 RVU), BDV (363 RVU), and CV (265 RVU) values were recorded at the cool Debretabor site. Thus, the study revealed the significant genetic variation present among varieties with regard to the starch chemical composition and pasting properties and the effects of growing location on these properties.

Abebe T.,Amhara Agricultural Research Institute | Wongchaochant S.,Kasetsart University | Taychasinpitak T.,Kasetsart University
Kasetsart Journal - Natural Science | Year: 2013

Specific gravity (SG) is the measure of choice for estimating dry matter (DMC) and starch content (SC) and ultimately for determining the processing quality of potato varieties. Evaluation of the SG of 25 potato varieties was carried out at three distinct locations in the Amhara region of Ethiopia with the main objectives of determining their culinary quality and most suitable areas of production. The varieties were planted in a 5 × 5 balanced lattice design of six replications during the 2011 rainy season. The results of the data analysis showed highly significant (P < 0.01) genotypic and location differences and significant (P < 0.05) genotype × environment interactions. The pooled SG values ranged from 1.058 to 1.102. The SG of tubers of the improved variety Belete was the highest while that of Menagesha was the lowest. Furthermore, the SG values for varieties grown at Debretabor were higher than those for the corresponding varieties grown at Adet and Merawi. The DMC and SC were computed based on the SG and showed significant (P < 0.01) genotypic variability. The highest DMC and SC were also obtained at Debretabor; thus, it is an ideal location to grow potatoes for high DMC and starch accumulation. Additive main effects and multiplicative interaction analysis identified CIP-392640.524, Zengena, Jalenie and Belete as stable genotypes with SG values above average.

Abebe T.,Amhara Agricultural Research Institute | Wongchaochant S.,Kasetsart University | Taychasinpitak T.,Kasetsart University | Leelapon O.,National Center for Genetic Engineering and Biotechnology
Kasetsart Journal - Natural Science | Year: 2012

The extent of genetic variation in the protein and fiber contents and the iron (Fe), zinc (Zn) and phosphorus (P) concentrations of 21 different potato varieties was studied at two distinct locations in Ethiopia. The experiments were conducted in a randomized complete block design in triplicate. Analysis of variance (ANOVA) of each set of experimental data revealed significant (P < 0.01) genetic variation among varieties. The combined ANOVA also showed significant (P < 0.01) variation due to location and genotype × location interactions. Accordingly, the tuber protein and fiber contents ranged from 3.77 to 7.36% and 1.18 to 2.07%, respectively. Likewise, the Fe, Zn and P concentrations ranged from 17.13 to 164.83, 7.07 to 20.21 and 143.68 to 357.76 mg.kg-1 dry weight, respectively. Consequently, men, women, and children can get 29, 13.3 and 65%, respectively, of their daily recommended nutrient intake (RNI) of Fe from eating 200 g fresh weight of tubers of the high Fe concentration variety Sisay and 12, 14.3 and 17%, respectively, of their daily RNI of Zn from 200 g of tuber of the high Zn variety Menagesha. Correlation analysis indicated a significant (P < 0.01) association among these characters but not with protein and fiber with Fe. Thus, this study found considerable variation in the mineral concentrations among potato varieties in Ethiopia which can be useful information to help curb mineral malnutrition.

Abebe T.,Amhara Agricultural Research Institute | Wongchaochant S.,Kasetsart University | Taychasinpitak T.,Kasetsart University | Leelapon A.O.,National Center for Genetic Engineering and Biotechnology
Kasetsart Journal - Natural Science | Year: 2012

Evaluation of dry matter content (DMC), starch content (SC) and starch yield (SY) of 25 potato varieties was carried out at three distinct locations in the Amhara region of Ethiopia during the 2011 cropping season. The main objectives were to examine the variability and stability of these traits and determine the proper production environments. The 25 varieties were examined in a complete 5 × 5 lattice design with six replications. Statistical analyses of the DMC, SC and SY of these varieties revealed signifi cant (P < 0.01) genotypic and location variation and genotype × environment interactions. Consequently, their DMC and SC ranged from 17.82 to 26.70 and 9.75 to 17.85%, respectively, while SY ranged from 2.21 to 6.91 t.ha-1. Correlation analysis revealed a strong linkage (P < 0.01) among these characters. Additive main effects and multiplicative interactions analysis for DMC and SC stability identifi ed Gorebella, Ater Abeba, Challa, Belete and CIP-396004.337 as relatively stable for processing while Menagesha, Bulle, Ararsa were suitable for table purposes. Furthermore, Debretabor followed by Adet were found suitable for producing processing types while Merawi was suitable for table types. Thus, this study distinctly separated varieties and environments on the one hand and the available genetic resources for a breeding program aimed at improving DMC and SY of potato in Ethiopia on the other.

Steenhuis T.S.,Cornell University | Steenhuis T.S.,Bahir Dar University | Hrncir M.,Czech Technical University | Poteau D.,Cornell University | And 9 more authors.
Vadose Zone Journal | Year: 2013

Since Hewlett and Hibbert's publication in 1967, there has been a slow recognition that saturated excess runoff is the main runoff mechanism in vegetated watersheds. Yet, most pedotransfer functions for predicting runoff are based on infiltration excess runoff. We, therefore, developed a simple pedotransfer function to predict saturation excess runoff, using data from eight watersheds on three continents. The runoff response was very similar for all watersheds, despite differences in climate, size, topography, and land use. Direct storm runoff occurred after a threshold amount of rainfall was exceeded. Runoff was linearly related to rainfall depth, indicating that a nearly constant proportion of the watershed was the source area. Size of source areas decreased with increasing depths of soils. The rainfall threshold was strongly dependent on the initial moisture conditions. The developed pedotransfer function for saturation excess runoff was used to predict water level fluctuation of two terminal lakes on the Caribbean Islands over a 25- to 30-yr period with the rainfall threshold computed following Thornthwaite-Mather and baseflow from the remaining part of the watershed employing a linear reservoir model. Taking the simplicity of the prediction technique with only four calibrated parameters into account, lake levels were predicted reasonably well to very good, including the rise in the lake level in the last 10 yr when the climate in the region became wetter. It is expected that the linear relationship of rainfall and runoff holds for storms lasting several days and can simplify flood predictions. © Soil Science Society of America, All rights reserved.

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