Your search found 9 records
1 Belay, S. A.; Assefa, T. T.; Prasad, P. V. V.; Schmitter, Petra; Worqlul, A. W.; Steenhuis, T. S.; Reyes, M. R.; Tilahun, S. A. 2020. The response of water and nutrient dynamics and of crop yield to conservation agriculture in the Ethiopian highlands. Sustainability, 12(15):5989. [doi: https://doi.org/10.3390/su12155989]
Conservation agriculture ; Water use ; Nutrient availability ; Crop yield ; Highlands ; Supplemental irrigation ; Conventional tillage ; Irrigation water ; Water management ; Crop management ; Pepper ; Growth period ; Fertilizers ; Phosphorus ; Nitrogen ; Leachates ; Rain ; Runoff ; Evapotranspiration / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H049873)
(2.48 MB) (2.48 MB)
Smallholder agriculture constitutes the main source of livelihood for the Ethiopian rural community. However, soil degradation and uneven distribution of rainfall have threatened agriculture at present. This study is aimed at investigating the impacts of conservation agriculture on irrigation water use, nutrient availability in the root zone, and crop yield under supplementary irrigation. In this study, conservation agriculture (CA), which includes minimum soil disturbance, grass mulch cover, and crop rotation, was practiced and compared with conventional tillage (CT). We used two years’ (2018 and 2019) experimental data under paired-t design in the production of a local variety green pepper (Capsicum annuum L.). The results showed that CA practices significantly (a = 0.05) reduced irrigation water use (13% to 29%) and runoff (29% to 51%) while it increased percolated water in the root zone (27% to 50%) when compared with CT practices under the supplementary irrigation phase. In addition, CA significantly decreased NO3-N in the leachate (14% to 44%) and in the runoff (about 100%), while PO4-P significantly decreased in the leachate (33% to 50%) and in the runoff (16%) when compared with CT. Similarly, CA decreased the NO3-N load in the leachate and in the runoff, while the PO4-P load increased in the leachate but decreased in the runoff. The yield return that was achieved under CA treatment was 30% higher in 2018 and 10% higher in 2019 when compared with the CT. This research improves our understanding of water and nutrient dynamics in green pepper grown under CA and CT. Use of CA provides opportunities to optimize water use by decreasing irrigation water requirements and optimize nutrient use by decreasing nutrient losses through the runoff and leaching.
2 Belay, S. A.; Assefa, T. T.; Worqlul, A. W.; Steenhuis, T. S.; Schmitter, Petra; Reyes, M. R.; Prasad, P. V. V.; Tilahun, S. A. 2022. Conservation and conventional vegetable cultivation increase soil organic matter and nutrients in the Ethiopian highlands. Water, 14(3):476. (Special issue: Hydrology and Sedimentology of Hilly and Mountainous Landscapes) [doi: https://doi.org/10.3390/w14030476]
Conservation agriculture ; Conventional tillage ; Soil organic matter ; Soil fertility ; Nutrients ; Highlands ; Vegetable crops ; Irrigation water / Africa South of Sahara / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H051088)
https://www.mdpi.com/2073-4441/14/3/476/pdf?version=1644302965
https://vlibrary.iwmi.org/pdf/H051088.pdf
https://vlibrary.iwmi.org/pdf/H051088.pdf
(1.69 MB) (1.69 MB)
Agriculture in Africa is adversely affected by the loss of soil fertility. Conservation agriculture (CA) was introduced to curb the loss of soil fertility and water shortages and improve crop productivity. However, information on how CA practices enhance soil quality and nutrients is scarce in the sub-Saharan Africa context. The objective of this study was to investigate the effects of CA and conventional tillage (CT) on soil organic matter and nutrients under irrigated and rainfed vegetable on-farm production systems. During the dry and wet monsoon phases in the northern Ethiopian Highlands, a four-year experiment with CA and CT was carried out on ten vegetable farms under rainfed and irrigated conditions. Although the increase in concentration of organic matter in CA was generally slightly greater than in CT, the difference was not significant. The average organic matter content in the top 30 cm for both treatments increased significantly by 0.5% a-1 from 3% to almost 5%. The increase was not significant for the 30–60 cm depth. The total nitrogen and available phosphorus concentrations increased proportionally to the organic matter content. Consequently, the extended growing season, applying fertilizers and livestock manure, and not removing the crop residue increased the nutrient content in both CA and CT. The increase in CA was slightly greater because the soil was not tilled, and hay was applied as a surface cover. Although CA increased soil fertility, widespread adoption will depend on socioeconomic factors that determine hay availability as a soil cover relative to other competitive uses.
3 Belay, A. M.; Assefa, T. T.; Belay, S. A.; Yimam, A. Y. 2023. Evaluating the performance of small-scale irrigation schemes in subhumid Ethiopian highlands. Irrigation and Drainage, 72(1):224-239. [doi: https://doi.org/10.1002/ird.2753]
Small-scale irrigation ; Irrigation schemes ; Irrigation water ; Performance assessment ; Highlands ; Subhumid zones ; Infiltration rate ; Crop water use ; Water requirements ; Water supply ; Indicators ; Water management ; Infrastructure / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H051702)
(0.72 MB)
This study was conducted to evaluate the performance of two small-scale irrigation (SSI) schemes in the subhumid Ethiopian highlands. Water application at the farm level and flow velocity along the main canal were monitored using a Parshall flume and current meter, respectively. The infiltration was measured at the head, middle and tail of the scheme within the command area using a double-ring infiltrometer. Soil samples were collected using an auger up to 60 cm in depth. Climatic and agronomic data were supplied to the crop water assessment tool (CROPWAT) to determine crop water requirements. The results showed that the average conveyance efficiency for the lined main canal was 90% and 92% for the Mugie and Fesas SSI schemes, respectively. The conveyance efficiency for the unlined main canal was in the order of 86% and 87% for the Mugie and Fesas SSI schemes, respectively. On the other hand, the average application efficiency and overall efficiency were found to be 56% and 51%, respectively, with a storage efficiency of 50% for the Mugie irrigation scheme. Similarly, the overall, application and storage efficiencies were 50%, 54% and 56%, respectively, for the Fesas irrigation scheme. Failure of operating gates, canal siltation and leakage through the main canals were the main causes of poor performance.
4 Assefa, T. T.; Taye, Meron Teferi; Ebrahim, Girma Yimer; Lautze, Jonathan; Seid, Abdulkarim Hussein. 2023. Water storages in Tana-Beles Sub-basin of Ethiopia: what do we know, and where should we go? SN Applied Sciences, 5:275. [doi: https://doi.org/10.1007/s42452-023-05499-1]
Water storage ; Water quality ; Energy ; Food security ; Ecosystems ; Nexus approaches ; Biodiversity ; Wetlands ; Reservoirs ; Groundwater ; Ponds ; Agricultural development ; Land degradation ; Sedimentation ; Climate change ; Population growth ; Economic growth ; Systematic reviews / Ethiopia / Tana-Beles Sub-Basin / Lake Tana
(Location: IWMI HQ Call no: e-copy only Record No: H052315)
https://link.springer.com/content/pdf/10.1007/s42452-023-05499-1.pdf?pdf=button
https://vlibrary.iwmi.org/pdf/H052315.pdf
https://vlibrary.iwmi.org/pdf/H052315.pdf
(2.28 MB) (2.28 MB)
The Tana-Beles sub-basin, a strategic economic growth corridor in Ethiopia, relies on water storage to provide a suite of key services to agriculture, drinking water supply, energy, and ecosystems. While there are a range of storage options (e.g., from large dams to subsurface aquifers) that can be utilized to provide these services, a systematic stock-take of literature on water storage in the Tana-Beles has not been undertaken. This knowledge gap constrains the identification of the relative contribution of different storage types in the Tana-Beles. Accordingly, in this study, we conducted a systematic review of literature on the surface and sub-surface storages to examine key issues of the different storage types and their linkages in the Tana-Beles sub-basin. Peer-reviewed and grey publications from various databases were considered for the systematic review. The results indicate that literature in the Tana-Beles sub-basin is more focused on natural storage like wetlands and Lake Tana than built storage types like human-made reservoirs. Overall, the analysis revealed three key points. First, storage volume and water quality in those storages are declining. Second, the causal factors for storage loss and water quality deterioration are agricultural expansion, land degradation, sedimentation, and increasing water withdrawals. Third, the storage gap will increase because of climate change, population, and economic growth while current management options are fragmented. Therefore, the need for more integrated nexus approaches is paramount to optimize storage resources in water, food, energy, and ecosystems in light of population-driven growth in demand and the ongoing global climate crisis.
5 Bizimana, J.-C.; Yalew, B. B.; Assefa, T. T.; Belay, S. A.; Degu, Y. M.; Mabhaudhi, Tafadzwanashe; Reyes, M. R.; Prasad, P. V. V.; Tilahun, Seifu A. 2023. Simulating potential impacts of solar MajiPump on the economy and nutrition of smallholder farmers in sub-humid Ethiopia. Water, 15(22):4003. [doi: https://doi.org/10.3390/w15224003]
Irrigation technology ; Solar powered irrigation systems ; Pumps ; Smallholders ; Farmers ; Economic aspects / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052562)
https://www.mdpi.com/2073-4441/15/22/4003/pdf?version=1700221598
https://vlibrary.iwmi.org/pdf/H052562.pdf
https://vlibrary.iwmi.org/pdf/H052562.pdf
(4.21 MB) (4.21 MB)
Irrigation is widely considered a potential means to improve agricultural productivity, nutrition, and income, as farmers can carry out farming and production year-round. However, the feasibility of irrigation technologies is highly dependent on the long-term economic return farmers achieve. Solar-based irrigation could address the challenges of underinvestment in irrigation within Africa. Evidence on the economic viability of the adopted solar pumps such as MajiPump is very scant and focused on ex post evaluation. This study evaluated the income and nutritional feasibility of solar-powered irrigation using the MajiPump in sub-humid Ethiopian highlands using the farm simulation (FARMSIM) model and compared it with the manual pulley system. Results from the FARMSIM model show that farmers’ adoption of Maji solar pump technology to grow vegetables is economically feasible with financial support such as credit or loan for initial and capital investment to acquire the pump. The average profit under the solar MajiPump, drip irrigation, and conservation agriculture was 3.6 times higher than that of the baseline scenario. While the pulley technology provides the same amount of irrigation water to grow vegetables, its feasibility is limited due to high labor costs and time, estimated to be more than seven times the baseline. The simulation results show that the alternative scenarios’ nutrition level has improved relative to other scenarios and met the minimum daily average nutrition requirement level for proteins, iron, and vitamin A but fell short in fat, calcium, and calories. The results suggest that farmers who adopt improved small-scale irrigation technologies (solar MajiPump and drip system) have a higher potential to increase production and income from irrigated crops and improve their nutrition if part of the income generated is used to purchase supplemental food for their nutrition.
6 Assefa, T. T.; Atampugre, Gerald; Tilahun, Seifu; Cofie, Olufunke. 2023. Modeling of water availability for food system transformation in Upper Offin Sub-basin and Mankran Micro-watershed of Ghana: a baseline study. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Initiative on West and Central African Food Systems Transformation. 35p.
Water availability ; Modelling ; Food systems ; Transformation ; Climate change ; Water balance ; Watersheds / Ghana / Upper Offin Sub-basin / Mankran Micro-Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H052655)
(864 KB)
The increasing population and changes in the climate in Africa demand a more sustainable approach to water usage for improved food and water security in the region. One of the key users of water, agriculture serves as the primary livelihood in Ghana, with a growing focus on cocoa production. To effectively implement sustainable water management strategies, it becomes imperative to conduct hydrological studies, including water balance components and water quality at sub-national and watershed scales. This would assist decision-makers in the proper planning and interventions for agriculture. This study aims to quantify and evaluate the hydrological response of the Upper Offin sub-basin and Mankran micro-watershed under baseline conditions. Upper Offin was selected because of its competing land uses of cocoa and mining, and Mankran was targeted as the CGIAR regional integrated initiative for Transforming Agrifood Systems in West and Sectral Africa (TAFS-WCA) is co-designing a landscape management plan for the area. The Soil and Water Assessment Tool (SWAT) model was first calibrated and validated at the Adimbera gauging station (Upper Offin sub-basin) using observed streamflow data from 2001 to 2011, considering Mankran as one of the SWAT sub-basins. After several iterations of the selected seven parametersthat include mainly channel and groundwater flow, the SWAT model reproduced the observed flow with reasonable performance. The sensitivity analysis depicted that channel and groundwater parameters were markedly the most sensitive in the region. Evapotranspiration accounts for the largest share of the water cycle, with a mean annual rainfall of 72% and 74% for the Upper Offin and Mankran watersheds, respectively. The mean annual surface runoff and percolation were below 5% for both watersheds. Also, the mean annual percolation for Upper Offin and Mankran were 15% and 17% of the rainfall and the mean annual sediment yield was 0.68 t/ha and 0.37 t/ha, respectively. The SWAT model successfully captured the hydrological responses in the study areas, providing a reliable quantification of surface runoff, percolation, and sediment yield under baseline conditions. Utilizing SWAT in this context was essential for assessing the potential impact of future supplementary irrigation interventions, evaluating the effectiveness of water management strategies, and monitoring changes in hydrological processes over both spatial and temporal scales.
7 Assefa, T. T.; Atampugre, Gerald; Tilahun, Seifu; Cofie, Olufunke. 2023. Modeling of water availability for food system transformation in Upper Offin Sub-basin and Mankran Micro-watershed of Ghana: scenarios analysis. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Initiative on West and Central African Food Systems Transformation. 25p.
Water availability ; Modelling ; Food systems ; Transformation ; Watersheds / Ghana / Upper Offin Sub-Basin / Mankran Micro-Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H052659)
(641 KB)
Agriculture remains the primary livelihood in Ghana, marked by a growing emphasis on cocoa production nationwide. Existing research highlights the importance of supplementing rainfed cocoa production with irrigation. Simultaneously, mining has emerged as a key driver of the country's economic growth. However, there is an urgent need to assess the measurable impacts of cocoa production with supplemental irrigation and mining on water resources sustainability and quality. This study aims to investigate how the supplementary irrigation of coca and mining affects the water balance components and water quality, with a focus on sediment yield in Ghana. It builds upon a baseline study in the Upper Offin sub-basin and an upland watershed of the Mankran microwatershed using the Soil and Water Assessment Tool (SWAT) model. The analysis indicates that applying supplemental irrigation to 15% of the cocoa area from shallow groundwater would not significantly affect basin water yields. However, the impacts of supplemental irrigation on 5% of the cocoa area from shallow groundwater would significantly affect the groundwater flow in the Upper Offin sub-basin. Conversely, expanding supplemental irrigation to 38% of the cocoa area (with landscape slope less than 8%) and encompassing the entire cocoa area in the Mankran microwatershed significantly influences hydrology. In the Mankran micro-watershed, supplemental irrigation to all cocoa farms increased evapotranspiration, percolation, and sub-surface flow by up to 9%, 28%, and 21.5%, respectively. In contrast, catchment water yield has been decreased by 19% and groundwater flow ceased due to supplemental irrigation. On the other hand, mining in the Upper Offin watershed (covering 5% of the area) and the Mankran micro-watershed (covering 6% of the area) significantly impacted hydrology and sediment yield. Surface runoff, catchment water yield, and sediment yield increased, respectively by 28%, 7%, and 80% for the Upper Offin watershed. Similarly, the Mankran micro-watershed showed a significant increase in surface runoff, water yield, and sediment yield by 34%, 8%, and 147% due to mining. Percolation and groundwater flow significantly decreased in both the Upper Offin and Mankran micro-watershed. The findings indicate that expanding mining poses a challenge to cocoa production from shallow groundwater. Mining areas must identify suitable areas to minimiz adverse effects on irrigated cocoa production and implementation land reclamation on mined areas. Further research is required to refine the representation of mining activities in the SWAT model for more accurate results on the location and spatial coverage of mining impacts. The study underscores the necessity of context-specific management strategies, considering both agricultural and mining activities in water resource management plans for long-term environmental health and socio-economic viability.
8 Hussein, M. A.; Riga, F. T.; Derseh, M. B.; Assefa, T. T.; Worqlul, A. W.; Haileslassie, Amare; Adie, A.; Jones, C. S.; Tilahun, Seifu A. 2024. Application of irrigation management and water-lifting technologies to enhance fodder productivity in smallholder farming communities: a case study in Robit Bata, Ethiopia. Agronomy, 14(5):1064. [doi: https://doi.org/10.3390/agronomy14051064]
Irrigation management ; Water productivity ; Irrigation technology ; Smallholders ; Farmers ; Irrigation water ; Fodder ; Pennisetum purpureum ; Watersheds ; Labour productivity ; Dry matter ; Soil water content ; Livestock ; Case studies / Ethiopia / Robit Bata / Yinebo Watershed / Robit Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H052854)
https://www.mdpi.com/2073-4395/14/5/1064/pdf?version=1715935300
https://vlibrary.iwmi.org/pdf/H052854.pdf
https://vlibrary.iwmi.org/pdf/H052854.pdf
(2.91 MB) (2.90 MB)
Small-scale cultivation of irrigated fodder is emerging as a vital production system in mixed farming communities. Efficient water management plays a key role in enhancing forage production, especially in the face of changing climate. A field-scale experimental study was conducted in Robit Bata kebele, Ethiopia, with the following objectives: (1) to examine the effects of conventional farmers’ irrigation scheduling versus climate-based irrigation scheduling; and (2) to assess the influence of water-lifting technologies (manual pulley and solar Majipump) on dry matter yield (DMY), water productivity (WP), irrigation labor productivity (ILP), and water productivity in terms of crude protein and metabolizable energy (WP.CP and WP.ME) of Napier grass. The experiment used 10 farmers’ plots each with a size of 100 m2 . Half of the plots were treated using farmers’ scheduling while the other half were treated using climate-based irrigation scheduling. Monitoring of irrigation water use and crop yield took place over two irrigation seasons from November 2020 to June 2021. Results showed there was an interaction effect of irrigation management (p = 0.019) and water-lifting technologies (p = 0.016) with season on DMY. The highest DMY occurred in the first irrigation season with climate-based scheduling and solar Majipump use. The interaction effect of irrigation management and season affected WP (p = 0.047). Climate-based scheduling had a higher WP in the first season, while farmers’ scheduling had a higher WP during the second season. On average, the solar Majipump outperformed the pulley, achieving 5 kg m-3 WP compared to the pulley’s 4 kg m-3 (p = 0.018). Emphasizing the seasonal impact, it is recommended to promote full irrigation (climate-based) in the first season for maximum yield and WP. Conversely, in the second season, advocating only deficit irrigation is advised due to water scarcity and sustainability concerns. Statistical parity in DMY and lower WP with full irrigation in the second season supports this recommendation, addressing the challenge of optimizing water use in the context of a changing climate and ensuring sustainable smallholder agriculture practices. Therefore, implementing appropriate irrigation management alongside efficient water-lifting technologies holds the potential to enhance fodder productivity and bolster smallholder farmers’ livelihoods. Future research should explore the comparative benefits of irrigated fodder versus other crops and the overall advantages of investing in irrigated fodder over vegetables.
9 Hussein, M. A.; Haileslassie, Amare; Derseh, M. B.; Assefa, T. T.; Riga, F. T.; Adie, A.; Tebeje, A. K.; Jones, C. S.; Tilahun, Seifu A. 2024. Enhancing irrigated forage crop production through water and nutrient management in the Ethiopian sub-humid highlands. Frontiers in Sustainable Food Systems, 8:1373698. [doi: https://doi.org/10.3389/fsufs.2024.1373698]
Forage ; Crop production ; Deficit irrigation ; Water management ; Nutrient management ; Water-use efficiency ; Water productivity ; Fertilizer application ; Yields ; Livestock ; Highlands / Ethiopia / Robit Bata
(Location: IWMI HQ Call no: e-copy only Record No: H052855)
https://www.frontiersin.org/articles/10.3389/fsufs.2024.1373698/pdf?isPublishedV2=False
https://vlibrary.iwmi.org/pdf/H052855.pdf
https://vlibrary.iwmi.org/pdf/H052855.pdf
(5.69 MB) (5.69 MB)
Introduction: The increasing pressure on land and water resources, fueled by high population growth and climate change, has profound implications for crop yield and quality. While studies thrive for various crops, a notable research gap exists in understanding the responses of forage crops to irrigation and nutrient management in developing countries. This study aims to address this gap by assessing the impact of irrigation and fertilizer application on forage production in the Ethiopian sub-humid highlands.
Methods: The experiment focused on four forage varieties, namely Napier grass (Cenchrus purpureus) cultivars, ILRI-16791, ILRI-16819, ILRI-16803, and Guinea grass (Megathyrsus maximus) ILRI-144 cultivated in experimental plots. Three irrigation levels designated as IR60 (60% of total available soil water), IR80 (80%), and IR100 (100%) were applied, along with three fertilizer rates: organic manure at 30 t ha-1 , and Urea-N at 100 kg ha-1 and 300 kg ha-1 . Agronomic data including growth performance, forage dry matter yield, and nutritional quality were collected during two trial years.
Results and discussion: Among the various irrigation treatments, IR80 demonstrated the most favorable balance between forage yield, WUE, net benefit, and LWP. In addition, the highest DMY, WUE, net benefit, and LWP were obtained for UREA at the rate of 300 kg ha-1 while the lowest DMY and WUE were observed for UREA at the rate of 100 kg ha-1 . Significant variations were observed among the four forage varieties, with Napier grass ILRI-16791 having the highest DMY (9.8 tons ha-1 ), WUE (39 kg ha-1 mm-1 ), LWP (0.28 USD m-3 for local cows, and 1.04 USD m-3 for crossbred cows), and net benefit (783 USD ha-1 ). For all forages combined, a 40 and 20% decrease in irrigation increased water use efficiency by 17 and 9.4%, respectively. These results indicate that a moderate level of deficient irrigation such as IR80 could be a viable water management strategy for irrigated forage, especially in water-scarce areas. The conserved water saved from the deficit irrigation can thus be used to irrigate additional land, contributing to a more sustainable and efficient water usage approach.
Methods: The experiment focused on four forage varieties, namely Napier grass (Cenchrus purpureus) cultivars, ILRI-16791, ILRI-16819, ILRI-16803, and Guinea grass (Megathyrsus maximus) ILRI-144 cultivated in experimental plots. Three irrigation levels designated as IR60 (60% of total available soil water), IR80 (80%), and IR100 (100%) were applied, along with three fertilizer rates: organic manure at 30 t ha-1 , and Urea-N at 100 kg ha-1 and 300 kg ha-1 . Agronomic data including growth performance, forage dry matter yield, and nutritional quality were collected during two trial years.
Results and discussion: Among the various irrigation treatments, IR80 demonstrated the most favorable balance between forage yield, WUE, net benefit, and LWP. In addition, the highest DMY, WUE, net benefit, and LWP were obtained for UREA at the rate of 300 kg ha-1 while the lowest DMY and WUE were observed for UREA at the rate of 100 kg ha-1 . Significant variations were observed among the four forage varieties, with Napier grass ILRI-16791 having the highest DMY (9.8 tons ha-1 ), WUE (39 kg ha-1 mm-1 ), LWP (0.28 USD m-3 for local cows, and 1.04 USD m-3 for crossbred cows), and net benefit (783 USD ha-1 ). For all forages combined, a 40 and 20% decrease in irrigation increased water use efficiency by 17 and 9.4%, respectively. These results indicate that a moderate level of deficient irrigation such as IR80 could be a viable water management strategy for irrigated forage, especially in water-scarce areas. The conserved water saved from the deficit irrigation can thus be used to irrigate additional land, contributing to a more sustainable and efficient water usage approach.
Powered by DB/Text WebPublisher, from
