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UAV-based multispectral vegetation indices for assessing the interactive effects of water and nitrogen in irrigated horticultural crops production under tropical sub-humid conditions: A case of African eggplant.
(Agricultural Water Management, 2022) Mwinuka, P. R.; Mourice, S. K.; Mbungu, W. B.; Mbilinyi, B. P.; Tumbo, S. D.; Schmitter, P.; Sokoine University of Agriculture, Department of Civil and Water Resources Engineering, Tanzania; Sokoine University of Agriculture, Department of Crop Science and Horticulture, Tanzania; Ministry of Agriculture, Tanzania; International Water Management Institute (IWMI), Sri Lanka
UAV-based multispectral vegetation indices are often used to assess crop performance and water consumptive use. However, their ability to assess the interaction between water, especially deficit irrigation, and nitrogen application rates in irrigated agriculture has been less explored. Understanding the effect of water-nitrogen interactions on vegetation indices could further support optimal water and N management. Therefore, this study used a split plot design with water being the main factor and N being the sub-factor. African eggplants were drip irrigated at 100% (I100), 80% (I80) or 60% (I60) of the crop water requirements and received 100% (F100), 75% (F75), 50% (F50) or 0% (F0) of the crop N requirements. Results showed that the transformed difference vegetation index (TDVI) was best in distinguishing differences in leaf moisture content (LMC) during the vegetative stage irrespective of the N treatment. The green normalized difference vegetation index (GNDVI) worked well to distinguish leaf N during vegetative and full vegetative stages. However, the detection of the interactive effect of water and N on crop performance required a combination of GNDVI, NDVI and OSAVI across both stages as each of these 3 VI showed an ability to detect some but not all treatments. The fact that a certain amount of irrigation water can optimize the efficiency of N uptake by the plant is an important criterion to consider in developing crop specific VI based decision trees for crop performance assessments and yield prediction.
Phosphorus Export from Two Contrasting Rural Watersheds in the (Sub) Humid Ethiopian Highlands.
(Frontiers in Earth Science, 2021) Sishu1, F. K.; Bekele, A. M.; Schmitter, P.; Tilahun, S. A.; Steenhuis, T. S.; Faculty of Civil and Water Resources Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; International Water Management Institute, Yangon, Myanmar; Departments of Biological and Environmental Engineering, Cornell University, Ithaca, NY, United States
Establishing worldwide sustainable and phosphorus efficient cropping systems is urgently needed because the supply of suitable phosphate rock is limited, and excess phosphorus in streams causes eutrophication. One of the impediments in the developing world for sustainable P practices is the lack of studies on P transport and its eventual disposition in the environment. One of these regions with few studies is the Ethiopian Highlands, with permeable volcanic soils. The objective was to establish baseline data on P watershed export in the (sub)humid highlands. Two contrasting watersheds were selected near Lake Tana. For 2 years, stream discharge and sediment, total P, dissolved P, and bioavailable particulate P concentrations were determined at the watershed outlet. The first watershed is the 57 km2 Dangishta, with lava intrusion dikes, forcing subsurface flow through faults to the surface and preventing gully formation. Subsurface flow was half of the 1745 mm annual precipitation, and surface runoff and erosion were minimal. The second watershed is the 9 km2 Robit Bata with 1,420 mm precipitation. The banks of several river banks were slumping. The upper part of the watershed generates saturation excess runoff. A hillslope aquifer in the lower part provided interflow. The average sediment concentrations of 10.5 g L−1 in the stream in Robit Bata (11 times that in Dangishta) reflected the sediments from banks slipping in the stream. The hydrology and the soil loss directly affected the phosphorus export. In Dangishta, the total P concentration averaged 0.5 mg L−1 at the outlet. In Robit Bata, the average total P concentration was 2 mg L−1. The bioavailable particulate P concentration was only twice the concentration in the runoff water. The low phosphorus content of the subsoil slipping in Robit Bata moderated biologically available particulate P at the outlet. Average dissolved P concentrations for both watersheds were around 0.1 mg L−1 in the low range found in temperate climates. It reflects the difference in length of time that phosphorus fertilizers have been applied. Our research concludes that commonly implemented practices such as strengthening river banks and stabilizing gully might not lead to improved water quality in Lake Tana.
Mapping development potential of dry-season small-scale irrigation in Sub-Saharan African countries under joint biophysical and economic constraints - An agent-based modeling approach with an application to Ethiopia
(Agricultural Systems, 2021) Xie, H.; You, L.; Dile, Y. T.; Worqlul, A. W.; Bizimana, J.-C.; Srinivasan, R.; Richardson, J. W.; Gerik, T.; Clarke, N. P.; Environment and Production Technology Division, International Food Policy Research Institute, Washington, DC, United States of America; Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, United States of America; Texas AgriLife Research, Temple, TX, United States of America; Department of Agricultural Economics, Texas A&M University, College Station, TX, United States of America; The Norman Borlaug Institute for International Agriculture, College Station, TX, United States of America
Sub-Saharan Africa has long been beset with food insecurity. Investment in small-scale irrigation may provide a solution to address the challenge by extending crop production into the dry season. We present an agent-based modeling system to assess the potential of dry-season small-irrigation development in Sub-Saharan Africa with an application to Ethiopia. We identify significant potential for investing in dry-season small-scale irrigation in Ethiopia and map geographic domains with highest investment opportunities.
Seasonal variation in maternal dietary diversity is reduced by small-scale irrigation practices: a longitudinal study
(Maternal & Child Nutrition, 2021) Baye, K.; Mekonnen, D.; Choufani, J.; Yimam, S.; Bryan, E.; Grifith, J. K.; Ringler, C.; Center for Food Science and Nutrition, AddisAbaba University, Addis Ababa, Ethiopia; Environment and Production TechnologyDivision of the International Food PolicyResearch Institute, Addis Ababa, Ethiopia; Environment and Production TechnologyDivision of the International Food PolicyResearch Institute, Washington,District of Columbia, USA; Public Health and Community Medicine,Tufts University School of Medicine, TuftsUniversity, Boston, Massachusetts, USA
Some agricultural practices, such as irrigation, have the potential to buffer seasonal dietary gaps and through increased production and consumption improve diets, particularly of the rural poor relying on subsistence farming but also for rural and urban households purchasing irrigated produce on local markets. The study aimed to evaluate the effect of seasonality and irrigation on women's diet in rural Ethiopia. Using a longitudinal study design, three rounds of surveys were conducted among women of reproductive age (15–49 years). Data on socioeconomic status, food consumption and haemoglobin concentration was collected. Energy and nutrient intakes were estimated using an interviewer-administered multiple-pass 24-h recall. Women's dietary diversity score (WDDS), the proportion of women meeting the minimum dietary diversity for women (MDDW), haemoglobin concentration, the prevalence of anaemia and energy and nutrients intakes were compared between irrigators and nonirrigators and by season. Associations between MDDW/WDDS and irrigation status were assessed using fixed-effect models, after adjusting for covariates. WDDS was low (3–4 out of 10 food groups) and exhibited high seasonal variability (p < 0.05). Diets were predominantly cereal-based, with little consumption of nutrient-dense foods like fruits and animal source foods. High seasonal variability in energy, protein, vitamin C, calcium, iron and zinc intakes were observed (p < 0.01). Irrigators were more likely to meet the MDDW than women from non-irrigating households (p < 0.05). No cases of malaria were reported from the three rounds of screening. There is a high seasonal variation in women's diet, but this could be partly offset by irrigation practices.
Understanding the pathways to women’s empowerment in Northern Ghana and the relationship with small-scale irrigation
(Agriculture and Human Values, 2022) Bryan, E., Garner, E.; Environment and Production Technology Division, International Food Policy Research Institute, 1201 Eye St., NW, Washington, DC 20005, USA; Cornell University, Ithaca, NY 14850, USA
Women’s empowerment is often an important goal of development interventions. This paper explores local perceptions of empowerment in the Upper East Region of Ghana and the pathways through which small-scale irrigation intervention targeted to men and women farmers contributes to women’s empowerment. Using qualitative data collected with 144 farmers and traders through 28 individual interviews and 16 focus group discussions, this paper innovates a framework to integrate the linkages between small-scale irrigation and three dimensions of women’s empowerment: resources, agency, and achievements. The relationship between the components of empowerment and small-scale irrigation are placed within a larger context of social change underlying these relationships. This shows that many women face serious constraints to participating in and benefitting from small-scale irrigation, including difficulties accessing land and water and gender norms that limit women’s ability to control farm assets. Despite these constraints, many women do benefit from participating in irrigated farming activities leading to an increase in their agency and well-being achievements. For some women, these benefits are indirect—these women allocate their time to more preferred activities when the household gains access to modern irrigation technology. The result is a new approach to understanding women’s empowerment in relation to irrigation technology.
Solar or Diesel: A Comparison of Costs for Groundwater‐Fed Irrigation in Sub‐Saharan Africa Under Two Energy Solutions
(Earth’s Future, 2021) Xie, H.; Ringler, C.; Mondal, A. H.; Environment and Production Technology Division, International Food Policy Research Institute, Washington, DC, USA; Department of Electrical and Electronic Engineering, Daffodil International University, Dhanmondi, Dhaka, Bangladesh
Sub-Saharan Africa has long been beset with food insecurity and energy poverty. Expanding irrigated agriculture can help boost food production in the region, but this requires energy for accessing water, especially in groundwater-fed irrigation. This paper compared economic performance of groundwater pumping for irrigation under two energy solutions: solar photovoltaic (PV) and diesel fuel. We estimated the life-cycle costs of the power units of two pumping systems for a range of crop and irrigation method scenarios and mapped their relative cost-effectiveness over cropland in sub-Saharan Africa. As a renewable and clean energy source, solar energy has attracted much attention and there is keen interest in investing in solar PV to support the development of irrigated agriculture. Results of this study provide insights into the prospects of promoting solar irrigation in sub-Saharan Africa.
Conservation and Conventional Vegetable Cultivation Increase Soil Organic Matter and Nutrients in the Ethiopian Highlands
(Water, 2022) Belay, S. A.; Assefa, T. T.; Worqlul, A. W.; Steenhuis, T. S.; Schmitter, P.; Reyes, M. R.; Vara Prasad, P. V.; Tilahun, S. A.; Faculty of Civil and Water Resources Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; Blackland Research Center, Texas A&M AgriLife Research, Temple, TX 76502, USA; Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA; International Water Management Institute, Yangon 11081, Myanmar; Sustainable Intensification Innovation Laboratory, Department of Agronomy, Kansas State University, Manhattan, Kansas, KS 66506, USA
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.
Identification of suitable areas for fodder production in Ethiopia.
(CATENA, 2022) Worqlul, A.W.; Dile, Y. T.; Bezabih, M.; Aberra, A.; Srinivasan, R.; Lefore, N.; Clarke, N.; Blackland Research Center, Texas AgriLife Research, Temple, TX, USA; Spatial Sciences Laboratory, Texas A&M University, College Station, TX, USA; International Livestock Research Institute, Addis Ababa, Ethiopia; The Norman Borlaug Institute for International Agriculture, Texas A&M AgriLife Research, College Station, TX, USA
Despite Ethiopia’s significant livestock population, the largest in Africa, productivity is constrained by the seasonality of feed quality and quantity. Developing improved fodder production systems can contribute to poverty reduction goals and thereby enhance social-ecological resilience through building risk buffering assets. Therefore, this study focuses on evaluating the suitability of lands for selected fodder crops in Ethiopia applying GIS-based Multi-Criteria Evaluation (MCE) techniques and accessing the irrigation potential of the shallow groundwater. Groundwater data collected from the British Geological Survey (BGS) was used to assess the groundwater irrigation potential. The fodder crops selected were Napier (Pennisetum purpureum), alfalfa (Medicago sativa), oats (Avena sativa), vetch (Vicia sativa), and desho (Pennisetum pedicellatum). The key factors that significantly affect land suitability for fodder production evaluated include climate (rainfall and evapotranspiration), physical land features (land use, soil, and slope), and market access (livestock population and proximity to roads). The factors were weighted with a pairwise comparison matrix followed by reclassification and overlaying to identify suitable areas for irrigated fodder production. The results indicated that ∼ 31% of the country (∼350,500 km2) is highly suitable for producing desho, followed by vetch (23%), Napier (20%), Alfalfa (13%), and Oats (12%). The basin level analysis indicated that the Abbay river basin has the largest suitable area for Napier and Oats production while the Genale-Dawa River basin has the largest suitable area for alfalfa, vetch, and desho production. The analysis also indicated that the suitable area has access to groundwater that could be accessed with simple water-lifting technologies (≤30 m from the surface). This study provides useful insights for decision-makers, practitioners, and the private sector to prioritize and scale fodder production in Ethiopia.
Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia
(Agricultural Water Management, 2021) Worqlul, A. W.; Dile, Y. T.; Schmitter, P.; Bezabih, M.; Adie, A.; Bizimana, J.-C.; Srinivasan, R.; Lefore, N.; Clarke, N.; Blackland Research Center, Texas AgriLife Research, Temple, TX, USA; Spatial Sciences Laboratory, Texas A&M University, College Station, TX, USA; International Water Management Institute C/o Irrigation Head Office, Yangon, Myanmar; International Livestock Research Institute, Addis Ababa, Ethiopia; Department of Agricultural Economics, Texas A&M University, College Station, TX, USA; The Norman Borlaug Institute for International Agriculture, Texas A&M AgriLife Research, College Station, TX, USA
Livestock is an integral part of the agricultural system in sub-Saharan Africa, serving as a food source, income, fertilizer, and power for farming and transportation. However, the productivity of the livestock system has been hampered due to a lack of sufficient quantity and quality feed. This study evaluates the gaps and constraints of fodder and nutritional potential for livestock feed using small-scale irrigation (SSI). The study comprised of 30 randomly selected farmers from two different ecological zones in Ethiopia. Half of the farmers cultivated Napier grass (Pennisetum purpureum) in the Robit watershed in northern Ethiopia, and the other half cultivated mixed vetch (Lathyrus cicera) and oats (Avena sativa) in Lemo watershed in southern Ethiopia. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) were applied in an integrated manner to assess the impacts of SSI at the watershed and field-scale levels, respectively. The watershed-scale analysis showed that there is a substantial amount of surface runoff and shallow groundwater recharge that could be used for dry season fodder production using irrigation. Field data calibrated APEX model indicated that Napier yield could be maximized with 550 mm of water in Robit watershed. While in the Lemo watershed, maximum vetch and oats yield may be achieved with 250 mm of water. The major constraints for Napier and oats production in the study sites were soil fertility, especially nitrogen and phosphorus, and vetch production was limited by high temperature. Fodder samples were collected at the time of harvest to evaluate feed quality. The nutritional analysis indicated that Napier grass has a higher dry matter and ash (mineral) content compared to oats and vetch. However, vetch has higher crude protein content (18%) compared to Napier (10%) and oats (6%). Overall the study indicated that cultivating vetch provided superior performance in terms of providing quality feed and environmental services.
Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia
(Agricultural Water Management, 2021) Worqlul, W. A.; Dile, T. Y.; Schmitter, P.; Bezabih, M.; Adie, A.; Bizimana, J-C; Srinivasan, R.; Lefore, N.; Clarke, N.; Blackland Research Center, Texas AgriLife Research, Temple, TX, USA; Spatial Sciences Laboratory, Texas A&M University, College Station, TX, USA; International Water Management Institute C/o Irrigation Head Office, Yangon, Myanmar; International Livestock Research Institute, Addis Ababa, Ethiopia; Department of Agricultural Economics, Texas A&M University, College Station, TX, USA; The Norman Borlaug Institute for International Agriculture, Texas A&M AgriLife Research, College Station, TX, USA
Livestock is an integral part of the agricultural system in sub-Saharan Africa, serving as a food source, income, fertilizer, and power for farming and transportation. However, the productivity of the livestock system has been hampered due to a lack of sufficient quantity and quality feed. This study evaluates the gaps and constraints of fodder and nutritional potential for livestock feed using small-scale irrigation (SSI). The study comprised of 30 randomly selected farmers from two different ecological zones in Ethiopia. Half of the farmers cultivated Napier grass (Pennisetum purpureum) in the Robit watershed in northern Ethiopia, and the other half cultivated mixed vetch (Lathyrus cicera) and oats (Avena sativa) in Lemo watershed in southern Ethiopia. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) were applied in an integrated manner to assess the impacts of SSI at the watershed and field-scale levels, respectively. The watershed-scale analysis showed that there is a substantial amount of surface runoff and shallow groundwater recharge that could be used for dry season fodder production using irrigation. Field data calibrated APEX model indicated that Napier yield could be maximized with 550 mm of water in Robit watershed. While in the Lemo watershed, maximum vetch and oats yield may be achieved with 250 mm of water. The major constraints for Napier and oats production in the study sites were soil fertility, especially nitrogen and phosphorus, and vetch production was limited by high temperature. Fodder samples were collected at the time of harvest to evaluate feed quality. The nutritional analysis indicated that Napier grass has a higher dry matter and ash (mineral) content compared to oats and vetch. However, vetch has higher crude protein content (18%) compared to Napier (10%) and oats (6%). Overall the study indicated that cultivating vetch provided superior performance in terms of providing quality feed and environmental services.
The impact of rainfall distribution methods on streamflow throughout multiple elevations in the Rocky Mountains using the APEX model—Price River watershed, Utah
(Journal of Environmental Quality, 2021) Worqlul, A. W.; Jeong, J.; Green, C. H. M.; Abitew, T. A.; Blackland Research Center, Texas A&MAgriLife Research, Temple, TX 76502,USA; United States Department of the Interior,Bureau of Land Management, NationalOperations Center, Denver Federal Center,Denver, CO 80215, USA
The hydrology of mountainous watersheds in the western United States is significantly influenced by snow year-round. It is widely known that topography affects precipitation; however, the knowledge of how watershed rainfall designation methods affect streamflow is not well understood for high-relief areas. The objectives of this study were to assess the predictive capability of the Agricultural Policy/Environmental eXtender (APEX) model to simulate streamflow in a snowmelt-dominated watershed with high spatial rainfall variability through (a) allocating weather stations to sub-basins based on a conventional Thiessen polygon method (CM) or a rainfall-elevation–based input (RE) and using an areal average Parameter-Elevation Regression on Independent Slopes Model (PRISM) rainfall designation and (b) improving the snowmelt processes in the Price River watershed, Utah. The updated APEX model with snowmelt parameters significantly improved spring flood simulation. The RE was the most robust method in snowmelt and seasonal streamflow simulations compared with the CM and PRISM rainfall designations. Adapting the APEX model to simulate snow-dominant complex terrains will provide crucial water quantity and quality predictions for reliable environmental and watershed management assessment.
Who is Likely to Benefit from Public and Private Sector Investments in Farmer-led Irrigation Development? Evidence from Ethiopia
(The Journal of Development Studies, 2021) Kafle, K.; Omotilewa, O.; Leh, M.; Schmitter, P.; International Water Management Institute (IWMI), Pelawatte, Sri Lanka; African Development Bank (AfDB), Abidjan, Cote d’Ivoire; Water Global Practice, World Bank, Washington, DC, USA
In recent years, farmer-led irrigation development has gained the interest of development partners and governments in the Global South following its success in enhancing agricultural production and livelihoods in South Asia. However, little is known about the socio-economic situation of farmers who receive public support for its expansion. Considering its rapid expansion in sub-Saharan Africa, we take the case of Ethiopia and explore the relationship between irrigation suitability and farmers’ socio-economic status. We find that high-value crop producers and wealthier farmers are most likely to make private investments and also benefit from public support in farmer-led irrigation expansion if investments are directed to land areas highly suitable for irrigation. Cultivation of high-value crops (fruit, vegetables) was common in areas more suitable for irrigation but staple crop cultivation (cereals, legumes) was negatively associated with irrigation suitability. Wealth status (consumption expenditure, asset index, and land size) was also positively correlated with irrigation suitability. A 10 per cent increase in groundwater irrigation suitability score was associated with a 2 per cent increase in per-capita consumption expenditure. Results imply that policies aiming to facilitate farmer-led irrigation development should combine biophysical information on land and water suitability for irrigation with household socio-economic characteristics and existing agricultural systems.
The effect of nitrogen-fertilizer and optimal plant population on the profitability of maize plots in the Wami River sub-basin, Tanzania: A bio-economic simulation approach
(Agricultural Systems, 2020) Kadigia, I. L.; Richardson, J. W.; Mutabazi, K. D.; Philip, D.; Mourice, S. K.; Mbungu, W.; Bizimana, J.-C.; Sieber, S.; School of Agricultural Economics and Business Studies, Sokoine University of Agriculture, P.O. Box 3007, Morogoro, Tanzania; Soil-Water Management Research Programme, Sokoine University of Agriculture, P.O. Box 3003, Morogoro, Tanzania; Department of Agricultural Economics, Texas A&M University, 600 John Kimbrough Blvd/AGLS Blg, College Station, TX 77843-2124, USA; Department of Crop Science and Horticulture, Sokoine University of Agriculture, P.O. Box 3005, Morogoro, Tanzania; Department of Engineering Sciences and Technology, Sokoine University of Agriculture, P.O. Box 3003, Morogoro, Tanzania; Leibniz-Centre for Agriculturald Landscape Research, Eberswalder Straße 84, 15374 Müncheberg, Germany; Department of Agricultural Economics, Faculty of Life Sciences Thaer-Institute, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
Maize (Zea mays L.) is the essential staple in sub-Saharan Africa (SSA) and Tanzania in particular; the crop accounts for over 30% of the food production, 20% of the agricultural gross domestic product (GDP) and over 75% of the cereal consumption. Maize is grown under a higher risk of failure due to the over-dependence rain-fed farming system resulting in low income and food insecurity among maize-based farmers. However, many practices, including conservation agriculture, soil and water conservation, resilient crop varieties, and soil fertility management, are suggested to increase cereal productivity in Tanzania. Improving planting density, and the use of fertilizers are the immediate options recommended by Tanzania's government. In this paper, we evaluate the economic feasibility of the improved planting density (optimized plant population) and N-fertilizer crop management practices on maize net returns in semi-arid and sub-humid agro-ecological zones in the Wami River sub-Basin, Tanzania. We introduce a bio-economic simulation model using Monte Carlo simulation procedures to evaluate the economic viability of risky crop management practices so that the decision-maker can make better management decisions. The study utilizes maize yield data sets from two biophysical cropping system models, namely the APSIM and DSSAT. A total of 83 plots for the semi-arid and 85 plots for the sub-humid agro-ecological zones consisted of this analysis. The crop management practices under study comprise the application of 40 kg N-fertilizer/ha and plant population of 3.3 plants/m2. The study finds that the use of improved plant population had the lowest annual net return with fertilizer application fetching the highest return. The two crop models demonstrated a zero probability of negative net returns for farms using fertilizer rates of 40 kg N/ha except for DSSAT, which observed a small probability (0.4%) in the sub-humid area. The optimized plant population presented 16.4% to 26.6% probability of negatives net returns for semi-arid and 14.6% to 30.2% probability of negative net returns for sub-humid zones. The results suggest that the application of fertilizer practices reduces the risks associated with the mean returns, but increasing the plant population has a high probability of economic failure, particularly in the sub-humid zone. Maize sub-sector in Tanzania is projected to continue experiencing a significant decrease in yields and net returns, but there is a high chance that it will be better-off if proper alternatives are employed. Similar studies are needed to explore the potential of interventions highlighted in the ACRP for better decision-making.
Berken plow and intercropping with pigeon pea ameliorate degraded soils with a hardpan in the Ethiopian highlands
(Geoderma, 2021) Fenta, H. M.; Hussein, M. A.; Tilahun, S. A.; Nakawuka, P.; Steenhuis, T. S.; Barron, J.; Adie, A.; Blummel, M.; Schmitter, P.; Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Ethiopia; International Water Management Institute (IWMI), Addis Ababa, Ethiopia; Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA; International Water Management Institute, Colombo, Sri Lanka; International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
Closing the yield gap and enhancing efficiency in rainfed maize production systems in Ethiopia requires urgent action in increasing the productivity of degraded agricultural land. The degradation of land through continuous compaction and decline in the organic matter has resulted in a wide-spread formation of a hardpan that restricts deep percolation, prevents plant root development, and, ultimately can lead to increased erosion. Studies exploring practical low-cost solutions to break the hardpan are limited in Ethiopia. The main objective was to evaluate soil mechanical (i.e. modified plow or Berken plow) or biological intervention (i.e. intercropping with pigeon pea) effectiveness to enhance soil water management and crop yield of rainfed maize systems whilst reducing soil erosion and runoff. Five farm fields, each including four plots with different tillage treatments, were monitored during two rainy seasons in 2016 and 2017. The treatments were: (i) farmers practice under conventional (CT) tillage; plots tilled three times using an oxen driven local plow Maresha, (ii) no-till (NT), (iii) Berken tillage (BT), plots tilled three times using an oxen pulled Berken plow, and (iv) biological (CT + Bio), tap-rooted pigeon pea intercropped with maize on plots conventionally tilled. Results showed that mean tillage depth was significantly deeper in the BT (28 cm) treatment compared to CT and CT + Bio (18 cm) treatments. Measured soil penetration resistance significantly decreased up to 40 cm depth under BT and maize roots reached 1.5 times deeper compared to roots measured in the CT treatment. Under BT, the estimated water storage in the root zone was estimated at 556 mm, 1.86 times higher compared to CT, 3.11 times higher compared to NT and 0.89 times higher compared to CT + Bio. The positive effects on increased water storage and root development resulted in an average increase in maize grain (i.e. 15%, 0.95 t ha−1) and residual above ground biomass (0.3%, 6.4 t ha−1) leading to a positive net benefit of 138 USD ha−1 for the BT treatment compared to the CT treatment. The negative net benefit obtained under CT and CT+Bio was mainly related to the high labor cost related to plowing, weeding, planting, and fertilizer application whilst in the NT this was related to the significantly lower maize yields. The positive effects in the BT treatment, and to some extent the CT+Bio treatment show great potential for smallholder rainfed maize systems where degraded soils with hardpans and high variability in rainfall prevail.
Evaluating the Effectiveness of Best Management Practices On Soil Erosion Reduction Using the SWAT Model: for the Case of Gumara Watershed, Abbay (Upper Blue Nile) Basin
(Environmental Management, 2021) Gashaw, T.; Dile, Y. T.; Worqlul, A. W.; Bantider, A.; Zeleke, G.; Bewket, W.; Alamirew, T.; Department of Natural Resource Management, College of Agriculture and Environmental Science, Bahir Dar University, Bahir Dar, Ethiopia; College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, USA; Blackland Research and Extension Center, Texas A & M University, Temple, TX, USA; Water and Land Resource Center, Addis Ababa University, Addis Ababa, Ethiopia; College of Development Studies, Addis Ababa University, Addis Ababa, Ethiopia; Department of Geography and Environmental Studies, Addis Ababa University, Addis Ababa, Ethiopia; Ethiopiann Institute of Water Recources, Addis Ababa University, Addis Ababa, Ethiopia
This study was conducted to evaluate the effectiveness of best management practices (BMPs) to reduce soil erosion in Gumara watershed of the Abbay (Upper Blue Nile) Basin using the Soil and Water Assessment Tool (SWAT) model. The model was calibrated (1995–2002) and validated (2003–2007) using the SWAT-CUP based on observed streamflow and sediment yield data at the watershed outlet. The study evaluated four individual BMP Scenarios; namely, filter strips (FS), stone/soil bunds (SSB), grassed waterways (GW) and reforestation of croplands (RC), and three blended BMP Scenarios, which combines individual BMPS of FS and RC (FS & RC), GW and RC (GW & RC), and SSB and GW (SSB & GW). Mean annual sediment yield at the baseline conditions was estimated at 19.7 t ha−1yr−1, which was reduced by 13.7, 30.5, 16.2 and 25.9% in the FS, SSB, GW, and RC Scenarios, respectively at the watershed scale. The highest reduction efficiency of 34% was achieved through the implementations of the SSB & GW Scenario. The GW & RC, and FS & RC Scenarios reduced the baseline sediment yield by 32% and 29.9%, respectively. The study therefore concluded that the combined Scenarios mainly SSB & GW, and GW & RC can be applied to reduce the high soil erosion in the Gumera watershed, and similar agro-ecological watersheds in Ethiopia. In cases where applying the combined scenarios is not possible, the SSB Scenario can yield significant soil erosion reduction.
Household Food Security and Nutrition Analysis Using a Farm Simulation Model (FARMSIM): Case Study of Robit in Amhara Region, Ethiopia
(ES Food & Agroforestry, 2020) Bizimana, J.-C.; Richardson, J. W.; Clarke, N. P.; Agricultural & Food Policy Center, Department of Agricultural Economics, Texas A&M University, 600 John Kimbrough Blvd, College Station, TX 77843-2124.; Agricultural & Food Policy Center, Department of Agricultural Economics, Texas A&M University, 600 John Kimbrough Blvd, College Station, TX 77843; Vice Chancellor for Agriculture Office, Texas A&M University; 534 John Kimbrough Blvd., College Station, Texas 77843-2120
The majority of the world’s undernourished people are located in developing countries, including Sub-Saharan Africa. One way of combatting food insecurity is to increase food production and promote the consumption of balanced diets. This study evaluates the impact of small-scale irrigation technologies on food security and nutrition through food production and consumption in Robit village, Amhara region of Ethiopia. Household survey data and a farm level economic and nutrition simulation model (FARMSIM) is used to perform the analysis. A baseline scenario with minimal irrigation and current food consumption is compared to four alternative irrigation scenarios producing vegetables and fodder and aligned with four different food consumption patterns. Nutrition and food security evaluation is based on the intake per day and adult equivalent of calories, proteins, fat, iron, calcium and vitamin A. Food consumption in the baseline scenario indicates a satisfactory intake of calories from a cereal-based diet dominated by teff and maize but limited in consumption of fruits, vegetables, pulses and animal source foods. The alternative scenario under vegetables and fodder production shows the highest nutritional and economic outcomes allowing the household to purchase supplemental food items such as milk, meat, and eggs to meet nutritional needs.
Potential of Urochloa grass hybrids as fodder in the Ethiopian highlands
(Agronomy Journal, 2021) Worku, M.; Lemma, H.; Shawle, K.; Adie, A.; Duncan, A. J.; Jones, C. S.; Mekonnen, K.; Notenbaert, A.; Bezabih, M.; Wolaita Sodo Univ., P.O. Box 138, Sodo,Ethiopia; Mekedela Amba Univ., PO Box 999,Tuluawliya, Ethiopia; International Livestock Research Institute,P O Box 5689, Addis Ababa, Ethiopia; Univ. of Edinburgh, Edinburgh, UK; International Center for TropicalAgriculture, P. O. Box, Nairobi, Kenya",Urochloa grasses have shownpromising results for smallholders to cope with feed shortages in tropical Africa. The objective of this study was to evaluate the performance of two Urochloa hybrids
Mulato-I and Mulato-II
Improving Hydrologic Simulations of a Small Watershed through Soil Data Integration
(Water, 2020) Bayabil, H. K.; Dile, Y. T.; Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Ethiopia; International Water Management Institute (IWMI), Addis Ababa, Ethiopia; Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA; International Water Management Institute, Colombo, Sri Lanka; International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
The effects of soil data sources on the performance of hydrologic model simulations remain poorly understood compared to the effects of other data inputs. This paper investigated the effects of different soil datasets in simulating streamflow and sediment yield using the Soil and Water Assessment Tool (SWAT). Furthermore, potential improvements in watershed simulations were evaluated by integrating field measured soil parameters (user soil) with global soil datasets. Five soil datasets, namely user soil, AfSIS (Africa Soil Information Service), Food and Agriculture Organization (FAO), and two integrated soils (User-AfSIS and User-FAO) produced by assimilating the user soil with the latter two, were evaluated. The benefits of the user soil in improving streamflow simulations to better replicate observed flow were greater at daily time steps than monthly. Compared to the individual AfSIS and FAO soils, their integration with the user soil improved the daily Nash-Sutcliffe Efficiency (NSE) by 0.19 and 0.17 during model calibration, respectively. Overall, all soils performed relatively similar with monthly sediment yield simulations, which were improved when it was integrated with the user soil. Based on selected rainfall events, the watershed response time was less than 1 h, which suggests that the watershed has a quick runoff response time. This paper showed that streamflow and sediment yield simulation performances of freely available global soil datasets can be improved through integration with locally measured soil information. This study demonstrated that the availability of local soil information is critical for daily hydrologic model simulations, which is critical for planning effective soil and water management practices at plot and field scales.
APEX-MODFLOW: A New integrated model to simulate hydrological processes in watershed systems
(Environmental Modelling & Software, 2021) Bailey, R. T.; Tasdighi, A.; Park, S.; Tavakoli-Kivi, S.; Abitew, T.; Jeong, J.; Green, C. H. M.; Worqlul, A. W.; Department of Civil and Environmental Engineering, Colorado State University, USA; Blackland Extension and Research Center, Texas A&M AgriLife, USA; US Department of Interior, Bureau of Land Management, USA; INTERA Incorporated, 3838 W. Carson Street, #380, Torrance, CA, 90503, USA
APEX (Agricultural Policy/Environmental eXtender) is an oft-used agroecosystem model but has limited use in groundwater-driven watersheds due to a simplistic representation of groundwater processes. This paper presents the linkage of APEX and the groundwater flow model MODFLOW into a single modeling code. The mapping of recharge, groundwater head, and groundwater-surface water interactions are handled internally via subroutines. The APEX-MODFLOW model is applied to three watersheds in the United States for testing code accuracy and hydrologic state variables and fluxes: the Animas River Watershed, Colorado and New Mexico (3543 km2); the Price River Watershed, Utah (4886 km2); and the Middle Bosque River Watershed, Texas (470 km2). Whereas the hydrology of the Animas River and Price River watersheds is driven by snowmelt and spring runoff, the hydrology of the Middle Bosque River Watershed is driven by summer thunderstorms. The model can be used for scenario analysis in groundwater-driven watersheds.
Multi-Dimensional Drought Assessment in Abbay/Upper Blue Nile Basin: The Importance of Shared Management and Regional Coordination Efforts for Mitigation
(Remote Sensing, 2021) Bayissa, Y.; Moges, S.; Melesse, A.; Tadesse, T.; Abiy, A. Z.; Worqlul, A.; Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USA; Department of Earth and Environment, Florida International University, Miami, FL 33199, USA; Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA; National Drought Mitigation Center, University of Nebraska-Lincoln, Lincoln, CA 68583, USA; Blackland Research and Extension Center, Texas A&M Agrilife Research, Temple, TX 76502, USA
Drought is one of the least understood and complex natural hazards often characterized by a significant decrease in water availability for a prolonged period. It can be manifested in one or more forms as meteorological, agricultural, hydrological, and/or socio-economic drought. The overarching objective of this study is to demonstrate and characterize the different forms of droughts and to assess the multidimensional nature of drought in the Abbay/ Upper Blue Nile River (UBN) basin and its national and regional scale implications. In this study, multiple drought indices derived from in situ and earth observation-based hydro-climatic variables were used. The meteorological drought was characterized using the Standardized Precipitation Index (SPI) computed from the earth observation-based gridded CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) rainfall data. Agricultural and hydrological droughts were characterized by using the Soil Moisture Deficit Index (SMDI) and Standardized Runoff-discharge Index (SRI), respectively. The monthly time series of SMDI was derived from model-based gridded soil moisture and SRI from observed streamflow data from 1982 to 2019. The preliminary result illustrates the good performance of the drought indices in capturing the historic severe drought events (e.g., 1984 and 2002) and the spatial extents across the basin. The results further indicated that all forms of droughts (i.e., meteorological, agricultural, and hydrological) occurred concurrently in Abbay/Upper Blue Nile basin with a Pearson correlation coefficient ranges from 0.5 to 0.85 both Kiremt and annual aggregate periods. The concurrent nature of drought is leading to a multi-dimensional socio-economic crisis as indicated by rainfall, and soil moisture deficits, and drying of small streams. Multi-dimensional drought mitigation necessitates regional cooperation and watershed management to protect both the common water sources of the Abbay/Upper Blue Nile basin and the socio-economic activities of the society in the basin. This study also underlines the need for multi-scale drought monitoring and management practices in the basin.

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