Irrigation and agriculture development in Africa: Impact on water quality and ecosystem health in the Ethiopian highlands

Evaluating the effect of intensification on water quality: shallow groundwater, streams, lake water bodies & biomass in the Amhara region of Ethiopia

Scaling-up Conservation Agriculture Production System (CAPS) with Drip Irrigation by Integrating MCE Technique and the APEX Model

The conservation agriculture production system (CAPS) approach with drip irrigation has proven to have the potential to improve water management and food production in Ethiopia. A method of scaling-up crop yield under CAPS with drip irrigation is developed by integrating a biophysical model: APEX (agricultural policy environmental eXtender), and a Geographic Information System (GIS)-based multi-criteria evaluation (MCE) technique. Topography, land use, proximity to road networks, and population density were considered in identifying potentially irrigable land. Weather and soil texture data were used to delineate unique climate zones with similar soil properties for crop yield simulation using well-calibrated crop model parameters. Crops water demand for the cropping periods was used to determine groundwater potential for irrigation. The calibrated APEX crop model was then used to predict crop yield across the different climatic and soil zones. The MCE technique identified about 18.7 Mha of land (16.7% of the total landmass) as irrigable land in Ethiopia. Oromia has the highest irrigable land in the nation (35.4% of the irrigable land) when compared to other regional states. Groundwater could supply a significant amount of the irrigable land for dry season production under CAPS with drip irrigation for the various vegetables tested at the experimental sites with about 2.3 Mha, 3.5 Mha, 1.6 Mha, and 1.4 Mha of the irrigable land available to produce garlic, onion, cabbage, and tomato, respectively. When comparing regional states, Oromia had the highest groundwater potential (40.9% of total potential) followed by Amhara (20%) and Southern Nations, Nationalities, and Peoples (16%). CAPS with drip irrigation significantly increased groundwater potential for irrigation when compared to CTPS (conventional tillage production system) with traditional irrigation practice (i.e., 0.6 Mha under CTPS versus 2.2 Mha under CAPS on average). Similarly, CAPS with drip irrigation depicted significant improvement in crop productivity when compared to CTPS. APEX simulation of the average fresh vegetable yield on the irrigable land under CAPS with drip irrigation ranged from 1.8–2.8 t/ha, 1.4–2.2 t/ha, 5.5–15.7 t/ha, and 8.3–12.9 t/ha for garlic, onion, tomato, and cabbage, respectively. CAPS with drip irrigation technology could improve groundwater potential for irrigation up to five folds and intensify crop productivity by up to three to four folds across the nation

Experimental Evaluation of Conservation Agriculture with Drip Irrigation for Water Productivity in Sub-Saharan Africa

A field-scale experimental study was conducted in Sub-Saharan Africa (Ethiopia and Ghana) to examine the effects of conservation agriculture (CA) with drip irrigation system on water productivity in vegetable home gardens. CA here refers to minimum soil disturbance (no-till), year-round organic mulch cover, and diverse cropping in the rotation. A total of 28 farmers (13 farmers in Ethiopia and 15 farmers in Ghana) participated in this experiment. The experimental setup was a paired ‘t’ design on a 100 m2 plot; where half of the plot was assigned to CA and the other half to conventional tillage (CT), both under drip irrigation system. Irrigation water use and crop yield were monitored for three seasons in Ethiopia and one season in Ghana for vegetable production including garlic, onion, cabbage, tomato, and sweet potato. Irrigation water use was substantially lower under CA, 18% to 45.6%, with a substantial increase in crop yields, 9% to about two-fold, when compared with CT practice for the various vegetables. Crop yields and irrigation water uses were combined into one metric, water productivity, for the statistical analysis on the effect of CA with drip irrigation system. One-tailed paired ‘t’ test statistical analysis was used to examine if the mean water productivity in CA is higher than that of CT. Water productivity was found to be significantly improved (α = 0.05) under the CA practice; 100%, 120%, 222%, 33%, and 49% for garlic, onion, tomato, cabbage, and sweet potato respectively. This could be due to the improvement of soil quality and structure due to CA practice, adding nutrients to the soil and sticking soil particles together (increase soil aggregates). Irrigation water productivity for tomato under CA (5.17 kg m−3 in CA as compared to 1.61 kg m−3 in CT) is found to be highest when compared to water productivity for the other vegetables. The mulch cover provided protection for the tomatoes from direct contact with the soil and minimized the chances of soil-borne diseases. Adapting to CA practices with drip irrigation in vegetable home gardens is, therefore, a feasible strategy to improve water use efficiency, and to intensify crop yield, which directly contributes towards the sustainability of livelihoods of smallholder farmers in the region

Impact of small-scale irrigation schemes on household income and the likelihood of poverty in the Lake Tana basin of Ethiopia

This study uses Tobit and Logit models to examine the impacts of selected small-scale irrigation schemes in the Lake Tana basin of Ethiopia on household income and the likelihood of poverty, respectively. Data for these analyses were collected from a sample of 180 households. Households using any of the four irrigation systems had statistically significantly higher mean total gross household income than households not using irrigation. The marginal impact of small-scale irrigation on gross household income indicated that each small scale-irrigation user increased mean annual household income by ETB 3353 per year, a 27% increase over income for non-irrigating households. A Logit regression model indicated that access to irrigation significantly reduced the odds that a household would be in the lowest quartile of household income, the poverty threshold used in this study. Households using concrete canal river diversion had higher mean cropping income per household than those using other irrigation types. Key challenges to further enhancing the benefits of irrigation in the region include water seepage, equity of water distribution, availability of irrigation equipment, marketing of irrigated crops and crop diseases facilitated by irrigation practices

Using Computer Models to Design Gully Erosion Control Structures for Humid Northern Ethiopia

Mini-Symposium: Modeling Methodology for Agricultural Researc

Resilience of rural groundwater supplies during drought in Ethiopia

As a result of climate change, sub-Saharan Africa, is expected to experience more frequent and extreme droughts, contributing to greater water insecurity. Droughts affect the reliability, quantity and quality of water available, potentially undermining recent gains in drinking water access and making it difficult to extend services. Ethiopia, in particular, is highly vulnerable to drought. Since 1965, Ethiopia has experienced 15 severe droughts affecting more than 65 million people and causing serious economic damage. Most recently, in 2015 and 2016, Ethiopia suffered a harsh drought, linked to El Nino, which forced more than 10 million people to rely on emergency aid due to crop and water supply failures. During the 2015-16 drought significant effort was made to monitor and understand the performance and use of rural water points. Drawing on two recently published studies we demonstrate that with adequate monitoring and maintenance rural groundwater points can deliver a consistent and safe water supply during drought. The first study monitored a total of 5196 water points (hand-pumps, motorized boreholes, springs, open-sources) and the success of a maintenance programme, every week for 12 weeks in early 2016. Enumerators used questionnaires on mobile phones to gather quantitative and qualitative data from those responsible for water points. The second study involved monitoring 51 groundwater points (hand-pumps, springs, hand-dug wells) over an 18 month period. Water sources were equipped with water level loggers and water was tested monthly for Thermo-tolerant Coliforms (TTCs). All sources were put under considerable strain during drought. Most demand was placed on motorised boreholes in lowland areas. Increases in functionality for motorised boreholes, as a result of the maintenance programme, lagged behind those of hand-pumped boreholes. More complex technologies have longer downtimes due to a lack of appropriate and/or accessible maintenance skills. Real time-monitoring and effective information flow helped facilitate responsive and proactive maintenance of infrastructure, and ensured demand was spread across a larger infrastructure portfolio reducing pressure on individual sources during the drought. Water level monitoring showed that shallow boreholes equipped with handpumps recovered quickly from daily abstraction. Recovery rates of hand-dug-wells and springs was longer. All sources were contaminated during the rains marking drought cessation but boreholes were least affected. We conclude that prioritising access to groundwater via multiple improved sources and a portfolio of technologies, such as hand-pumped and motorised boreholes, supported by responsive and proactive maintenance, increases rural water supply resilience to drought and climate change

Co-designing inclusive landscape management plans to transform agrifood systems: a technical brief

Landscape in Sub-Saharan Africa faces increasing pressure from both anthropogenic activities and climate change. The agrifood system struggles to utilize the landscape's potential. Misconceptions in landscape management practices, such as neglecting socio-ecological and participatory concepts, hinder sustainable development. Socio-ecological landscape management, which integrates social and ecological systems and promotes collaboration among stakeholders, innovation, resilience to risks, resource sustainability, and community satisfaction, is gaining acceptance. This technical note is to describe adaptive, inclusive landscape management plans that are sensitive to both ecological and health metrics and could be incorporated into governmental frameworks. The design process is iterative with 6 steps, incorporating the perspectives of local stakeholders, governance bodies, researchers, and local experts. The pathway culminates in a comprehensive Inclusive Landscape Management Plan (ILMP) that is both actionable and reflective of community needs