Water resources in sub-Saharan Africa are more overstressed than in many other regions of the world. Experiments on commercial farms have shown that conservation agriculture (CA) can save water and improve the soil. Nevertheless, its benefits on smallholder irrigated farms have not been adequately investigated, particularly in dry monsoon phase in the Ethiopian highlands. We investigated the effect of conservation agriculture (grass mulch cover and no-tillage) on water-saving on smallholder farms in the Ethiopian highlands. Irrigated onion and garlic were grown on local farms. Two main factors were considered: the first factor was conservation agriculture versus conventional tillage, and the second factor was irrigation scheduling using reference evapotranspiration (ETo) versus irrigation scheduling managed by farmers. Results showed that for both onion and garlic, the yield and irrigation water use efficiency (IWUE) was over 40% greater for CA than conventional tillage (CT). The soil moisture after irrigation was higher in CA compared with CT treatment while CA used 49 mm less irrigation water. In addition, we found that ETo-based irrigation was superior to the farmers’ irrigation practices for both crops. IWUE was lower in farmers irrigation practices due to lower onion and garlic yield responses to overirrigation and greater water application variability.

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 (α = 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.

Small-scale irrigation in Ethiopia is a key strategy to improve and sustain the food production system. Besides the use of surface water for irrigation, it is essential to unlock the groundwater potential. It is equally important to use soil management and water-saving systems to overcome the declining soil fertility and the temporal water scarcity in the region. In this study, the solar MajiPump was introduced to enable dry season crop production in Ethiopia using shallow groundwater sources. The capacity of the MajiPumps (MP400 and MP200) was tested for the discharge head and discharge using three types of solar panels (150 W and 200 W rigid, and 200 W flexible). Besides, drip irrigation and conservation agriculture (CA) farming systems were evaluated in terms of water productivity and crop yield in comparison to the farmers’ practice (overhead irrigation and tilled farming system). Results indicated that the maximum discharge head capacity of the MajiPumps was 18 m, 14 m, 10 m when using MP400 with 200 W rigid, MP400 with 200 W flexible, and MP200 with 150 W rigid solar panels, respectively. The corresponding MajiPump flow rates ranged from 7.8 L/min to 24.6 L/min, 3 L/min to 25 L/min, and 3.6 L/min to 22.2 L/min, respectively. Compared to farmer’s practice, water productivity was significantly improved under the CA farming and the drip irrigation systems for both irrigated vegetables (garlic, onion, cabbage, potato) and rainfed maize production. The water productivity of garlic, cabbage, potato, and maize was increased by 256%, 43%, 53%, and 9%, respectively, under CA as compared to conventional tillage (CT) even under overhead irrigation. Thus, farmers can obtain a significant water-saving benefit from CA regardless of water application systems. However, water and crop productivity could be further improved in the combined use of MajiPump with CA and drip irrigation (i.e., 38% and 33% water productivity and 43% and 36% crop productivity improvements were observed for potato and onion, respectively). Similarly, compared to CT, the use of CA significantly increased garlic, cabbage, potato, and maize yield by 170%, 42%, 43%, and 15%, respectively under the MajiPump water-lifting system. Overall, the solar-powered drip irrigation and CA farming system were found to be efficient to expand small-scale irrigation and improve productivity and livelihoods of smallholder farmers in Ethiopia.

Investment in irrigation development is an important strategy in reducing risks associated with rainfall variability and achieving food security. This study examines the link between small-scale irrigation and household income. It also presents inherent institutional challenges in water allocation and the unintended outcomes. It used cross-sectional data obtained using a sample of 150 respondents selected through multi-stage sampling techniques from Deder district in eastern Ethiopia in 2009/2010 cropping year. The data were analyzed using Heckman-two step econometric models. The probit estimation shows that sex of the household head, access to credit and extension services have significant positive effect whereas the financial constraints restrains participation in irrigation water utilization. The ordinary least square using household income as outcome variable reveals that credit access, livestock holdings and proportion of land allocated to irrigation have significant positive effect on household income. This indicates that the more land is allocated to irrigation the higher will be the income. Moreover, the study pointed out that local institutional failure was a more important challenge than hydrological factors in managing the irrigation system. This has a policy implication in terms of strengthening the institutional environment.

Background This study was conducted to evaluate the performance of two small-scale irrigation (SSI) schemes in the sub-humid Ethiopian highlands. Water application at the farm level was monitored using partial flume and the average flow velocity along the main canal was measured using the current meter. The infiltration measurement was conducted 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 60cm depth. Climatic and agronomic data were collected from the nearby meteorological station and woreda agricultural office, respectively. CROPWAT was used to determine the water requirement of crops. Results The result showed that the average conveyance efficiency for the lined main canal was 90% and 92% for Mugie and Fesas SSI, respectively. The conveyance efficiency for the unlined main canal was in the order of 86% and 87% for Mugie and Fesas SSI. On the other hand, the average application efficiency and overall efficiency were found to be 56% and 51%, respectively, with storage efficiency of 50% for Mugie irrigation scheme. Similarly, the overall, application and storage efficiencies were found 50%, 54%, and 56%, respectively, for Fesas irrigation scheme. The relative irrigation and water supplies were 1.23 and 3.17, respectively, for Mugie SSI, while the supplies were 0.94 and 2.45, respectively, for Fesas SSI. Conclusions Conveyance efficiency for both Mugie and Fesas schemes was found below standard (95%) and overall efficacy was low as well (~50%). Failure of operating gates in the main canal, overtopping of water from the main canal due to canal siltation, and leakage through the main canals were the main causes for poor performance. Improvement measures are needed for both Mugie and Fesas irrigation schemes and institutional support is vital to improve and maintain the failure of infrastructures for better performance.