Ex Ante Analysis of Small-Scale Irrigation Interventions in Dangila

The USAID Feed the Future Innovation Laboratory for Small-Scale Irrigation (ILSSI) conducted an ex ante analysis of proposed SSI interventions in Dangila woreda, Amhara region, Ethiopia. The analysis aimed to assess the effects of increased SSI on crop production, farm-family economics, and environmental services. The proposed SSI interventions focused on maximizing SSI of high-value, dry-season crops, using shallow groundwater and one of five alternative water-lifting technologies. ILSSI evaluated the proposed SSI interventions by simulating and comparing two alternative farming systems: a crop rotation of maize and teff grown in alternating wet seasons, applying fertilizer at rates currently used by farmers in the region; and a crop rotation consisting of wet-season grains (maize or teff), fertilized at government-recommended rates, plus an irrigated, dry-season double crop (onion) on all irrigable land. Simulations indicated that there is a large potential for increased SSI in Dangila. A complete hydrologic analysis of the area's 5150-ha watershed calculated that the average annual volumetric groundwater recharge was over 26 million m3, and simulations indicated that the proposed SSI interventions would use less than 20% of the annual shallow groundwater recharge. The proposed SSI interventions increased wet-season grain yields significantly, presumably because crop rotation operations implemented in conjunction with the proposed SSI scenarios resulted in improvements in soil organic matter. Economic analyses were conducted to estimate the effects of the proposed SSI interventions on farm-family economics in Dangeshta, a kebele in Dangila. These analyses compared the costs and benefits of five water-lifting technologies: pulley-and-bucket irrigation, and rope-and-washer pumps operated by hand, animal, gasoline motor, and solar power. Implementation of the proposed SSI interventions using gasoline-motor-powered rope pumps produced by far the highest net present value, net cash farm income, and ending cash reserves of the six scenarios simulated. The main barrier to SSI with motor pumps is the initial investment in the technology. However, the NPV results strongly suggest that an investment in a gasoline-motor pump would pay large dividends in increased income and wealth. Individual farmers might benefit by spreading entry costs over more irrigated area, perhaps by having two or three farmers share a motor pump. Accordingly, in Dangila, it is recommended implementing the proposed SSI interventions using a motor pump. The proposed SSI interventions increased farm-family economics, but nutritional deficiencies persisted under the simulated, improved cropping system. It is proposed expanding the types of crops irrigated in the dry season to increase family nutrition and net cash income, but only if such crops can be irrigated without causing excessive soil erosion or reduction in environmental benefits. The evaluation and comparison of alternative farming systems, including the types of crops grown, recommended management practices, and associated impacts on soil erosion and environmental benefits, are subjects for proposed future study. The analyses summarized in this report contribute to the third ILSSI component: estimating the impacts of proposed SSI interventions using the ILSSI's Integrated Decision Support System (IDSS). The IDSS is comprised of a suite of previously validated, interacting, and spatially explicit agroecosystem models: the Soil and Water Assessment Tool (SWAT), Agricultural Policy Environmental Extender (APEX), and Farm Scale Nutrition and Economic Risk Assessment Model (FARMSIM). The IDSS predicts short-term and long-term changes in crop and livestock production, farm economies, and environmental services produced by changing land uses, agricultural technologies and policies, climate, and water resources management, including SSI. The objective of this study was to use the IDSS to evaluate the benefits, environmental effects, and economic viability of proposed SSI interventions on farms in Dangila, a Feed-the-Future woreda in the Awi zone of the Amhara region of Ethiopia. Dangeshta, one of the rural kebeles located in Dangila woreda, is located about 80 km southwest of Bahir-Dar, one of the region's main markets. The region's climate is subtropical, and temperatures are ideal for cropping year-round, with a main rainy season from June to September and a dry season from October to January. There are an estimated 1766 ha of cropland in Dangeshta kebele, and about 661 ha of pastureland. The average household practices mixed-subsistence farming, cultivating a main crop of cereals in the rainy season. Some households also produce irrigated vegetable crops in the dry season. The main sources of irrigation water in the area are traditional river diversion and hand-dug wells. Currently, a number of households irrigate using motor pumps, mainly to divert water from rivers. Rapidly increasing population, economic growth, and the movement of the rural population to cities provide a