SDG 17 underscores the pivotal and interconnected role of water, including its energy implications, in addressing challenges related to human well-being and sustainable development. Solar water pumps (SWPs) offer an important technological innovation exemplifying this water–energy–food–society nexus. As a comparatively new and eco-friendly approach to irrigation, SWPs have the potential to substantially benefit millions of smallholder farmers in sub-Saharan Africa (SSA). With costs for solar products steadily reducing, the small-scale SWP market is expected to grow in sales and expand into new territories. Overall, the region’s groundwater resources are known to be greatly underutilized and hence enable greater SWP adoption. This study assesses the possible risks to groundwater resources from SWP expansion to the year 2030. The current market environment is extremely heterogeneous across regions and countries. It is conservatively estimated that up to 10,000 units are sold each year, with the strongest markets found in East Africa. Around 100,000 SWP units are estimated to be in operation. For projected rates of annual growth spanning from 6% to 18%, along with intentionally high estimates of groundwater pumping, the upper limit on the quantity of available groundwater pumped by small SWP development to 2030 would vary from 0.4% to 0.6% at the SSA scale. Values in the regions vary from a low of <0.1% for Central Africa through to a high of 1.6%–2.1% for Southern Africa. Specific countries may generally support additional SWPs ranging from tens of thousands up to millions of units without negatively impacting on groundwater availability. Countries characterized by greater recharge and lower current groundwater use can accommodate greater numbers of SWP systems. Short-term threats to the availability of groundwater are assessed to be low over the short and medium terms. Over the long term, risks to groundwater may be greater than evaluated in this study should SWP growth rates exceed the projected range or if improvements in technology allow for stronger, small-capacity pumps to flood the market. To address long-term groundwater management challenges, key action areas have been defined that recognize the diverse conditions across the regions.

Groundwater depletion in India is a result of water, energy, and food policies that have given rise to a nexus where growth in agriculture has been supported by unsustainable trends in water and energy use. This nexus emanates from India’s policy of providing affordable calories to its large population. This requires that input prices are kept low, leading to perverse incentives that encourage groundwater overexploitation. The paper argues that solutions to India’s groundwater problems need to be embedded within the current context of its water-energy-food nexus. Examples are provided of changes underway in some water-energy-food policies that may halt further groundwater depletion.

Using water-energy-food-environment (WEFE) nexus as the prism, this review explores evolution of groundwater governance in Iran, Saudi Arabia, Mexico, China, Bangladesh and India – which together account for two-thirds of the global groundwater-irrigated area. Global discourse has blamed widespread water scarcity squarely on supply-side policymaking and advocated a broader template of water governance instruments. Integrated Water Resources Management (IWRM) presented just such a template – with pricing, participation, rights and entitlements, laws, regulations, and river basin organizations – as additional water governance tools. However, the IWRM template faced disillusionment and pushback in many emerging economies. WEFE nexus, the new paradigm, prioritizes system-level optima over sectoral maxima by harnessing synergies and optimizing trade-offs between food, water, energy, soil, and eco-system sustainability within planetary boundaries. Realizing this vision presents a complex challenge in groundwater governance. Global groundwater economy comprises three sub-economies: (a) diesel-powered unregulated, as in Nepal terai, eastern India, Bangladesh, Pakistan Punjab and Sind, and much of Sub-Saharan Africa, where use-specific energy subsidies are impractical; (b) electricity-powered regulated, as in North America and Europe, where tubewells are authorized, metered and subject to consumption-linked energy charges; and (c) electricity-powered unregulated, as in geographies covered by our review – barring China, Bengal and Bangladesh – where unmeasured electricity subsidies have created a bloated groundwater economy. This last sub-economy represents the heartland of global groundwater malgovernance, least equipped to meet the sustainability challenge. It has an estimated 300 million horsepower of grid-connected electric pumps that are either unauthorized and/or unmetered and/or use free or heavily subsidized or pilfered power for irrigating 50–52 million hectares, nearly half of global groundwater-irrigated area. In (a) and (b), groundwater scarcity inspires water-energy saving behavior via increased energy cost of pumping. In sub-economy (c), users are immune to energy costs and impervious to groundwater depletion. Here, the WEFE nexus has remained blind to the irrigation realpolitik that catalyzes or constrains policy action. We explore why the political costs of rationalizing subsidies are prohibitive and exemplify how a smart transition from fossil to solar energy for pumping may offer an opportunity to turn the perverse WEFE nexus into a virtuous one.

Most of secondary crops in Indonesia are grown on dry land and rainfed lowland condition. Under dry land condition maize, peanut and soybean are planted in early wet season; and late wet season under rainfed lowland in order to make use of available moisture. However, insufficient rainfall often occurs during the growing season of the crops. Application of water pump is necessary to provide enough moisture for plants, particularly in intensification program of production system. Appropriate use of water pump is determined by its type and engine, discharge capacity, irrigation method, and crops. Several types of water pump have been developed by RIMC (previously, MORIF). This paper describes and reviews some technical specification of water pumps and irrigation method for maize, soybean, and peanut. Financial analysis of the water pump application is presented. A modified axial pump, 8 inches in diameter (PS-3), used under riverbank of less than 30 deg. in slope, suction lift of less than 4 m has discharge less than capacity of 134.1 cubic meter/h. Provided that water requirement for maize, peanut, and soybean were 420, 351, 271 mm/ha/season, respectively, application of the water pump would be able to irrigate 26.4 ha, 31.6 ha, and 40.9 ha of maize, peanut, and soybean crops, respectively. Effective use of the water pump in maize is attairable when 50 percent ETA of water requirement is supplied during the first four weeks after planting then all (100 percent ETA) of the water need should be supplied for the later stages of the crop. In peanut effective application is achievable when water is pumped every 14 days (70 mm/ha/season) during vegetative stage followed by more frequent every 7 days (35 mm/ha/season) pumping during generative stage. In soybean, application of water pump is recommended every 14 days beginning post emergence up to maturity stages. All of the mentioned practice water distribution apply furrow irrigation method. The result of the financial analysis for water pump rental business showed B/C ratio 2.06; IRR 106.55 percent and BEP 5.60 ha/season/year | Sebagian besar produksi tanaman pangan (palawija) di Indonesia pada lahan kering dan sawah tadah hujan. Pada umumnya, tanaman jagung, kacang tanah dan kedelai tumbuh pada awal musim hujan di lahan kering dan akhir musim hujan pada sawah tadah hujan. Selama satu tahun pertanaman, palawija mengalami keterbatasan ketersediaan lengas tanah. Intensifikasi pertanaman palawija pada lahan kering dan sawah tadah hujan perlu penggunaan pompa air. Penggunaan pompa air ditentukan antara lain: tipe pompa dan enjin, kapasitas pemompaan, cara pemberian air dan jenis tanaman. Beberapa tipe pompa air telah dikembangkan oleh Balittan atau Balitjas. Makalah ini menyajikan spesifikasi pompa air, cara pemberian air pada tanaman jagung, kedelai dan kacang tanah dan analisis finansial. Modifikasi pompa aksial (pompa sepak) ukuran diameter 8 (PS-3) inchi pada kondisi tebing sungai kurang dari 30 derajat, daya capai kurang dari 4 m, dan mempunyai kapasitas pemompaan 134,1 meter kubik/jam. Pemberian air dengan pompa ini (420 mm/ha/musim, jagung); (351 mm/ha/musim, kacang tanah); (271 mm/ha/musim, kedelai) adalah cukup untuk mengairi seluas 26,40 ha tanaman jagung; 31,58 ha tanaman kacang tanah; dan 40,93 ha tanaman kedelai. Kinerja pompa ini menjadi baik dan dapat meningkatkan hasil dan berat berangkasan pada saat pemberian air 50 persen ETA mulai perkecambahan sampai dengan pemantapan tumbuh untuk tanaman jagung setiap 14 hari sekali (70 mm/ha/musim) pada fase vegetatif kemudian 7 hari sekali (35 mm/ha/musim) pada fase generatif untuk tanaman kacang tanah, setiap 14 hari sekali pada saat fase perkecambahan sampai dengan menjelang panen untuk tanaman kedelai. Metode pemberian air umumnya adalah alur terbuka. Analisis finansial untuk pemilik pompa air menunjukkan bahwa B/C ratio 2,06, IRR 106,55 persen dan BEP 5,60 ha/musim/tahun

With adverse impacts of climate change growing in number and intensity, there is an urgent need to reduce emissions from food systems to net zero. This can only be achieved if rural areas in low- and middle-income countries gain access to clean energy. A review of the research and capacity building contributions of the CGIAR Research Program on Water, Land and Ecosystems (WLE) over the last 10 years suggests important contributions in the areas of energy policy and energy investment planning, cost and feasibility frameworks, and business models for clean energy technology uptake. WLE has also conducted successful pilot projects on solar irrigation to provide an evidence base for scaling up innovative energy initiatives. Finally, the program also considered non-agricultural uses of energy where relevant to food systems, and implemented capacity building activities. Going forward, CGIAR has a key role to play in providing information, supporting access and piloting innovative, scalable clean energy interventions to support the achievement of multiple impacts for the poorest and most food-insecure women and men farmers and entrepreneurs.

Irrigation plays a crucial role in enhancing food production, increasing land productivity, and improving the livelihoods of smallholder farmers in Sub-Saharan Africa (SSA). Solar pumps and water harvesting ponds have emerged as promising technologies for sustainable agriculture for smallholders in SSA and beyond. The socio-economic impacts of these systems are less studied in the existing literature. This study examined the agricultural productivity of solar pump and water harvesting irrigation technologies and their impacts on income and food security among smallholder farmers in the Central Rift Valley, Lake Hawassa, and Upper Awash sub-basin areas in Ethiopia. Data were collected from 161 farming households that were selected randomly from woredas where solar pump and water harvesting pond irrigation systems had been implemented. The sample size was determined using the power calculation method. Bio-physical observation and measurements were also conducted at field levels. The benefit–cost ratio (BCR) and net water value (NWV) from the use of solar pump and water harvesting pond irrigations were analyzed to assess the viability of these systems. The household food consumption score (HFCS) and household dietary diversity score (HDDS) were calculated to measure food security, while the revenue from crop production was used to measure crop income. An endogenous switching regression model was applied to address the endogeneity nature of the adoption of the irrigation technologies. The counterfactual analysis, specifically the Average Treatment Effect on the Treated (ATT), was used to evaluate the impacts of the irrigation technologies on income and food security. Results indicate that the ATT of crop income, HFCS, and HDDS are positive and statistically significant, illustrating the role of these irrigation systems in enhancing smallholder farmers’ welfare. Moreover, smallholder farmers’ solar pump irrigation systems were found to be economically viable for few crops, with a BCR greater than 1.0 and an NWV ranging from 0.21 to 1.53 USD/m³. It was also found that bundling agricultural technologies with solar pump irrigation systems leads to enhanced agricultural outputs and welfare. The sustainable adoption and scale-up of these irrigation systems demand addressing technical and financial constraints, as well as input and output market challenges.