Recent research studies and policies about innovative solutions to reduce water and energy consumption in food production are briefly reviewed. Options to increase water use efficiency and productivity include soil mulching, drip irrigation, deficit irrigation, and precision agriculture. As for the energy–water nexus, attention is focused on energy audits of water distribution networks; improving of system performance –– network sectoring, use of variable speed drives, critical points control, electricity tariff — and reduction of wastewater treatment’s energy use. At a larger scale, other solutions emerge: diversification and rotation of crops, cultivation of drought-resistant crops, and optimization process of the spatial distribution of cropping patterns. The rebound effect that can be associated to these options is also considered.

This article draws on three case studies of drip irrigation adoption in Morocco to consider the water–energy–food nexus concept from a bottom-up perspective. Findings indicate that small farmers' adoption of drip irrigation is conditional, that water and energy efficiency does not necessarily reduce overall consumption, and that adoption of drip irrigation (and policies supporting it) can create winners and losers. The article concludes that, although the water–energy–food WEF nexus concept may offer useful insights, its use in policy formulation should be tempered with caution. Technical options that appear beneficial at the conceptual level can have unintended consequences in practice, and policies focused on issues of scarcity and efficiency may exacerbate other dimensions of poverty and inequality.

The widespread uncertainty regarding future changes in climate, socioeconomic conditions, and population growth have increased interest in water-energy-food-ecology nexus-based frameworks in relation to the analysis of water resources. A challenge for modeling the water-energy-food-ecology nexus is how to reduce the multidimensional and codependent uncertainties and measure the complicated casual relationships effectively. We propose a methodological solution to the problem, and this solution is demonstrated in this case as an extension to the previous water resource optimization framework. We coupled the water-energy-food-ecology nexus into the Bayesian network, which provides a formal representation of the joint probabilistic behavior of the system, and the method was applied to water resource use analysis and management in the Syr Darya River basin, a transboundary and endorheic basin that has contributed to the Aral Sea ecological crisis as a result of unreasonable water use. The annual scale data of four periods, 1970–1980, 1980–1991, 1991–2005, and 2005–2015, were introduced into the Bayesian network. Before the disintegration of the Soviet Union, the amount of water inflow into the Aral Sea was sensitive to increases in irrigation for agricultural development, increases in water storage of the upstream reservoirs and stochastic runoff. After the disintegration of the Soviet Union, the amount of water inflow into the Aral Sea was sensitive to the inefficient irrigation water use in the downstream areas of Uzbekistan and Kazakhstan and the water storage of the reservoir located upstream of Kyrgyzstan. The change resulted from unresolvable disputes between water use for power generation in the upstream area and irrigation in the downstream area. Comprehensive scenario analysis shows that, in the short term, it would be useful to improve the proportion of food crops, improve the efficiency of water use in relation to salt leaching and irrigation, and prevent drought damage. In the long term, based on the increased use of advanced drip irrigation technology from 50% to 80%, the annual inflow into the Aral Sea will increase significantly, reaching 6.4 km³ and 9.6 km³, respectively, and this technology is capable of ameliorating the ecological crisis within the basin.

The potential impacts of climate variability and change on water resources and food security are receiving growing attention especially in regions that face growing challenges meeting water demands for agricultural, domestic and environmental uses. Rainfed agriculture regions exhibit higher vulnerability to climate variability and change, where aquifer storage and food security are under stress. Little research has attempted to investigate the consequences of climate variability and change on water availability and social livelihoods jointly. Employing available data on precipitation, farm budget data, and aquifer characteristics, a dynamic nonlinear optimization framework that maximizes the economic likelihoods of irrigation activities and food security under several climatic assumptions is developed and applied for Barbados as a numerical example. Our framework accounts for technological adaptation measure, drip irrigation, with the context of variable yield and cost of water demand under governmental subsidy schemes. Results indicate significant negative impacts of climate variability, change, and double exposure on future water resources and food security. However, some climate assumptions provide opportunity for some food producers who respond positively to technological adaptation programs, while consumers could face the major negative consequences by experiencing higher food prices. Our findings provide policymakers and stakeholders a comprehensive tool for economically efficient and sustainably reliant policy design, implementation, and evaluation facing the potential climate variability and change impacts.

Cape Verde, which has agricultural land that is mainly rainfed, will be severely affected by climate change due to increased drought conditions. Scarce water availability makes this country highly dependent on imports for its food supply, resulting in more than 80% food importation. Improving water use efficiency, implementing precision irrigation could help achieve sustainable use of water resources. Cereal production reusing treated water could contribute to strengthening resilience and adaptation to climate change in Cape Verde. Our pilot project demonstrates that the safe and profitable reuse of water produced by Cape Verde’s water treatment plants is possible by avoiding water and plant contact using Subsurface Drip Irrigation (SDI), obtaining food yields between 10,000 and 7000 kg of cob/ha, with a water consumption of about 300 L/kg Dry-Matter and a Water-Use-Efficiency of about 3 g/L. These studies also showed that it is necessary to provide training to farmers and to conduct further studies to help solve present challenges. This project identif installation failures as water shortages can compromise farmers’ profitability. To guarantee the sustainability of water reuse, it is also necessary to consider economic and social factors, including that all water that is not reused is poured, increasing environmental and sanitary risk and decreasing the possibility of recovering water treatment costs.

Irrigation water coming from freshwater bodies that suffer toxic cyanobacterial blooms causes adverse effects on crop productivity and quality and raises concerns regarding food contamination and human exposure to toxins. The common agricultural practice of spray irrigation is an important exposure route to cyanotoxins, yet its impact on crops has received little attention. In the present study we attempted an integrated approach at the macro- and microscopic level to investigate whether spray or drip irrigation with microcystins (MCs)-rich water differently affect spinach performance. Growth and functional features, structural characteristics of stomata, and toxin bioaccumulation were determined. Additionally, the impact of irrigation method and water type on the abundance of leaf-attached microorganisms was assessed. Drip irrigation with MCs-rich water had detrimental effects on growth and photosynthetic characteristics of spinach, while spray irrigation ameliorated to various extents the observed impairments. The stomatal characteristics were differently affected by the irrigation method. Drip-irrigated spinach leaves showed significantly lower stomatal density in the abaxial epidermis and smaller stomatal size in the adaxial side compared to spray-irrigation treatment. Nevertheless, the latter deteriorated traits related to fresh produce quality and safety for human consumption; both the abundance of leaf-attached microorganisms and the MCs bioaccumulation in edible tissues well exceeded the corresponding values of drip-irrigated spinach with MC-rich water. The results highlight the significance of both the use of MCs-contaminated water in vegetable production and the irrigation method in shaping plant responses as well as health risk due to human and livestock exposure to MCs.