Rami Zurayk and Azza Dirar
Since agriculture consumes the largest share of the world’s water, farmers undoubtedly play an instrumental role in the management of this precious resource. As such, various policy approaches have sought to engage farmers in the management of water for irrigation. There is much literature on policy approaches that devolve irrigation management to farmers through organizing them into ‘water user associations’ and mobilizing them into cooperative water resource management. When the implementation experience and success of these approaches are assessed, the results show a great variation in experience with overall limited success. The key challenges stem from various assumptions underlying the policy approaches, namely the way in which farmers are conceptualized as a homogenous group of ‘water users’. Cooperative and participatory approaches to natural resource management cannot be institutionally manufactured without addressing key political ecological realities and the wider contexts in which ‘resource users’ operate.
Mustapha Besbes, Jamel Chahed, and Abdelkader Hamdane
Northwest African countries (NA) consume 70 percent of their renewable water resources, and groundwater overdraft has become a major problem. Blue water irrigation represents 17 percent of overall water resources and is economically significant. Green water represents 83 percent, but is not yet well evaluated, and is not considered in national water strategies, along with virtual water embedded in international food trade. Irrigation enhances local agrifood production but it has not changed the proportion of staple foods. The region remains a major net food importer and, largely due to population increase, water dependency increased from 30 percent to 50 percent between 1970 and 2010. Population forecasts predict that water demand will continue to grow, and could reach more than three times the present level. Given the blue water status, NA must develop approaches to cope with water–food challenges, based on international virtual water flow optimization and better green water valorization.
Peter Johnston and Arthur Chapman
Irrigation is a critical input for raising food production in southern Africa, parts of which are food-insecure, especially as a result of low levels of technology employed, low investments into the sector, small farm sizes, and high levels of exposure to the hazards of climate variability. Most food production (including exports) and irrigation in the region occurs in the arid south—in South Africa by a large margin. Further north, in Angola, Zambia, and the northern parts of Mozambique, water resources are abundant yet irrigation farming is far less developed and inefficient, resulting in water resources being less intensely managed. The region needs to become more tightly integrated economically, with a greater flow of technology, investment, and management capability to the north, allowing the north to produce more food (and other agricultural products) which would flow to the more industrialized south—essentially virtual water flows to that region.
West Asia is one of the most water-scarce regions of the world and one of its foremost importers of virtual water despite sustained efforts at self-sufficiency, especially in cereal production. Technology-oriented policy solutions eye a reorientation of agriculture towards fruit and vegetables that are less water-intensive than cereals and provide more value added per water unit consumed. Turkey is a role model here; the country has an agricultural trade surplus and ranks among the top ten agricultural economies globally in value terms. Yet technology-oriented policy prescriptions overlook the sociopolitical ‘problemsheds’ that emerge (along with new agro-lobbies) and agriculture as the main water consumer has to compete with other economic sectors and sprawling urbanization. This article looks at the different categories of countries and their specific challenges.
Brendan Bromwich, Tony Allan, Tony Colman, and Martin Keulertz
Society’s greatest use of water is in food production, a fact that puts farmers centre stage in global environmental management. Management of food value chains, however, is not well set up to enable farmers to undertake their dual role of feeding a growing population and stewarding natural resources. This chapter introduces an analytical framework by which food, water, and society can be investigated. Food value chains comprise three market modes: production, trade, and process; retail; and consumption. The model demonstrates the interfaces between blue water, green water, virtual water, polluted drainage, and evapotranspiration. By categorizing social, cultural, and political influences on the three market modes the framework enables integrated analysis of food, water, and society . The combined management of food and water through redesign of food value chains emerges as a key challenge for the twenty-first century.
Given that food production requires a lot of water, more than any other economic sector, one would expect that the world’s food production concentrates in places where water is relatively abundant. This chapter, however, highlights the paradox that various water-poor countries produce food for export to water-rich countries. Food commodity prices do not reflect the cost of water inputs or of damaged water ecosystems, so that the global food market lacks economic incentives to source from places with less harmful impacts on local water systems. The costs of ‘traded’ embedded water thus remain invisible. The chapter proposes an international water label for water-intensive products and argues that international trade rules should include regulations on sustainable water use.
Green water is defined as the water in soil that is potentially available to plants for uptake and subsequent transpiration. Despite the fact that crop biomass is directly related to transpiration and the global transpiration flow alone matches that of all the rivers in the world, green water has until recently been largely neglected in research on food security. That long neglect is redressed by a review of recent research on the role of green water in the production of agricultural commodities to meet current and future world food demand, including how the differences in water requirement between plant-based and animal-based commodities play out in respect to the food-water nexus. Informed by current literature, a case is made for optimizing green water management to achieve a global increase in food production from 20 to 40 percent without an expansion of either agricultural land use or the volume of water withdrawn for irrigation.
David Leslie Dent
All fresh water is delivered by the soil. There are two critical junctures: when rain hits the ground—where it may infiltrate or run off carrying the soil with it; and in the soil itself—where it may evaporate from a bare surface, be taken up by roots, or drain to streams and groundwater. Both partitions are managed by farmers so every land-use decision is a water-use decision. Green water is held in the soil and used by plants—the more green water, the more primary production; and the best soils supply orders of magnitude more than the poorest. Practices that maximize the green water resource, such as conservation agriculture, arrest soil erosion, maximize soil water storage and groundwater recharge, and moderate floods. But water consumed in the fields where it falls is not available for use elsewhere.
Oil palm is a key global crop, providing food and nonfood resources for billions of people. Two distinct types of oil, derived respectively from the fleshy mesocarp of the palm fruit and from the kernel (seed), are distributed via separate supply chains to markets in Asia, Europe, Africa, and the Americas. Oil palm is a tropical crop typically grown in high rainfall regions but yields have recently been reduced by water limitation due to changing climate patterns. In addition, over recent decades, indirect land use changes due to the expansion of oil palm into new regions have affected local hydrology and biotic components of these ecosystems. As the expansion of oil palm cultivation continues in order to meet growing consumer demand, especially in Asia, new research is beginning to address potential solutions to critical issues such as the environmental impact and biological performance of oil palm crops.
The Potential Impact of Improved Water Management to Alleviate Water Scarcity and Hunger: A Global Perspective
Dieter Gerten and Jonas Jägermeyr
In a world characterized by increasing demand for water and food and progressing global climate change, ever more regions are exposed to water shortages and resulting limitations to food production. In the present Anthropocene era, water scarcity is prevalent in many regions, and freshwater ecosystems are anthropogenically perturbed or severely degraded in many places. At the same time, the potential for further increasing the global irrigated area is limited. However, methods to improve agricultural water use—including upgraded irrigation systems, water harvesting, and soil moisture conservation—have tremendous potential to increase crop production and save water in farming systems, especially in regions with variable and aggravating hydroclimatic realities. Model simulations suggest that ambitious combination of such measures could increase global crop production by ~40 percent, thus significantly contributing to the simultaneous achievement of Sustainable Development Goals targeted to ensure water and food security. Successfully addressing this challenge requires ambitious policies supporting implementation of locally adapted solutions.