A recent analysis reviews 175 crops across a 1990 through 2019 period, distinguishing rainfall-based green water from irrigation-driven blue water to map global farming trends. The study reports water footprints per tonne of crop produced, providing a practical gauge of resource intensity for farmers, policymakers, and consumers. It highlights where water resources are stretched and where savings can be found in major farming systems around the world. The work also emphasizes how green and blue water interact with climate, soil, and crop choices, shaping water sustainability in agriculture.
By 2019, almost 80 percent of the crops studied used less water per tonne than in 1990, signaling efficiency gains across many cropping systems. Yet the total global water footprint for agriculture rose by about 30 percent, reaching roughly 6.8 trillion cubic meters per year and translating to about 2,400 litres per person per day. The persistence of overall water use despite gains in efficiency points to growth in production and rising demand. In practice, this means smarter irrigation and better crop varieties help some farms use water more productively, while overall consumption increases in many regions due to expanding food production and changing consumption patterns. This has clear implications for policy planning in water-scarce areas, where decisions about allocation and technology can influence how water supports food systems.
Three socioeconomic forces account for most of the rise between 2000 and 2019. First, faster globalization and economic growth boosted demand for imported crops and plant-based products, shifting water use across borders. Second, dietary shifts toward foods that typically require more water to produce—including animal products, sugary drinks, and fatty or sugary items—have raised water use in food supply chains. Third, energy security policies in many governments supported crop-based biofuels, expanding irrigation needs in several regions. In the United States, China, and India, irrigation footprints grew as these dynamics unfolded, with much of the increase concentrated in tropical regions where land-use change adds environmental pressures.
Among the world’s big users, India, China, and the United States stand out, though the overall rise has often been strongest in tropical zones and has been linked to deforestation and biodiversity loss in those areas. The ecological consequences extend to river regimes, soil health, and local ecosystems, underscoring the need to balance yields with long-term resource stewardship. The analysis points to opportunities to boost crop-water productivity, relocate production to regions with lower water stress when feasible, promote diets that rely on less water-intensive foods, and rethink the role of first-generation biofuels that compete for water resources.
Practical steps include improving irrigation efficiency, adopting precision agriculture, and expanding water recycling while aligning crop choices with regional water availability. In Canada and the United States, this translates into policies and investments that support efficient irrigation, sustainable crop mixes, and water management strategies that fit local hydrology. The central message is that a combination of farming innovation, trade adjustments, and informed policy can reduce water pressure without sacrificing food security or affordability.
Beyond farm-level actions, the study stresses the importance of tracking groundwater reserves alongside river flows and rainfall-driven use. In North America, water managers balance surface and groundwater to support crops during droughts while protecting ecosystems in major agricultural regions. The overarching takeaway is that cutting water footprints requires coordinated efforts across trade, energy, and land-use policy, with transparent metrics that reveal where water stress is highest and where savings are achievable.