Agriculture production is highly dependent on water and increasingly subject to water risks. It is also the largest using sector and a major polluter of water. Improving agriculture’s water management is therefore essential to a sustainable and productive agro-food sector.
In recent years, agricultural regions around the globe have been subject to extensive and increasing water constraints. Major droughts in Chile and the United States have affected agricultural production while diminishing surface and groundwater reserves. These and other extreme weather events, like floods or tropical storms, are also expected to be more frequent. Climate change is projected to increase the fluctuations in precipitation and surface water supplies, reducing snow packs and glaciers and affecting crop water requirements.
Agriculture both contributes to and faces water risks
As much as agriculture is impacted by these changes, it also contributes to the problem as a major user and polluter of water resources in many regions. As such, agriculture has a central role to play in addressing these challenges.
Irrigated agriculture remains the largest user of water globally, a trend encouraged by the fact that farmers in most countries do not pay for the full cost of the water they use. Agriculture irrigation accounts for 70% of water use worldwide and over 40% in many OECD countries. Intensive groundwater pumping for irrigation depletes aquifers and can lead to negative environmental externalities, causing a significant economic impact on the sector and beyond. In addition, agriculture remains a major source of water pollution; agricultural fertiliser run-off, pesticide use and livestock effluents all contribute to the pollution of waterways and groundwater.