Agricultural Water Futures

The predicted rise in earth’s temperature by 1.5°C as early as 2030 could have an enormous impact on Canada’s agricultural systems. Successfully adapting to and mitigating associated risk requires understanding what these changes mean for our food production systems and the people that depend on them.

To maintain Canada’s future food security under these conditions, the Agricultural Water Futures (AWF) research team explored hydroclimatic impacts in agriculture while considering different soil types, land use practices, as well as the role of economic incentives and human behaviours.

Researchers found that crop vulnerability to moisture stress varies across regions. Moisture stress is a common issue in the Prairies but less so in the Great Lakes, which has a more humid climate. This suggests that future warmer conditions, including extreme heat, may require a transition to more climate resilient crops in the Prairies.

Researchers also found that factors driving water quality differ in the Great Lakes compared to the Prairies. In cold regions like Canada, most of the nutrients in agricultural runoff are released into water bodies during snowmelt. While this pattern is most apparent the Prairies, the changing climate in the Great Lakes is leading to more frequent snowmelt periods. Changes in runoff patterns are influencing the timing and speciation of nutrient losses in both regions.

Another difference is in how nutrients are flowing from fields to water bodies. In the Prairies, most of the phosphorus moves as surface runoff and very few nutrients travel in the subsurface. In the Great Lakes, there is more variability in nutrient pathways. In some regions, such as those with sloping ground and coarser soils, most phosphorus is lost in the surface and less through subsurface (tile drainage), whereas in clay soils, most nutrients are lost in tile drainage (subsurface).  These differences can also impact relationships between soil phosphorus concentrations and runoff losses, and thus our ability to predict nutrient losses in runoff. Climate may change the way water flows between the surface and subsurface and this has implications for water quality and protection strategies.

Another key difference is the efficacy of different conservation practices. For example, cover crops can be effective at keeping nutrients on fields in warmer temperate zones, whereas in the colder prairies, cover crops can exacerbate phosphorus issues by releasing dissolved phosphorus following freezing.

Through new tools and solutions, AWF researchers are helping specialists across Canada’s agricultural community – producers, managers, extension specialists, businesses, conservation authorities, researchers, and policy experts – adapt to a changing climate, both now and in the future.

AWF researchers developed and/or enhanced several predictive tools:

• Integrated crop models improve understanding of the interactions between crops (type, planting, growth, harvesting) and watershed hydrology to help identify suitable crop choices and management practices in different regions.
• Crop water use models now account for variables such as carbon exchange and productivity, meaning we can compare crop water use and efficiency to estimate changing water needs for specific crops.
• Drones and remote sensing are used to estimate rates of evapotranspiration at much larger scales than was previously possible.
• Hydrological models now include modules for nitrogen and phosphorus dynamics, surface and tile drainage runoff at the field scale, and soil nutrient cycling. This helps predict how beneficial management practices can protect water quality in different regions and climates.
• Regional toolkits make recommendations for beneficial management practices (BMPs) according to physiographic regions within the broader climate zones.