Soil health

Healthy soils form the basis of productive farming systems by providing essential ecosystem services such as nutrient recycling, carbon sequestration, and water supply. But, how can you tell whether you have healthy soil or not, and what can you do to improve it? To address these questions, we evaluate soil health indices and soil health testing protocols. We are focused on prairie field crop systems producing cereals, oilseeds, or pulses – as well as intensive vegetable production systems where there is a higher risk of soil health degradation. In addition to evaluating testing protocols, we measure the effects of various soil conservation practices and agroecological practices on soil health attributes.

Nutrient cycling and stable isotopes

Intensive production presents a significant challenge for nitrogen management because many crops require large quantities of N-fertilizer (i.e., 100 to >300 kg N ha^-1) to maximize yields and profits, yet these systems can be highly vulnerable for nitrogen loss - resulting in negative environmental impacts (surface/groundwater contamination, air pollution). Thus, we evaluate the effects of conservation practices on soil nitrogen cycling mechanisms and nitrogen loss dynamics. We use stable isotopes (¹⁵N & ¹³C) to trace the fate and flow of nitrogen and carbon compounds through agroecosystems to better understand processes in soil biogeochemical cycling.

Greenhouse gas emissions

Using farm-inputs more efficiently without negatively impacting yield would not only benefit producers by optimizing production and conserving soil health, it would also come with an environmental benefit: reduced potential for greenhouse gas emissions. In cold climate regions such as western Canada, nitrous oxide (N₂O) emissions (a potent greenhouse gas) are enhanced by soil freeze-thaw cycles, which can contribute to a significant portion of cumulative annual emissions from soils. The specific conditions responsible for the magnitude of N₂O pulses during soil freeze-thaw are complex and poorly understood; a warming/more variable climate might increase the frequency, duration, and spatial extent of soil freeze-thaw events. In heavily fertilized, tilled, and irrigated systems, the risk of emissions might be heightened due to high moisture conditions and high nutrient availability. With the goal of developing best practices to mitigate climate change, we conduct field, lab, and isotopomer studies focused on understanding N₂O dynamics and driving mechanisms.

Crop nutrient use efficiencies

Improving nutrient use efficiency is good for the environment and for growers. We evaluate the effect of agronomic management on crop nutritional status throughout the growing season and at harvest. To address specific research questions on crop nutrition, we take a systems-approach by integrate numerous soil, microbial, plant, and abiotic variables over short (annual) and longer-term durations (crop sequences, rotations).

Nutrient cycle modelling

To complement our fundamental research focused mechanisms regulating soil biogeochemical cycling, we use tools (DayCent and DNDC) to test and improve the predictability of nutrient flows under different environmental and management scenarios.