WATER QUALITY AND MANAGEMENT PRACTICES
Research progress
01
UNDERSTANDING THE INTERACTIONS BETWEEN CLIMATE, LANDSCAPE AND MANAGEMENT DRIVERS ON NUTRIENT LOSS
Nutrient loss from agricultural fields is a complex process. We examined how external drivers – such as climate, landscape conditions, and land management practices – affect nutrient loss, particularly during cold seasons. We also looked at how feedlots on dairy farms change the underlying hydrogeology (water levels, soil moisture) and geochemistry, as well as how these changes impact nutrient runoff into watercourses.
02
INTEGRATING WATER QUALITY COMPONENTS INTO HYDROLOGICAL MODELS
Many Canadian hydrological models do not include water quality components. Our team has addressed this gap by incorporating modules for nitrogen and phosphorus dynamics, surface and tile drainage runoff at the field scale, and soil nutrient cycling in agricultural basins. We have also developed a smartphone-based app, The Nutrient App, designed for land managers and practitioners, for on-site water quality monitoring for wells, rivers, lakes, and wetlands.
03
DETERMINING KEY DRIVERS OF PHOSPHORUS LOSS IN THE PRAIRIES
We found a strong correlation between phosphorus losses in runoff and soil test phosphorus in surface soils in the Prairies. This indicates that phosphorus loss in runoff contributes to high phosphorus levels in soils. We found that we can reduce phosphorus losses in soils, and therefore reduce the phosphorus loss in runoff, by lowering fertilizer inputs and allowing crops to decrease soil phosphorus levels – all without impacting crop yields.
04
EXAMINING THE IMPACTS OF TILE DRAINAGE ON NUTRIENT RUNOFF ACROSS CANADA
We found that tile drainage impacts surface and edge-of-field runoff differently in the Prairies than in the Great Lakes region. In the Prairies, phosphorus is lost mainly from surface runoff because frozen soils act as a barrier to the tiles. In the Great Lakes, tile drainage is a primary pathway for phosphorus loss from fields. However, the role of tile drainage in phosphorus loss differs sub-regionally in the Great Lakes depending on the soil type and whether it is the growing or non-growing season.
Key messages
01
BENEFICIAL MANAGEMENT PRACTICES FOR PHOSPHORUS MANAGEMENT WORK DIFFERENTLY IN COLD AND WARM CONDITIONS
By understanding the different climate and landscape drivers of phosphorus loss, we can identify targeted beneficial management practices that will mitigate phosphorus losses in agricultural fields. For example, controlling the supply of phosphorus to runoff through improved fertilizer and manure application can have a major effect in cold regions where management practices like cover crops or riparian zones don't work as well.
02
HYDROLOGICAL MODELS FOR COLD SEASON PROCESSES NEED TO ACCOUNT FOR WATER QUALITY
Water quality modules adapted for use in cold regions are necessary to account for important water quality processes such as runoff and nutrient loss in Canadian landscapes. These should be included in existing hydrological models to show how beneficial management practices for phosphorus management work differently in cold and warm conditions.
03
BENEFICIAL MANAGEMENT PRACTICES SHOULD BE TAILORED TO DIFFERENT LANDSCAPES ACROSS CANADA
Our research shows that regional differences in climate, landscape, and management practices have an impact on which beneficial management practices work best. This emphasizes the need for adopting management practices and programs that are locally tailored and informed by regionally grounded science.
04
REGIONAL WINTER CONDITIONS HAVE AN IMPACT ON BENEFICIAL MANAGEMENT PRACTICES
Beneficial management practices perform differently across Canada because they are impacted by the varying severity of winter. For example, in the Prairies, cover crops can release phosphorus during the spring runoff period because of the harsh frost that they are exposed to throughout the winter. However, in the warmer winters of the Great Lakes region, where frosts are less severe, cover crops do not appear to release as much phosphorus following freezing periods.
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