New projects:

Place-based phosphorus management: agronomic, environmental and economic benefits

Project team: Helen Baulch (U. Sask.), Jian Liu (U. Sask.), Jane Elliott (ECCC), Jeff Schoenau (U. Sask.), Melissa Arcand (U. Sask.) and David Lobb (U. Manitoba).

The project has just started in 2022 and is will be conducted at six sites in Saskatchewan and Manitoba. The main objectives are: (1) Assess variation in soil test phosphorus and its formation as influenced by soil, landscape and management characteristics; (2) Understand spatial yield patterns and their relationship with soil test phosphorus at different landscape positions; (3) Assess the risk of phosphorus runoff associated with elevated soil test phosphorus in hydrologically active areas; (4) Understand agronomic, environmental and potential economic benefits of place-based phosphorus management, and (5) Improve recommendations for use of place-based phosphorus management.

*If you’re interested in graduate studies, please reach out – we have positions available.

Recent results: 

Demonstration of the importance of targeting soil phosphorus (P) management in watershed P load reduction using the P Reduction Tool

Project team: Merrin Macrae (U. Waterloo), Jian Liu (U. Sask. & U. Manitoba), David Lobb (U. Manitoba), Henry Wilson (AAFC), Jane Elliott (ECCC) and Helen Baulch (U. Sask.).

In this project, we combined soil sampling, field management survey and modeling to examine the potential of soil P management to reduce P runoff. Main findings are: (1) Long-term soil P balance is a good indicator of soil test P and thus P loss potential; (2) Soil test P varies widely both between and within fields; (3) Our study watershed (the South Tobacco Creek Watershed) has an overall negative P balance over time, but about 1/3 of the agricultural land area still has very high soil test P concentrations; (4) The soils with high test P values are often associated with manure applications; (5) Management strategies of soil P drawdown and rebalancing soil P both potentially reduce watershed-level P loss; and (6) Effects of variable rate applications on field-level water quality and crop production likely vary with different types of fields.

Funded by Environment and Climate Change Canada’s Lake Winnipeg Basin Program.

Managing ditches to manage phosphorus transport.

This recently completed project, demonstrated the potential for managing ditch vegetation as a way of reducing nutrient concentrations in runoff.  We saw, much like in fields, that vegetative residue is a nutrient source to overlying water – and results suggest that harvesting vegetation in ditches can help decrease downstream phosphorus transport.  These results are relevant in low-gradient areas of the prairies where erosion risk is low.  Care must be taken in managing tradeoffs in terms of effects on wildlife habitat, and ensuring harvesting is done in a way that allows plant regrowth, and continues to minimize erosion risk.

Funded by Environment and Climate Change Canada’s Lake Winnipeg Basin Program.