Using a 4Rs Plus approach to improve growth and sustainability of annual cropping systems in Saskatchewan
Term: 4 years, ending March 2026
Status: Completed
Researcher(s): Blake Weiseth, Discovery Farm; Jeff Schoenau, University of Saskatchewan
SaskCanola Investment: $108,100
Total Project Cost: $216,200
Funding Partners: SaskWheat
Project Description
4R Nutrient Stewardship is a tremendous success story of a decision support framework that has been widely adopted among Canadian Prairie farmers as an easily understood tool to optimize agricultural productivity through judicious fertilizer use and subsequently manage risk. However, despite the justifiable emphasis that has been placed on 4R Nutrient Stewardship, producers face significant risk related to managing water in the landscape as evidenced by the period of abnormally wet years from 2010-2014 which saw millions of acres of cropland impacted by flooding in Saskatchewan. On the other hand, risk of crop failure due to sub-optimal moisture conditions is also a relevant concern for many growers in the semi-arid climate of Saskatchewan. Significant uncertainty persists as to the impact that agricultural management practices may have on optimizing water use efficiency and the fate of applied fertilizer in run-off water. While it seems intuitive to conclude that the same practices suggested by 4R Nutrient Stewardship including sub-surface nutrient application at seeding and minimal tillage used to manage crop residue would lead to optimal water use efficiency, little field research has been conducted to support these claims. If validated through field research, the 4R Stewardship framework could easily be adapted to a “4Rs Plus” framework that includes a consideration of the impact that optimal water use efficiency has on influencing agronomic performance and limiting off-site losses of applied fertilizer in runoff water.
Objectives
Assess the impact of 4R Nutrient Stewardship practices on influencing N and P crop uptake and load in run-off water.
Assess the impact that variation in topography across landscape has on influencing N and P load in run-off water.
Conduct in-situ assessment of run-off water volume and nutrient characteristics as influenced by management practices evaluated.
Cost-benefit analysis of 4R and associated practices for production benefit and economic efficiency to reduce nutrient run-off.
Grower Benefits:
The VR fertilization treatment has shown benefit as a strategy to promote P use efficiency and to mitigate P losses from drained basins.
Overall, the highest grain yields were recorded from the VR fertilizer treatment.
The VR fertilizer treatment was the most profitable of those evaluated, due to the combined effect of the highest yield and reduced fertilizer costs compared to the control and tillage treatments.
The forage mixture treatment resulted in a significant reduction in soluble P concentration in simulated snowmelt runoff compared to the control treatment, likely due to applying approximately 50% of the P fertilizer rate across the landscape compared to the control.
Other References to this Research Project
Water Security Agency research article: The Agricultural Industry Advancing Water Management Research Projects
Blake Weiseth Water Management Project Presentation at 2022 Soils & Crops Workshop (click link to watch on YouTube or watch video below)