Coordinating agronomist: Frédérique Lavallée
Organization: Écoboeuf
Practice: Nitrogen management, Rotational grazing
Trial started: Spring 2026
Barrier: Mixed legume-grass pastures are the norm for many beef producers and can supply nitrogen through symbiotic fixation. However, sulfur deficiencies can reduce legume vigour, resulting in declining pasture productivity, leading more producers to consider synthetic nitrogen fertilizer. Although synthetic nitrogen can increase forage yield, it carries economic and environmental costs and can further reduce legume content in mixed stands. Producers lack regionally relevant, commercial-scale evidence that sulfur fertilization combined with legume overseeding can sustain pasture productivity and reduce reliance on synthetic nitrogen.
Description: A randomized field trial on a commercial beef farm in Quebec’s Clay Belt region will evaluate whether sulfur fertilization can improve legume establishment, symbiotic nitrogen fixation, and forage productivity under rotational grazing. Overseeded pasture plots will receive either potassium sulfate, a fast-release sulfur source; lower-cost, slow-release elemental sulfur; or no sulfur fertilizer. Legume establishment, composition, forage yield and quality, and treatment economics will be assessed to determine whether correcting sulfur deficiencies can help mixed pastures provide a practical and economically viable alternative to synthetic nitrogen fertilization.