Measuring the impact of different proportions of legumes in cover crop mixes on nitrogen credits in a subsequent corn crop

Coordinating agronomist: Florence Pomerleau-Lacasse
Organization: Agri Conseils Maska
Practices: Cover crops, nitrogen management
Trial started: Fall 2025

Barrier: Leguminous cover crops can supply nitrogen to the following crop and potentially reduce synthetic fertilizer needs, but legume cover crops can have a wide range of seed costs depending on species. There is a lack of local data on what species and proportion of legumes optimize biomass, nitrogen contribution and economic return.

Description: On four farms, two cover crop mixes (oats, radish and forage peas or fava beans) will be planted side by side after a cereal crop with <50% legumes and >70% legumes. Cover crop biomass and quality will be measured. In the subsequent corn crop, test strips with only starter fertilizer will be compared to standard rates. Changes in soil nitrate, corn stalk nitrate, and corn yield will be measured, and the economics evaluated to determine the legume proportion that delivers the best agronomic and economic value.

Evaluating the latest planting date for establishing cover crops after spring cereal, soybean and silage corn crops

Coordinating agronomist: Isabelle Dubé, Emmanuelle Robertson
Organization: Groupe PleineTerre inc.
Practice: Cover crops
Trial started: Fall 2025

Barrier: The lack of regional data on the latest viable planting dates for cover crops makes it difficult to develop reliable recommendations for farmers. In corn–soybean–cereal rotations, the very short planting window after harvest limits the adoption of cover crops and there is uncertainty about the agronomic and economic benefits.

Description: These trials compare standard and late fall planting dates to evaluate cover crop establishment. Trials include 

• Fall rye (160 kg/ha) drilled after spring cereals on September 15, October 1, and October 15; 

• Oats (50 kg/ha) and radish (4 kg/ha) drone-seeded into soybeans at R6 and R7; and 

• Fall rye (160 kg/ha) seeded after corn silage on October 15 and 25. 

Cover crop performance will be evaluated in late fall, including ground cover and biomass, and a partial-budget analysis completed.

Evaluating nitrogen credits from leguminous cover crops in colder regions to guide nitrogen fertilizer management in potatoes

Coordinating agronomist: Yolaine Filion
Organization: Club d’encadrement technique pommes de terre
Practices: Cover crops, nitrogen management
Trial started: Fall 2025

Barrier: Potatoes are heavy feeders, and under- or over-applying nitrogen can affect plant health, yield and quality. In colder regions with shorter growing seasons, uncertainty about nitrogen credits from leguminous cover crops makes it difficult for potato growers to confidently adjust synthetic nitrogen fertilizer rates.

Description: This replicated split-plot trial will compare a legume cover crop (forage peas) seeded after canola harvest with a no cover crop control. Three post-emergence nitrogen (N) rate treatments will be applied: the grower’s standard nitrogen rate and two reduced rates (15 kg N/ha and 30kg of N/ha below standard). Cover crop biomass, soil and petiole nitrate levels and potato yield and tuber quality will help quantify nitrogen credits, while an economic analysis will evaluate the feasibility of adjusting synthetic fertilizer rates accordingly.

Intercropping cover crops in grain corn: evaluating seeding methods

Coordinating agronomist: Camille Dumont
Organization: Groupe ProConseil
Practice: Cover crops
Trial started: Fall 2025

Barrier: Adding cover crops in a corn rotation can be challenging due to the short post-harvest growth window, wet conditions at seeding time that can result in compaction, and limited access to specialised equipment. Drone seeding into standing corn offers a quick and potentially more affordable alternative, but this practice is still new in the region. It is therefore necessary to document methods, timing, and seeding rates in order to identify effective and cost-efficient approaches that promote reliable establishment and improvements in soil health.

Description: Four farms will participate in this trial. One farm will compare 1) 10kg/ha of broadcast Italian ryegrass at the same time as nitrogen sidedress application into corn, with 2) Italian ryegrass drone-seeded preharvest at 25 kg/ha, and 3) a no cover crop control. The other farms will drone-seed radish or winter canola pre-corn harvest at 15 kg/ha and 25 kg/ha, compared to a no cover crop control. Corn yield, cover crop growth, and soil structure data will be collected, and an economic comparison conducted.

Adaptive nitrogen trials in corn following cover crops

Coordinating agronomists: Lorraine Vandermyden, Jackie Clark
Organizations: The Ontario Soil Network and Ecological Farmers Association of Ontario
Practices: Cover crops nitrogen management
Trials started: Summer 2025 and Summer 2026

Barrier: Nitrogen is a critical and costly input, with economic and environmental consequences if not managed carefully. As farmers adopt beneficial management practices such as cover cropping to improve nutrient cycling and increase flexibility in nitrogen management, the lack of local, field-level data on how much nitrogen can be reduced in corn following a legume cover crop without compromising yield or profitability remains a key barrier.

Description: This replicated strip trial will be conducted on 12 farms across Ontario and will compare the farmers’ standard nitrogen (N) application rates with reduced nitrogen application rates (by at least 20 lbs N/acre) in corn following cover crops. Farms may choose to include a zero/near-zero nitrogen control. Yield, soil, and economic data will be combined with farmer observations to understand outcomes.

Evaluating the profitability and productivity of enhanced efficiency fertilizers (EEFs) on irrigated winter wheat systems

Coordinating agronomist: Jamie Puchinger
Organization: Farming Smarter
Practice: Nitrogen management
Trial started: Fall 2025

Barrier: There is limited data on the cost-benefit analysis of the use of EEFs on a fall-seeded winter wheat crop under irrigation in the Prairies.

Description: This study aims to evaluate the use of EEFs in irrigated winter wheat systems in southern Alberta. A replicated strip trial will compare two rates of fall-applied urea (at 100% and 80% the recommended rate) with and without the use of a dual inhibitor (Anvol and Centuro U-Pro) to a check (with no nitrogen). Soil samples, emergence counts, canopy closure, vigour, biomass and aerial imagery will be captured in this trial. Grain yield and quality will also be measured and nitrogen use efficiency and profitability will be calculated. The project assesses strategies to reduce nitrogen losses, reduce operational expenses while maintaining yields for overall increased profitability.

Examining the impacts of reduced nitrogen rates in a cereal-based rotation with under-sown clover as a cover crop

Coordinating agronomist: Lana Shaw 
Organization: South East Research Farm Inc.
Practices: Cover crops, nitrogen management
Trial started: Spring 2026

Barrier: There is concern about the economic risk of reducing nitrogen fertilizer rates in cereals with under-sown clover.

Description: This trial evaluates reduced nitrogen rates (70% of standard) combined with under-sown clover (red clover) in a rain-fed oat production system. It will assess impacts on nitrogen use efficiency, cereal yield and quality, nitrogen credits from the red clover to the subsequent crop, and the profitability of intercropping, providing practical evidence for adopting these integrated practices.

An economic comparison of different extended grazing strategies

Coordinating agronomists: Serge Pageau and Émilie Blondeau
Organization: Conseil québécois des plantes fourragères
Practices: Cover crops, rotational grazing
Trial started: Fall 2025

Barrier: There is limited local economic and agronomic data to guide farmers on strategies to effectively extend the fall grazing season while reducing labour and feeding costs. Without comprehensive comparisons to conventional confined hay feeding, farmers lack the support needed to make informed decisions about integrating beneficial management practices like grazing cover crops.

Description: This trial compares three late-fall grazing strategies in a cattle operation: stockpiled forage, standing cover crops, and bale grazing on pasture. Forage yield and quality, dry matter intake, and labour requirements will be recorded. The economics of these extended grazing systems will be compared with the established costs and labour associated with the industry-standard practice of feeding stored forage in confinement. Results will help farmers evaluate whether these strategies can improve cost-efficiency and reduce labour, while delivering environmental benefits.