Caroline Halde and Marie-Noëlle Thivierge, along with their team, are investigating current and innovative practices on commercial organic dairy farms and at research facilities to assess soil health, carbon storage, and plant resilience in relation to pasture management. They will survey Ontario and Quebec organic dairy producers about their current pasture management practices, assess soil health and carbon stocks in pastures, and test promising forage mixtures for agronomic performance, resilience to climate disturbance, and capacity to mitigate greenhouse gas emissions. Grazing management strategies will be compared, assessing cow grazing behaviour, health, and productivity. Forage mixtures will also be assessed for grazing preference, nitrogen use efficiency, and enteric methane emissions in lactating dairy cows.
Research Objectives
- Characterize pasture management strategies commonly used in organic dairy production to identify those with the best potential for resilience and productivity.
- Characterize soil health and surface carbon storage on selected organic farms to establish a relationship between pasture management strategies, soil health, and soil carbon storage.
- Assess multispecies forage mixtures agronomic performance and resilience and capacity to mitigate greenhouse gas emissions through carbon-input under field conditions and at the whole-farm level using modelling.
- Evaluate, under controlled conditions, pasture management strategies to measure their effects on cow grazing behaviour, health and productivity.
- Evaluate the nitrogen excretion (in feces and urine) and efficiency (milk N/diet N), and the enteric methane emission of lactating dairy cows fed different multispecies forage mixtures.
Progress and Results
Research Update (March 2026)
KEY TAKEAWAYS (PRELIMINARY OBSERVATIONS)
- The survey of organic dairy producers in Ontario and Quebec is complete.
- Soil samples were collected from nine organic dairy farms. Soil health and carbon stock reports were shared with participating farmers.
- Field trials at two sites demonstrated that multispecies forage mixtures, particularly the six-species mixture, produced higher forage yields than pure stands. Combining legume and grass species and increasing species diversity improved productivity while reducing weed pressure.
- Several key analyses – and whole farm modelling – have been compromised by AAFC site closures and workforce reallocation.
- The effects of pasture management on cow behaviour, health and productivity were investigated.
Research Update (March 2025)
KEY TAKEAWAYS (PRELIMINARY OBSERVATIONS)
- Researchers expanded an existing survey of organic dairy farmers in Ontario. Their goal was to survey approximately 35% of organic producers in Ontario and Quebec.
- Researchers selected eleven organic dairy farms to evaluate the impact of pasture management on soil health and soil carbon storage.
- The field experiment comprising 55 plant communities (pure species and mixtures from 2 to 10 species) was established at two AAFC sites (Normandin and Saint-Augustin-de-Desmaures) and at McGill University. Preliminary results from the Saint-Augustin site are noted in the full report (PDF).
- Researchers at the University of Guelph monitored cow voluntary intake and preference for various freshly-cut forage species.
Additional Links and Resources
Background Information
From the research activity proposal:
The overall goal of the project is to study the impacts of various strategies to improve the resilience and greenhouse gas mitigation potential of pasture systems for dairy cows, on the productivity and health of soils, plants and animals. The research will be conducted in five studies, two collecting data from commercial organic dairy farms, and three from research farms.
Study 1 will focus on current practices on organic dairy farms in Ontario and Quebec. Producers will be surveyed on their pasture management practices, including their choices of forage species and mixtures, grazing systems, herbage allowance, etc. Results from this large survey will be discussed with an advisory committee and will help inform further studies.
A sub-sample of these farms will be visited in Study 2, which will focus on soil health and its relation to pasture management practices. From the results of Study 1 and through a participative approach with researchers, stakeholders, and farmers, promising forage mixtures will be selected and tested under field conditions at two sites and over three growing seasons (Study 3) to measure their yield, nutritive value, root biomass, and their effect on soil C and N stocks, and microbial community structure. One additional site will further study forage mixtures resilience to climate disturbance by subjecting them to two subsequent drought episodes through rain-out shelters, and economic, agronomic and environmental performance will be modelled at the whole-farm level.
Grazing management strategies will be selected from Study 1, and tested on organic dairy cows, to determine their effects on cow grazing behaviour, health, and productivity. Preference tests will also be conducted on the promising forage mixtures to determine their palatability (Study 4).
Finally, we will evaluate the nitrogen excretion (in feces and urine) and efficiency (milk N/diet N), as well as enteric methane emission of lactating dairy cows fed resilient forages (Study 5).
This research is aligned with all three federal Agriscience Renewal priority areas, as it aims to document C sequestration/GHG mitigation associated with pasture systems (Climate and Environment), to improve pasture and animal productivity with the selection of resilient forage mixtures and grazing strategies (Economic Growth), as well as to enhance soil health, animal welfare, climate change adaptation of pasture systems (Resilience). The research also addresses three of the Organic Cluster Overarching Priorities, improving economic resilience and environmental performance of forage systems, while enhancing animal welfare and public trust in the dairy sector. The study will provide organic dairy farmers with practical management strategies that will be easily applicable in the short term.
Contributing Partners
Meet the Research Team
Caroline Halde, agr., Ph. D.
Caroline Halde is an Associate Professor of organic agriculture and agroecology at Université Laval. Dr. Halde grew up on an organic dairy and grain farm in Quebec. She leads the Agroecology Lab at Université Laval, a dynamic team of about fifteen students and research technicians with multidisciplinary interests in field crop and forage agronomy, cover crops and soil health. She has contributed to the establishment of a Graduate Microprogram in Agroecology, newly offered at Université Laval. She is actively involved in provincial and national committees aiming to develop and support the organic agriculture sector.
Marie-Noëlle Thivierge, agr., Ph. D.
Marie-Noëlle Thivierge is a research scientist with Agriculture and Agri-Food Canada working at the Quebec Research and Development Centre since 2015. Her research activities are aimed at deepening our understanding of forage systems and their associated ecosystem services, as well as improving cropping practices to promote resilience and adaptation to climate change. Over the years, she has led or participated in several research projects focusing on crop rotations and forage mixtures. A large part of her research program is devoted to the study of plant root traits in relation to carbon sequestration, soil health, and resilience.
Activity 16 Research Team
Name | Affiliation |
|---|---|
Renée Bergeron | University of Guelph |
Édith Charbonneau | Université Laval |
Elsa Vasseur | McGill University |
Philippe Seguin | McGill University |
Nicolas Devillers | Agriculture and Agri-Food Canada |
Julie Lajeunesse | Agriculture and Agri-Food Canada |
Fadi Hassanat | Agriculture and Agri-Food Canada |
Jonathan Lafond | Université Laval |
Jean-Thomas Denault | Agriculture and Agri-Food Canada |
Mary-Cathrine Leewis | Agriculture and Agri-Food Canada |
We asked Caroline Halde
What got you interested in this research project?
I grew up on an organic dairy farm in Quebec. I have long been interested in the ability of organic dairy farms to cope with climate change. This project aims to identify strategies to improve the climate change mitigation potential and the resilience of grazing systems on organic dairy farms. This is a project that will lead to concrete benefits for these farms.
Where is your research taking place?
Our research will take place on organic dairy farms and research stations in Quebec and in Ontario.
What drew you to organic agriculture research?
Growing up, I worked on the family organic farm where there were always several trials or research projects going on. Agronomists, technicians, and researchers often came to sample our fields or organize field days at our farm. This introduced me very early to experiments in the field and the dairy barn. My first experiences in academic research were during my bachelor’s degree, with projects relating to the organic production of tomatoes and in greenhouses (with Drs Martine Dorais and Steeve Pepin) and the emission of greenhouse gases (with Dr Suzanne Allaire). Subsequently, continuing my career in organic agriculture research was obvious. This led me to pursue my Master’s degree in pastures (with Dr. Ralph C. Martin at Dalhousie University) and in organic no-till grain cropping systems (with Dr. Martin Entz at the University of Manitoba).
How are you encouraging or training the next generation of scientists?
My research team offers an open, inclusive learning environment, where everything can be questioned: from the dominant economic model to the processes of formation and stabilization of organic matter in soils, nothing is off limits! I also try to allow the students under my supervision to develop a network of collaborators. In the graduate courses that I teach, I use flipped classroom teaching to offer greater autonomy in learning.
Outside of your research pursuits, what is an activity you enjoy doing in your free time?
In my free time, I enjoy baking and doing crafts with my daughter. I also like to play guitar and read comics and poetry.
