Using Breeding and Grazing Management to Improve the Winter Hardiness and Persistance of Alfalfa
Project Title
Winter Hardiness Strategies for Alfalfa in Northern Beef Systems
Researchers
Annick Bertrand (AAFC Quebec City) annick.bertrand@agr.gc.ca
Vern Baron (Co-Investigator; AAFC Lacombe), Annie Claessens (AAFC Quebec City), Bill Biligetu (University of Saskatchewan University), Solen Rocher (AAFC Quebec City), Kathleen Glover (AAFC Kentville), and Mary-Cathrine Leewis (AAFC Quebec City)
| Status | Project Code |
|---|---|
| In progress. Results expected in March, 2028 | FRG.08.21C |
Background
This group has been working on breeding alfalfa with reduced fall dormancy and increased yield and winter survival. In the past it was assumed that the yellow-flower alfalfa varieties are most winter hardy but also produce low seed volume making breeding difficult. This group has found that especially in northwestern regions, purple-flower alfalfa varieties are also winter hardy.
Breeding plays a role in how well alfalfa survives winter but so does how it is managed. Management not only effects the alfalfa itself, but also the microbiome of the soil. Very little work has been done looking at how changes to the microbiome affect winter hardiness.
Objectives
- To produce winter-hardy, low-dormant, and grazing-tolerant alfalfa germplasms to extend the grazing and growing season through breeding. To develop new management concepts (alfalfa mixtures and microbiome solutions) to use alfalfa at its full potential across Canada.
What they will do
This project is unique as it is working on both yellow and purple-flower varieties for winter hardiness, fall yield, and persistence. Researchers want to look at both forage breeding and management that will help make alfalfa more stress tolerant.
For the breeding portion, researchers will build on previous results to select new alfalfa varieties for reduced dormancy, higher yield, and increased winter survival. After four years of breeding, they will test new varieties in 4 field trials in Lacombe, Saskatoon, Quebec, and Nappan. Plants will be cut in the establishment year and plant height in the fall will be measured. In the second-year plant survival will be evaluated along with forage biomass and yield. They will also use greenhouse trials to try to isolate the genes responsible for these characteristics to improve future breeding efforts. Throughout the breeding efforts they will also collect seeds and evaluate their microbial communities to determine if winter hardy varieties may recruit more beneficial bacteria and fungi to help them survive.
To look at the grazing management aspect at Nappan and Lacombe, steers dosed with bloat prevention will graze forages 2-3 times per year and this system will be compared to management for hay. Alfalfa production and persistence will be measured, and microbiome analyses will be conducted.
In Quebec and Saskatoon they will evaluate frequent cutting vs. hay systems where the frequent cutting will be done 5 times to weaken plants and facilitate the ability to assess winter survival. Alfalfa production and persistence will be measured, and microbiome analyses will be conducted.
Implications
This project will help to develop alfalfa varieties that are more winter hardy. It will also help us better understand the impacts of management on winter hardiness and long term productivity. The project will identify alfalfa cultivar mixtures providing greater year to year stability than single cultivars under grazing and hay management.