Development of Native and Tame Forage Varieties and Mixtures for Improved Forage and Environmental Productivity and Resilience

Background

This project was a collaborative effort between many researchers who are studying topics related to the use and development of native and tame forages for beef production. The funding from this Beef Cluster project was used to improve forage resources and document how different forages contribute to the forage and beef sector, not only in regards to forage production and nutrition, but also through ecosystem services such as soil carbon sequestration. These issues are important to the industry as efforts are made to implement practices that are more resilient to climate change while maintaining production potential. Through this project, with the combination of plant material development and plant mixtures and community development, we sought to increase forage production and stand stability, and enhance plant biodiversity and sustainability in forage-based grazing systems. 

Objectives

• Objective 1: Forage breeding: A) Tame forages: Evaluate and develop new varieties of meadow brome, orchardgrass, and tall fescue; B) Native forages: Continued advancement of native plant materials 
• Objective 2: Alfalfa Breeding: Genomic prediction of alfalfa germplasm for high yield, regrowth, and quality using Genotyping by Sequencing (GBS) 
• Objective 3: Plant ecology and soil microbiology: A) Assessment of diversification of existing and newly seeded plant mixtures; B) Provide scientific data regarding soil carbon sequestration and soil biodiversity benefits 
• Objective 4: Long-term evaluation of native plant mixtures; Long-term evaluation of sainfoin-grass mixes under two harvest frequencies 

What They Did

Objective 1: A) For the tame forages, diverse germplasm of meadow brome, orchardgrass, and tall fescue were evaluated for grazing characteristics such as regrowth, persistence, yield, and quality across 4-5 different sites, and new populations were developed. B) For the native forages, this project continued to evaluate native grasses, legumes, and shrubs including prairie sandreed, white and purple prairie clovers, winterfat, side oats grama, plains rough fescue, northern wheatgrass, among others, for forage yield, seed production, and quality. Seed was increased for several native species.  

Objective 2: Genomic selection, an advanced molecular breeding method, was incorporated into current alfalfa breeding efforts to reduce breeding time and increase genetic gain for forage yield and other important traits.   

Objective 3: A) Flowering forbs (e.g., purple prairie clover, perennial blue flax, yarrow, gaillardia) were added to existing plant communities to observe the effect of these plants on soil microbial diversity and pollinator visitation. New plots were established at the same time to assess the contribution of forbs to soil and forage. B) Soil carbon was assessed under long-term native plant plots to look for changes in soil carbon over time and to look for differences between plots of varying plant composition. 

Objective 4: We continued to collect yield and quality data from a sainfoin-grass (hybrid brome, meadow brome, and crested wheatgrass) binary mixture trial that was initiated in 2015 at Swift Current, Saskatoon, and Brandon. We also continued to monitor native perennial trials seeded at Lethbridge, Swift Current, and Brandon for species composition and production over time. 

What They Learned

Novel breeding materials were developed for meadow brome, tall fescue, and alfalfa, which will result in improved forage varieties with increased yield potential and improved nutritional profiles. Native forages continue to be assessed for adaptation and performance characteristics. The greatest challenge in this work has been identifying seed sources adapted to Western Canada for population development. Dr. Sean Asselin (a new forage breeder at Swift Current Research & Development Center, AAFC) is working with Plant Genetic Resources Canada, the United States Department of Agriculture, and native seed producers to identify suitable germplasm sourced from Western Canada for cultivar development.  

We continue to gather more information on soil carbon under various diverse native plant mixtures. While grasslands are known to be excellent at storing carbon, our project showed no evidence of differences in soil carbon with respect to varying plant species composition. Treatments also did not have a significant effect on enzyme activity (an indicator of soil microbe activity cycling nutrients). Forbs added to existing or new native plant plots struggled to establish and as such, their minimal presence did not change soil carbon levels or increase pollinator visitation. 

In regards to long-term monitoring of existing field trials, the forage yield of sainfoin in binary mixtures was similar when we reduced the seeding rate to 15LB/ac from 30LB/ac. A full-year of rest increased sainfoin percentages in all grass-sainfoin mixtures. Native mixtures that were seeded in 2010 and 2014 were susceptible to invasion by tame perennial forages and other weeds, and many seeded species diminished in production potential (prairie clovers, bluebunch wheatgrass) when seeded in mixtures with competitive grasses such as western wheatgrass.

What It Means

Many new forage breeding populations have been developed for tame and native forage species, and further work in larger-scale field trials needs to occur before variety registration. We have begun re-building the capacity for native forage cultivar development and building relationships with the Canadian Seed Growers Association and native forage seed producers to improve seed availability and bring new and improved materials to market. Genomic selection is a novel tool that could potentially accelerate alfalfa breeding. Agronomic and ecological knowledge of sainfoin-grass mixtures and native plant mixtures could provide guidelines for forage mixture selection, but it is unclear how these specific mixtures will improve soil carbon storage.