This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the May 2021 issue ofCanadian Cattlemenmagazine and is reprinted on the BCRC Blog with permission of the publisher.
Pasture plants are generally classified as decreasers, increasers and invaders. Decreaser species are the plants you want to see and your cattle prefer to eat, so they face the most grazing pressure. Increaser plants tend to thrive when the decreaser species are challenged by overgrazing, drought or other sub-optimal conditions. Invaders (weeds) proliferate when increasers and the remaining decreasers are so weakened by overgrazing or environmental extremes that they have a hard time competing for nutrients, water and sunlight.
Healthy, productive pastures are dominated by decreasers. The composition of the decreaser community in healthy native rangelands was shaped by thousands of years of natural selection and environmental pressures. In tame pastures, humans take the wheel from Mother Nature as we seek to establish and maintain a stand of tame decreaser species that can be productive and long-lived in our particular soil and climate conditions. In both native and tame pastures, good grazing managers adjust stocking densities, grazing intensities, grazing and rest period length and frequency, etc. based on annual and seasonal variations in growing conditions to maintain pasture health and optimize long-term forage and animal productivity. Continue reading →
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the May 2019 issue ofCanadian Cattlemenmagazine and is reprinted on the BCRC Blog with permission of the publisher.
Photo credit to Agriculture Agri-Food Canada
Forage legumes provide high yields, protein, and good animal performance while improving soil fertility by fixing nitrogen from the air. Alfalfa is the highest yielding and most widely-used legume but can cause bloat. Legumes like cicer milkvetch, sainfoin and birdsfoot trefoil do not cause bloat. As little as 25% sainfoin in a pasture can virtually eliminate the risk of bloat even if the other 75% is alfalfa.
The problem is that older sainfoin varieties don’t regrow as fast as alfalfa after grazing. Alfalfa’s aggressive nature allows it to outcompete sainfoin for sunlight, moisture and nutrients. Without careful grazing management, sainfoin can disappear from a pasture in a few years. This might be because plant breeders have traditionally selected new varieties for clipped forage yield under monoculture conditions. This doesn’t reflect the challenges sainfoin faces when grown with alfalfa and grazed.