Plant diversity is key to pasture management

Plant diversity plays a significant role in flourishing pastures.

Diverse forage stands offer numerous advantages, including having plants able to withstand different weather and soil conditions, says Jane Thornton, Manitoba Agriculture forage and pasture specialist.

That adaptation will mitigate against drought and flood, as well as hot and cool conditions, she says.

Here’s how to successfully weave forage diversity and pasture management together. Tweet this

Year-round

Diversity also provides plants that are available for grazing at different times of the year, Thornton says.

“When you pair species like orchard grass – a quick spring starter – and tall fescue – which will push growth deep into the fall – with a productive legume, you spread your production throughout the entire season,” explains Cedric MacLeod, executive director of Canadian Forage and Grassland Association.

Diversity

Mixtures of grasses and legumes are common in Ontario, says the province’s forage and grazing specialist, Christine O’Reilly.

She says forage mixtures should be selected to suit the soil — taking into account drainage, pH, and fertility — climate and management conditions where they will be grown.

Thornton notes that in tame forages, some species have a high degree of adaptation and will crowd out other species. That may not do well if the weather changes and could lead to the emergence of weeds.

Legumes

When he’s designing mixes for tame, reseeded pastures, MacLeod encourages producers to start out with at least 50 to 60 per cent legumes, knowing that level will diminish over time, and should not be allowed to drop below 30 per cent.

Among the benefits of legumes is their adding nitrogen to soil, which improves yield compared to unfertilized grasses alone, O’Reilly says. They’re also drought tolerant.

“Common forage legumes in Ontario tend to have deep taproots, and so can reach water during dry spells that grasses may not have access to,” O’Reilly says.

They don’t, however, stand up well to flooding, although MacLeod notes there’s a rhizomatous alfalfa that’s been bred in the Maritimes to help make legumes there more resilient to the region’s wet conditions. The introduction of branch rooted varieties has also increased resilience.

Livestock

Legumes also contain higher protein than grasses, which can help meet the dietary requirements of growing or lactating livestock, O’Reilly says.

To maintain 30 per cent legumes in a stand at all times, farmers need to prevent overgrazing to give their pastures rest, MacLeod says.

Animals seek the tastiest plants, and without a rotational grazing program, they’ll graze them down to a point from which they can’t recover.

“We can push pasture productivity anywhere from 20 to 75 per cent if we use some sort of rotational grazing,” MacLeod says.

Bottom line

Forage diversity, such as a mixture of grasses and legumes, and pasture management, such as combining fast-growing and long-growing grasses, are key strategies in creating robust pastures.

Article by: Richard Kamchen