After a dry season “drought proofing” feed is a hot topic during this year’s round of winter livestock seminars.
After last year’s headline-making dry weather left many with half or less of their normal hay, prematurely dried-out dugouts, triggered herd culling, the message is finding an interested audience.
Speakers, meanwhile, are hitting largely on the same points as they take the podium at events ranging from Manitoba Agriculture’s Beef and Forage Days to Ag Days.
Why it matters: Producers may want to spend more time on drought planning after last year’s short hay harvest and to avoid a similar scramble for feed in future years.
Pasture management alone may add some drought buffer, provincial livestock specialist Tim Clarke said during his session at Ag Days 2019. Every clipping requires the plant to borrow carbohydrates from the roots to recover, he said, and a pasture that ends the season clipped down to the average height of a golf green may have little resiliency when dry weather comes. Instead, he argued, the litter left over from uneaten forage is likely paying larger dividends to the soil and future capacity of pasture, and cattle should leave behind half the available feed.
“We don’t lose this grass because it’s left over at the end of the season,” he said.
Managed grazing, he argued, may add a yield boost on top of impacts to the soil, with increased root growth decomposing into greater organic matter and improving soil structure, soil fertility and drawing down more water into the soil, a reservoir those plants can then draw on when rains turn off.
Clarke turned to Manitoba trials comparing continuous grazing, rotational grazing, and rotational grazing with an added 50 to 100 pounds per acre of nitrogen, a nutrient that he argues many pastures are deficient in.
The trial found that adding in three rotationally grazed, 80-acre paddocks jump-started forage production from 943 to 2,462 pounds of dry matter, numbers that increased even further to 4,029 pounds an acre with an extra 50 pounds of fertilizer.
The pitch for rotational grazing is not new. This year, a project comparing rotational and continuous grazing at Manitoba Beef and Forage Initiatives kept cattle on rotationally grazed paddocks for weeks longer than the continuously grazed pasture across the fenceline.
Jane Thornton, provincial livestock specialist in southwest Manitoba, put field litter at the top of her own drought-proofing priorities.
“If you remove 90 per cent of the forage, you’re only leaving 10 per cent behind and I’ve gone to pastures and taken the litter off and I’m not even collecting 160 pounds per acre,” she said. “Well, that’s the equivalent of taking three 50-pound bales out and spreading it out over an acre. That’s not very much residue. That residue is so important in terms of not letting the soil heat up as much and protecting the moisture that falls and not letting it run off.”
Bruce Anderson of the University of Nebraska also highlighted rotational grazing and boosting pasture with nitrogen, along with a pitch for added legumes in pasture and filling in feed gaps with annual forages.
Anderson’s trials have noted that pastures seeded with legumes were more productive late in the season as grasses matured and feed values fell.
“I certainly think that if you do have interest in putting in legumes, this is a time to be looking at doing that — unless we get some real strong forecasts that say, ‘yes, it’s going to be dry again,’ and then you might not be real successful,” he said, noting there will be less establishment competition this year as grasses are stressed. “I think another thing that we have to recognize is, especially if we really excessively grazed the pastures last summer when it was dry, knowing that those plants are going to be less vigorous, producers really should kind of be conservative in terms of how soon they turn out on those pastures.”
Looking past hay
Manitoba Agriculture has also urged producers to look past hay in their drought plans.
Warm-season annuals could be a “knee-jerk reaction,” to short feed, Clarke said, while mixing cold- and warm-season annuals in a greenfeed may help hedge bets on weather.
“Sometimes people in our country, they’ll mix a cool-season grass and a warm-season grass just because, if you have a droughty situation, the warm-season grass will be more prevalent in the greenfeed sward than the cool-season grass,” he said.
The reverse will be true in a cool, wet year, he added, with the cool-season species taking the lead.
Corn, meanwhile, shouldn’t be discounted in a short forage year given its ability to produce large amounts of feed on few acres, he added.
Both corn and cereal silage also rate higher water use efficiency compared to perennial grasses, alfalfa or regular grain. Manitoba Agriculture estimates that it takes 84 millimetres of moisture per tonne of corn silage and 93 millimetres per tonne of cereal silage.
Clarke also argues that producers should look for chances to integrate nitrogen-fixing legumes, although they should not be counting on a sudden boost in feed production after a single year of planting alfalfa.
Producers looking to boost legumes while already in a dry stretch may also be setting themselves up for a challenge.
Thornton’s own trials pasture seeding legumes found little establishment in the dry conditions near Brandon last year.
According to Manitoba Agriculture, alfalfa takes 170 millimetres of moisture per tonne of production, compared to annual cereal crops, which hover around 100 millimetres per tonne.
Thornton instead cited legumes as a long-term drought solution, to come into the fore if already established when the dry weather hits.
“For many areas here in Manitoba, we have a high water table, so if you put in taproot alfalfa, that’s great, because your grass forages will go dormant but your legumes will still be able to suck moisture,” she said.
Producers should be thinking in the long term in general when they plan for drought, Clarke also warned.
“This is not a one-year thing,” he cautioned. “This is like a three- to five- to seven-year payback, so plan for it.”