If you got a late start planting your winter annuals, or you got some winterkill and are worried about available forage this spring, now’s the time to shore up your spring green-up plan.
“It’s a tight fit. You've got to be on the ball with it,” said Dave Wilson, a Penn State agronomy Extension educator, during a recent webinar on dairy double cropping.
If you can spare a few acres or can find some extra land to rent this spring, a planting of spring forage oats could help bridge the gap if you think you’ll be short on forage. But get it in early, as soon as the ground is dry enough, Wilson said.
Forage oats yield anywhere from 1.5 to 3.5 tons per acre. The recommended seeding rate is 95 to 130 pounds per acre, with 50 to 80 units of nitrogen fertilizer recommended.
They should be harvested at Feekes growth stage 9 or 10 — the flag leaf, preboot to boot stage — right before the head comes out.
“You want to get the most amount of biomass before the head emerges,” Wilson said.
The flag leaf stage is critical for most annuals as this is the time to start thinking about harvest. Rye, barley, triticale, wheat and spelt will start emerging in mid- to late April in southeast Pennsylvania and points south, and later in New York state and points north.
The earliest to emerge is rye, followed by barley, triticale, wheat and spelt, in that order, Wilson said.
If you have triticale, rye or any other winter annual in the ground, and you need to apply manure this spring, he recommends less than 4,500 gallons per acre. The spring-applied manure can supply about half of the needed nitrogen, as well as phosphorus and potassium.
But applying an extra topdress of commercial nitrogen — 50 units of N — is critical, too, Wilson said, because that nitrogen is more readily available during April and the early part of May when soil temperatures are cold and limit manure N availability. If you don’t apply spring manure, you could apply 80 units of N.
If you don’t have to apply spring manure on your small grains this spring, a topdress N application is still helpful. Heather Karsten, associate professor of crop production and ecology at Penn State, said a six-year study showed 50 pounds of nitrogen on injected fields, or 80 pounds of nitrogen on broadcast fields, helped increase crude protein and neutral detergent fiber levels in rye. The fall manure was applied at 4,500 gallons per acre.
“And the studies we have suggest that the relationships in terms of N response is relevant across winter small grains [rye, triticale and winter wheat], partly because they are based on supplying N for a given dry matter yield,” 2.2 tons dry matter per acre, Karsten said.
“We did not look at spring-applied manure to small grain silages in the studies I discussed. We applied all of the liquid slurry dairy manure in the fall. This is because dairy farms with storage typically have storage limitations for only about six months of manure. So they need to apply about half of their manure in the fall, and the other half is typically applied in spring to corn ground.”
But handle that fall-applied manure with care. Too much fall-applied manure can produce excessive growth and make the crop susceptible to snow mold, Wilson said.
Plan for next fall
While forage will be made in spring and summer, the planning and execution of it really starts the previous fall.
Karsten performed a study where she and other researchers looked at the difference between planting rye in mid-September and applying a later manure application to applying manure first and then coming back and planting rye.
The manure application was 8,000 gallons per acre.
The advantage was clear: Planting early and applying manure later led to better yields, between 21% and 65% better depending on location.
As temperatures and day length decrease, so do the growing conditions, Karsten explained, and experiments in other states showed the same results.
“The impact of these declining temperatures and shorter day length is that you're really taking a big yield penalty by not planting it early,” she said, adding that early establishment of any winter annual also can help reduce pathways for nitrogen losses.
Wilson listed some key practices for annual double cropping:
- Prioritize early planting and have the equipment ready to go.
- Use more than one species to spread out the window of maturing winter annuals at optimum forage quality stage.
- Spread the cut silage in spring and consider tedding to dry more quickly.
- Monitor and maintain potassium as this will get depleted by cuttings.