As I was writing this column, there were two days left of winter. It was a milder than usual cold weather season. I only used the snowblower once. A gift from my three sons 15 winters ago, it’s seen lots of use other years.
In any case, the winter forages and grasses are kicking into gear. Up till 12 growing seasons ago, I’d never used (nor heard) the term “winter forage.” In 2012 (a bad drought year), I visited Cornell Valatie Research Farm as a guest of Tom Kilcer, a Certified Crop Advisor, whom I had known for years. His first year as Cooperative Extension agent was 1977-78, and it overlapped with my last in that vocation.
When he showed me immature stands of wheat, rye and triticale 12 years ago, I told him, “Those must be your cover crops.” He responded, “No, I call them winter forages. I don’t call them cover crops – and neither should you!”
Tapping into Kilcer’s current online newsletter at advancedagsys.com, I read his March 2024 edition titled “Optimizing Winter Forage Quality and Quantity.” He wrote that this is a year where you can move rapidly, getting a jump on the season. Enormous amounts of spring growth on winter forages demand sufficient nitrogen (N) and sulfur (S) to optimize yield and, especially, quality. Many factors help determine the best N rate to apply in spring. Recommended rates can vary significantly.
Kilcer wrote that the most important of these factors is when the crop was planted in the particular grower’s climatic region. If it goes into winter with three to four inches of autumn growth, and soil is visible between the rows, you can expect 1.75 to 2.25 tons of whole forage dry matter. A target of 20% crude protein points to a top-dress of 125 lbs. of N plus 22 lbs. of S.
If it is smaller with just individual spikes of green, he recommended, “Save your money and plant the next crop (in the rotation, come spring).” However, if you plant on time so that crops enter winter seven to 10 inches tall, with solid cover – no ground showing between rows – there are two major benefits.
First, your spring yield potential could be 3.5 – 4 tons of forage dry matter/acre. Secondly, Dr. Quirine Kettering’s research at Cornell – combined with Kilcer’s research at Valatie – found that autumn growth is 22% crude protein. That seven- to 10-inch height represents 1 – 1.5 tons of dry matter containing 65 – 105 lbs. of N.
This is because the excess manure applied the previous spring – before corn had sufficient organic matter to release N after corn harvest – was captured by on-time, around Labor Day planting. This N kicks in as triticale approaches winter. In Northeast conditions without manure, spring yields increased, in keeping with greater amounts of autumn N that had been applied to on-time planted triticale. Spring yields increased when up to 60 lbs. N (plus 10 lbs. S) were applied at autumn planting.
Kilcer pointed out that for farmers farther south, higher autumn N application rates may be justified. He stressed, “Do NOT delay triticale planting to apply fall manure nitrogen – you lose more yield than you gain in nitrogen, based on mine and Penn State research.”
Under these high yield conditions, 3.5 tons of spring yield at 20% crude protein contains 225 lbs. of N. If 60 lbs. were applied and taken up in autumn, you would still need 165 lbs. N – plus 26 lbs. S applied in spring – to make N uptake very efficient. Four tons of dry matter spring yield, at 20% crude protein, contains 260 lbs. N.
The same above calculations are needed to determine what to apply, but autumn uptake may be closer to 100 lbs. of N/acre. He’s assuming that protein is 16.25% N – check the math.
He noted that with rye, all bets are off. When they applied N to support these high crude protein levels, most of the crop lodged. The above suggestions are for winter triticale, which is shorter and denser than rye, and can be expected to produce superior crude protein while still standing.
Keep in mind that most N applied, beyond what is needed for the winter forage crop, will remain for the next crop to get off a quick start. This form of continuous cropping is a very efficient N utilization system. The recommended fertilizer mix for cool season grasses, winter triticale forages and any other crop needing S is 500 lbs. of ammonium sulfate and 1,500 lbs. of urea with an anti-volatilization agent. The latter is critical as winter forages and grasses have an enzyme that rapidly splits the urea into volatilized ammonia gas.
One hundred lbs. of this mix provide 38 lbs. of N and 6 lbs. of S. Untreated urea lost 63% more than treated urea in side-by-side replicated trials. If applying liquid N, a significant portion is in the ammonia form and an anti-volatilization compound will still increase the return on the N investment. A minimum of 1 part S (in sulfate form) to 10 parts N is still suggested in the liquid fertilizer.
For those new to this crop (as there are increasingly more winter forage novices), these folks happily accept both the very high-quality roughage attainable as well as the 35% yield increase from double cropping that’s becoming commonplace. Regarding harvest timing, Kilcer pointed out that a week earlier planting in autumn gains three days earlier harvest in spring. South-facing well-drained soils will be ready sooner than north-facing poorer drained fields. Growers open harvest windows further by planting an early maturing variety first and a later maturity variety later – a practice most corn growers have perfected.
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