Tom Kilcer says farmers are missing an opportunity to create greater value from cover crops by using them in a carefully planned winter forage system. He’s promoting a system that gives up some yield in corn silage planted after the winter forage in order to gain overall total yield over a whole growing season.
Kilcer, a longtime Cornell University extension educator who now runs his own consulting company, Advanced Ag Systems, talked about double cropping in northern forage areas at the Canadian Forage and Grasslands Association conference last November in Guelph, Ont.
“Winter forage is cover crops on steroids,” he said.
He listed several advantages of winter forages, including the ability to produce more to fill the popular higher-forage diets for dairy cows, increasing dry matter produced per acre by 25 to 30 per cent and having the ability to harvest quality forage before spring grasses or legumes are ready.
Planting forages in the fall also helps change the timing of spring planting, moving some of the seeding to later in the season.
Not only can the winter forage make up for any difference in planting later-season corn, but subsequent crops showed yield increases. Corn over a three-year average increased in yield by eight to 15 per cent, soybeans were up eight to 15 per cent and nitrate in drainage water was reduced from 21 to 38 per cent. Surface water infiltration increased by seven times.
Those are numbers that are not surprising from other cover crop research, but Kilcer goes further in promoting the value of winter forages as a double crop that pays, producing six to 10 tons of forage per acre.
Treat it like a feed crop
“The first thing you need to understand is we are not growing a cover crop, we’re growing a winter forage,” he said. Kilcer does most of his work with triticale as his winter forage of choice. Use a seed treatment and good seed, he says, as you’re growing a crop you need for feed, not just a cover.
The most important factor is to get the forage crop planted on time. Where Kilcer does most of his work, that’s 10 days to two weeks before winter wheat in the fall.
His research found a 20 per cent increase in yield for forages planted September 9 versus October 5. The key is to get tillering happening before the triticale goes dormant in the late fall. Bonus heat units in the fall and nitrogen are helpful to get that fall tillering.
Fertilizer also had an effect only if the crop was planted early, with a 14 per cent increase in yield to manure if planted in early September, versus no response if planted in October. Be careful top-dressing manure onto the crop too late in the spring. Kilcer told a story of a farmer who did so and the crop ended up being a “slimy, maggoty mess in the bunk.”
There’s no doubt that waiting for the winter forage to come off means planting later corn, and Kilcer says that for every five-day, shorter-season corn that has to be planted, there is a reduction of 1,680 kg/ha of corn silage yield. That usually is offset by the winter forage yield of 4,479 to 8,958 kg/ha.
Rye is a popular cover crop and in some areas it is also used as a winter forage crop, especially on dairy and beef farms, but Kilcer prefers triticale over rye because there’s less chance of triticale lodging in a heavy crop, and triticale’s quality decreases slower than rye.
Winter forage crops like triticale and rye can yield much more than what farmers are used to with alfalfa. They are high-sugar, and need to be laid out wide behind the haybine. Then, he recommends tedding, with ground speed down and RPMs up to get the heavy crop spread out properly. Chop it long, at least 2.5 cm, as it is a high-sugar, high-energy crop. Similar to brown mid-rib corn, winter forage can fall apart fast in the rumen, hence why it should be cut longer.
There’s still a lot to learn about double cropping. There is concern that there’s an alleopathy effect of winter grains on corn that will decrease yield in the next crop. Kilcer is in the middle of a research project looking at this effect, but he says that there are options to strip till or zone till which appears to move the alleopathy effect away from the crop in the strips.
Other crops like alfalfa, red clover and soybeans can be no tilled directly into winter forage stubble, he says.
Kilcer is also looking at other options for double cropping that include dwarf sorghum, grain sorghum and BMR forages.
This article originally appeared in the 2018 Forage & Grassland Guide, produced in partnership by the Canadian Forage & Grassland Association (CFGA) and Glacier FarmMedia LLP and distributed through Country Guide, Canadian Cattlemen and Le Bulletin des agriculteurs. It focuses on forage and grassland issues of importance to crop and livestock producers across Canada.