Perennials are a big complement to annual crops
Plant a seed every five years or more, yet fill the grain bins every year. Shake off herbicide and pesticide inputs, yet maintain a robust crop. Are perennial crops the promise of tomorrow’s agriculture or a tantalizing prize forever hidden around the bend? Researchers are ripping fresh ground with new breeding tools, and viable perennial crops might be closer than many farmers suspect.
In farming’s version of the tortoise and hare, could perennials outperform annuals over the long term? Don Wyse, a professor of agronomy and plant genetics at the University of Minnesota, believes plant breeders can select perennials to outperform annual wheat and barley because of the massive window for solar energy collection. “Only time will tell, but that’s what our research program is focused on,” Wyse says.
Wyse is measuring the input amount of a perennial versus annual system and using Kernza, an intermediate wheat grass as the grain model. His Kernza breeding project is in partnership with Lee DeHaan of The Land Institute in Salina, Kan.
Kernza has an extensive root system stretching 10' down, vital for hillside growth where annual grain crops are subject to erosion. Kernza’s root system is capable of a high rate of nitrogen uptake. Sitting in a field, Kernza looks like a pasture waiting to be grazed. It has the potential to function differently from previous grain crops.
Kernza is seeded in fall and its early growth and dense development smother weeds. Insect and disease management aren’t necessary either, Wyse adds. Breeders have experimented with wheat–Kernza crosses, attempting to transfer Kernza’s high threshold for disease resistance into wheat.
“We haven’t seen any major signs of disease problems. That doesn’t mean it won’t happen because time and presence could make a difference,” Wyse says. Essentially, his research has shown no need for herbicides, insecticides or fungicides. What is necessary? Seed, planting, harvest and nitrogen in the range of 60 lb. to 70 lb.
Harvested in early fall, Kernza grain is one-third the size of wheat grain and is cut with a standard combine. It produces one crop every year but allows producers an extra grazing option. After cutting, Kernza gains several tons of regrowth during the fall, which serve as a food source for livestock. Wyse believes there is strong opportunity for a Kernza grain and forage system in the upper Midwest.
The window between planting and reseeding is roughly five years. Wyse’s oldest Kernza was planted six years ago and still produces seed. Yields range from 30% to 50% of wheat. Yield consistency is an issue, and the mechanics of Kernza yield remain an open question. The University of Minnesota’s breeding program is in the early stages of the third cycle of selection. “We’ll soon have a wider selection of germplasm to look at,” Wyse says.
In northern Minnesota, Kernza is grown commercially on contract with Patagonia. Three Roseau County growers, including Richard Magnusson, are trying Kernza for the first time. Magnusson farms 60 miles east of the Minnesota-North Dakota line and 8 miles south of the Canadian border. He grows corn, soybeans, wheat, sunflower, lawn grass for seed, forage for seed, barley, field peas, oats, Kentucky bluegrass—and now Kernza.
There is strong opportunity for a Kernza grain and forage system in the upper Midwest, says Don Wyse, University of Minnesota.
“I grow Kernza using organic production methods. If you grow Kernza conventionally, you’ll still pay for far less inputs, but it does need a considerable amount of nitrogen,” he says.
Spread over 35 acres, Magnusson planted Kernza in fall 2014 (late August and early September), with the same air drills he uses for wheat. Perennials seed shallow and moisture is critical. Kernza is aggressive coming out of the ground, Magnusson notes. “It’ll be three weeks before you can spot Kentucky bluegrass. Kernza takes 10 days,” he says. “We have plenty of rain and don’t need to irrigate.”
After planting, Kernza requires little care. It is competitive with weeds and doesn’t seem to have any insect or disease problems, Magnusson adds. Typically by Nov. 1, his ground is frozen and Kernza is dormant. “We harvested about Aug. 1. We swathed and left it in a windrow for a week to dry,” he says.
Yield was 400 lb. to 700 lb. per acre. After combining, Magnusson had a neighbor bale the straw for cattle feed.
Magnusson faces his first frost in September and his last frost in May—a tight planting window. Kernza is ideal for reducing risks of a short planting season, but still has challenges. “The market is only just beginning,” he says. “Growers will need customers.”
Kernza doesn’t contain gluten levels comparable to wheat and can’t sit well by itself in a raised-bread system. Small molecules mean it needs to function as a 50-50 mix with wheat flower. However, it can be used solo in baking products. The big market issue is developing best end-uses for the grain.
Kernza produces one crop every year but allows farmers a grazing option.
Wyse is also trialing hazelnut, silphium (native oilseed), perennial flax and perennial sunflowers. As co-director of The Center for Integrated Natural Resources & Agricultural Management’s Forever Green Initiative, he is involved in many perennial-crop research projects. For example, he is testing camelina and pennycress as winter annuals to complement a classic corn-soy rotation.
Hazelnut is a native tree packed with promise, he adds. It already has a network of activity reliant on tree production and infrastructure. While hazelnut has never been developed as an industry, it produces oil similar in grade to olive oil. “The market is there and companies such as General Mills are ready to contract for a lot of hazelnut production,” Wyse notes.
Perennials are already highly efficient from an environmental perspective and will be efficient from a production perspective in the near future, he says.
“Historically, as we developed crops, we only paid attention to yield,” Wyse adds. “Now we’ve got a path to breed crops to allow farmers to maintain or enhance production and reduce input costs, all the while protecting water and soil.”