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Lessons Learned from a Kernza Field Day

The South Kinni Farmer-Led Watershed Council hosted a pre-harvest field day in early July for farmers in the area to see council lead farmer, Brad Peterson’s, Kernza field. While Kernza is one piece of many potential solutions to improve water quality and climate resilience in agriculture and diversify farmer revenue opportunities, there are many lessons to be learned to make this a viable crop for farmers. This field day helped answer a couple of those questions. 

Four people stand in a Kernza field.
Leaders from the South Kinnickinnic Farmer-Led Watershed Council are outstanding in their field. This time, they were out standing in Peterson’s field examining the Kernza crop before harvest. 

What is Kernza

Kernza is sometimes referred to as perennial grain. It is a grass that can be planted once and harvested 3 times for grain and even more times for feedstock. This is attractive as it reduces the passes over the field year over year, saving farmer time and labor, while also providing soil health protection with an immense root system that ends up reaching down 12 to 13 feet. 


Kernza yields are currently much lower than traditional wheat yields, but growing quickly. Since research on the plant started, the seed size has doubled. This new crop is usually grown in relatively small fields of one to three acres for speciality production around urban hubs like Madison with the largest field known right now being 60 acres in Minnesota. 


“There are over 50 products made with Kernza on the market right now,” said Steffen Mirskey, UW Extension Speciality Crop Specialist. Kernza products available include beers, breads, and other baked goods.

A Kernza field with a blue sky.
The yield potential of Kernza is rapidly increasing according to The Land Institute which has been working on a breeding program for the crop since 2003.

Early Lessons Growing Kernza

Kernza is a relatively low-nitrogen grass with a recommended N rate of 70 to 90 pounds per acre annually based on recommendations from the University of Minnesota. This research coming out of a university close to our latitude gives extra confidence to farmers. One immediate lesson Peterson learned is that if you apply more than this, you’ll end up with a very tall crop. It can be used with 2-4D and Curtail to assist with weed control. 




Peterson planted 50 acres of Kernza under contract. After planting last fall, they didn’t see rain for 2 months, so they did a supplemental planting this spring to improve the stand. One 20 acre stand had such poor growth this spring that they chose to terminate and instead plant more traditional crops. They kept 30 acres in Kernza, however, to learn some lessons with the crop. 


He had some nerves earlier this summer when he checked the crop only to find a lot of volunteer wheat had emerged even though it had been over two years since wheat had been planted in the field. However, checking in with his contractors, and monitoring the field through the summer, what appeared to be a big concern at first is now significantly less. The wheat remains at a different height and has been outcompeted by the Kernza plants which have come into their own since early summer. 


Kernza pictured with roots attached.
Many of Kernza’s main environmental benefits and hardiness come from it’s robust root mass which will only get bigger over the next two years. These roots will absorb carbon, improve soil texture, and reduce field erosion while improving rainwater infiltration. 

Like other small grains, the Kernza will be harvested in late July or early August. Stalks will be taken for straw and then a hay crop from the re-growth this fall. Mirsky noted that studies show a high relative forage quality of 150 through early research. This is a side benefit to Peterson, a dairy farmer. 


And without having to plant again next year, Peterson can expect to get the same three harvests next year, with this first year the grain will have its highest yield. The third year of growth tends to see the least amount of harvestable grain, as the Kernza begins to outcompete against itself. 


Attendees of the field day noted that the third year harvest could be improved with disturbance to the crop in the fall of the second year to reduce that competition. Peterson is considering knifing in a manure application to see if that helps. Other attendees suggested heavy grazing of the field as an option. 


Processing Kernza

As with any new crop, the supply chain development in conjunction with learning to grow the crop is a challenge. Mirsky noted that there is only one processor of the grain in Wisconsin. There are two more in Minnesota; all are roughly equal distances from Peterson’s field in western Wisconsin. 


Most of the folks growing Kernza are getting a certification called Perennial Percent through the Land Institute, and/or Regenerative Organic Certification (ROC) to communicate to buyers, processors, and consumers the positive impact of the crop. 


One neighboring farmer on the South Kinni Farmer-Led Council, Maureen Ash, is quite familiar with Kernza. She had a local bakery and used up to 40% of her grain mix in her sourdough in the past, saying that the grain “added depth to the flavor of the bread.” Having milled the grain herself in previous years, Ash was delighted to see a full field of the crop almost ready to go to harvest.

Four people stand in a Kernza field.
Steffen Mirskey (right front) speaks with baker, Maureen Ash (left front), in Peterson’s Kernza field in early July. 


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