Kernza® and Intermediate Wheatgrass: The Plant That Keeps on Giving

Peter Kleinman is a soil scientist and research leader at the ARS Soil Management and Sugarbeet Research Unit in Ft. Collins, CO.

Welcome Dr. Kleinman to Under the Microscope.

UM: What is intermediate wheatgrass and why is ARS studying this crop?

PK: Intermediate wheatgrass is a remarkable grain and forage crop that is perennial, meaning that it continues to grow after its first year of establishment, and so doesn't need to be replanted each year. Perennial crops offer a wealth of potential benefits to consumers, the environment, and farmers, so there has been a great deal of interest in finding perennial versions of some of our most important crops, like grains.

As a new crop, intermediate wheatgrass offers all kinds of opportunities to understand the interactions between breeding and environmental and management variables in ways that have been lost in other, established crops. This fundamental science requires long-term research to develop, something that USDA's programs are uniquely suited to carry out. We can look across America's production systems and learn what we need to successfully integrate a perennial grain into systems that have historically been built around annual grains. This system-level study is essential to understanding what we need to have in place to make perennial agriculture a reality.

UM: How is Kernza® related to intermediate wheatgrass?

PK: Kernza is the registered trade name owned by The Land Institute for some of the grain that comes from intermediate wheatgrass. It was developed by The Land Institute and its partners through a long-term breeding program specifically designed to cultivate a perennial grain. Quality-controlled intermediate wheatgrass, such as the plants used to produce Kernza grain, may be seen as a "disruptive" technology, in that they introduce a continuous, living crop to farmers. Other grains must be planted annually, which requires substantial inputs and effort, adding costs for farmers, and leaving soils vulnerable to erosion and weeds. Conservationists have made it a priority to "perennialize" U.S. cropping systems, and intermediate wheatgrass is an especially good candidate for such a system because it is a "dual use" crop, offering grain for human consumption, while also feeding animals with forage and various byproducts

UM: How did intermediate wheatgrass enter U.S. agriculture, and what is the current state of adoption?

PK: Agricultural researchers have been working on intermediate wheatgrass breeding efforts since the 1980s. ARS played a key role, as our researchers collected the first specimens from the Black Sea region. In the early days, researchers at the Rodale Institute chose intermediate wheatgrass from among many other perennial crops as a target for perennial grain breeding. Then, The Land Institute brought it to the Institute's breeding program, where it became the crop we now know. While adoption of intermediate wheatgrass is expanding rapidly, it is still in its infancy.

UM: What questions is ARS pursuing in its research? How is the research program set up, and why?

PK: ARS's research program is designed to determine how best to grow intermediate wheatgrass in different settings throughout the United States, as well as how systems that include it may benefit farmers, consumers, and the environment. The research is also designed to provide important feedback to breeders, so that they can target desirable traits.

UM: What are the benefits of intermediate wheatgrass for sustainability? How do perennial crops like intermediate wheatgrass fare under conditions of climate change, like droughts and erratic weather?

PK: As a perennial crop, intermediate wheatgrass requires fewer resources to farm over time compared to annual crops. It maintains a living cover, providing consistent protection of the soil surface and offering habitat for grassland species. Its deep roots can efficiently recover nutrient and water resources from the soil, and may also lead to greater soil carbon storage over the long run. In Minnesota, intermediate wheatgrass has even been found to efficiently scavenge nitrate from groundwater, highlighting its potential to protect water quality, such as in the state's wellhead protection programs.

In addition, newly-planted crops are extremely vulnerable to climatic stresses, so the perennial nature of intermediate wheatgrass is a means of adding resilience to cropping systems. Researchers are testing a major hypothesis that intermediate wheatgrass may be able to better acquire water and nutrient resources from soils than annual cereal crops, helping it during periods of drought.

UM: What are the main uses for intermediate wheatgrass in the marketplace?

PK: Intermediate wheatgrass has diverse characteristics that make it desirable for food, beverages, animal forages and conservation. A variety of food and beverage companies have been using Kernza — you can find Kernza products online, on the shelves of some major retailers, and behind the bar. Among other uses, Kernza can be found in baking flours, breakfast cereals, beer and even whiskeys. For animals, intermediate wheatgrass is used as both a conserved forage, and a grazed grass. Conservation plantings also already regularly include intermediate wheatgrass.

UM: Could intermediate wheatgrass eventually be cultivated on the same scale as other staple grains like wheat?

PK: It is best to view intermediate wheatgrass as a complement to our current production systems, providing a perennial component to existing rotations that are dominated by annuals. Intermediate wheatgrass is unlikely to completely replace grain crops such as wheat or barley, but, with market development, it has real potential to expand.

UM: What do farmers who are considering intermediate wheatgrass need to know?

PK: These are early days for farming with intermediate wheatgrass, so a lot of the recommendations for its agronomic, harvest and post-harvest management are under development. Fortunately, there is a vibrant and supportive community of producers and researchers to tap into. Currently, grain yields are low and markets are limited; farmers need to be motivated by more than profit to adopt it. Often, perceived conservation benefits are a major motivation for growing intermediate wheatgrass. These include potential for water conservation in areas where water availability is declining.

UM: If this research program is successful, what else might follow?

PK: The pursuit of perennial grains doesn't end with intermediate wheatgrass. Groups like The Land Institute have been extremely important to expanding this work. There are perennial varieties of wheat, rice, legumes, and oil crops that are being tested. Like intermediate wheatgrass, many of these crops require continued breeding to truly be ready for prime time. Undoubtedly, some of them will find their way into America's production systems and markets. Like intermediate wheatgrass, they will require communities of innovators to reach their potential.

Grace Miner contributed to the answers above. She is a post-doctoral researcher with the ARS Soil Management and Sugarbeet Research unit in Ft. Collins, CO, and a member of the intermediate wheatgrass research team.