Perennial Crops
What is an annual crop?
Almost all grains, dry legumes (pulses), and oilseed crops are annual crops, or “annuals”. Annuals are planted from seed, grow to maturity, produce seed or fruit, and then die, all in one year. Today, annual crops account for roughly 80% of the human population’s food calories and the vast majority of planted croplands worldwide. To successfully grow annuals, farmers have to suppress or kill the vegetation (weeds) that compete with crops for sunlight, nutrients, and water, especially when the crops are seedlings. Over millennia, farmers traditionally used implements such as hoes and plows to eliminate vegetation from the landscape before sowing annuals. This soil disturbance has caused significant amounts of soil carbon loss (which ends up in the atmosphere as CO2), soil erosion, nutrient leakage, and changes in soil organisms. Recently some farmers in the developed world have replaced reliance on tillage with chemical herbicides. This shift to “no till” cropping reduces erosion and tends to improve soil organic matter, but can still result in nutrient leakage, low soil organic carbon levels, and reliance on fossil fuel-based inputs that carry possible health risks.
What is a perennial crop?
Perennial plants do not have to be reseeded or replanted every year, so they do not require annual plowing or annual herbicide applications to establish. Perennial crops are beneficial to the environment; they protect soil from erosion and improve soil structure. They increase ecosystem nutrient retention, carbon sequestration, and water infiltration, and can contribute to climate change adaptation and mitigation. Overall, they help ensure food and water security over the long term.
Many fruit, forage, and some vegetable crops, including fruit trees, alfalfa, grapes, asparagus, and olive trees are perennials that have been grown for thousands of years. Scientists and our partners are working to add perennial grains, legumes, and oilseed crops to the list. Perennial grains, legumes, and oilseeds represent a paradigm shift in modern agriculture and hold great potential for truly sustainable production systems. In addition to identifying and developing perennial food crops, The Land Institute and our partners also conduct ecological intensification research in order to put those crop plants into diverse systems, striving to obtain sustainability features similar to those of native and natural ecosystems.
How do you create a perennial crop?
Scientists are using two approaches to breed perennial grain, pulse, and oilseed crops:
- Domestication of wild perennial plants
- Perennialization of existing annual crops
How do you domesticate a wild perennial?
Farmers have been domesticating wild perennial plants for the last 10,000 years. This is the approach that resulted in many of our current crops.Domestication starts with identification of perennial species that have one or more desirable attributes such as high and consistent seed yield, synchronous flowering and seed maturation, or seed retention, also called non-shattering (a feature of non-shattering plants that hold onto their seeds like an ear of corn rather than disperse them over the landscape like a dandelion). Large, diverse populations of the crop are grown in fields, and plant breeders select the best individuals for the traits of interest. These individual plants are then cross-pollinated, and the resulting seeds are planted to produce the next improved breeding population.
How do you perennialize an annual crop?
Many annual grain crops, such as wheat and rice, can be intermated with their wild perennial cousins. With persistence, plant breeders can obtain “wide hybrid crosses.” Although the first crosses are of little value, years of genetic studies and intermating can produce plants that maintain seed yield and quality similar to the annual parent while inheriting the perennial lifestyle from the other parent.
What perennial grain crops are currently in development?
Wild crop domestication is being used to develop intermediate wheatgrass marketed as Kernza®, perennial oilseeds, and perennial legumes. Wide hybridization with perennial relatives is being used to develop perennial wheat, perennial sorghum, and perennial rice.
Kernza® General Information
What is Kernza®?
A cousin of annual wheat and a long time forage grass, intermediate wheatgrass (Thinopyrum intermedium) produces Kernza® perennial grain. The name Kernza® is a registered trademark owned by The Land Institute.
Where does the name Kernza® come from?
The name Kernza® comes from the combination of two words. The first is the word “Konza”, in recognition of the Konza Prairie Biological Station, where Wes Jackson, co-founder of The Land Institute, saw an ecosystem that suffered little loss and required few inputs and dreamt of an agriculture that mimicked that natural system. It is important to acknowledge that Konza Prairie is itself named for the Kaw Nation people, whose homelands are the prairies. The second word, of course, is “kernel”, the part of the plant that humans rely on for sustenance.
Why is Kernza® trademarked?
Kernza® is trademarked by The Land Institute, a research-based nonprofit organization headquartered in Salina, Kansas in order to protect growers and consumers in the marketplace. Annual license agreements with The Land Institute allow growers to sell their grain with the trademarked Kernza® name. When grain sold under the Kernza® name is used in a product, the product manufacturer also has the right to use the Kernza® name to describe the product if they choose to enter into a licensing agreement. In order to insure the identity of Kernza® grain, acres that are intended for Kernza® production must be registered under an identity-preserved program. The Identity Preserve Program ensures that buyers are purchasing non-GMO, food-quality, 100% intermediate wheatgrass grain that was bred for grain production. If the name were not protected by a trademark, it could legally be used on products containing only annual grains like wheat, barley, or oats. A trademark helps to protect consumers, and ensures that growers are producing a grain that is truly perennial.
What are the benefits of growing Kernza® Perennial Grain?
Farmers produce Kernza® grain for a wide range of reasons, including environmental and soil health benefits. One farmer stated that his favorite reason for growing Kernza® was the habitat that it provided for bobwhite quail. Others are attracted to the ease of controlling weeds without herbicides or tillage (once the stand is established). Some farms with integrated livestock value the chance to obtain forage and a cash grain crop from the same field. For others, it’s the excitement of participating in something really new, and having the potential to reap economic benefits if they can be successful early adopters. Evidence is building that Kernza® grain can increase soil carbon, a key driver of soil health. Healthy soil benefits the farm in the long term, and in some regions there is the possibility of obtaining direct payments from carbon offsets to farmers that increase soil carbon.
Obtaining Seed
Can I sell my harvest as seed?
Not for use in planting certified Kernza® grain production fields without prior approval by The Land Institute. Seed needs to be handled differently than grain and will require different specifications and testing. Thus, seed producers and grain producers require different approval processes by The Land Institute. In order to be approved to sell your harvest as seed, you need written dispensation.
How do I communicate my interest in growing Kernza®?
All interested growers should fill out a Grower Application here. Having your information on file helps us determine your land’s suitability for the crop, set up a phone call, plan farm visits, and have easy access to your contact information for quarterly updates and questions and to explain the trademark licensing program. If you are approved, we will provide you with a trademark license to sign.
Can I plant Kernza® in my garden? I only want a very small amount.
Right now, we are prioritizing larger scale Kernza® plantings for seed and grain production in order to create a diversified farmer and market base for this new crop. This ensures the crop’s success for years to come. A minimum acreage of 20 acres is required to become a registered Kernza® grower.
I don’t live in the United States but I want to plant Kernza®. Where can I get seed? Who can I talk to about growing Kernza®?
Right now, seed for Kernza® grain outside the United States requires coordination with one of our research or market partners. Research is just now beginning in other parts of the world, so we hope that in five or ten years you will be able to plant Kernza® grain as an independent grower. Please note that it is a cool season grass, so it requires a period of at least 6 weeks with temperatures below 40 degrees Farenheit in order to produce grain.
I want to plant Kernza® grain for erosion control. Please advise.
Currently, seed supply is very limited, so it is allocated to plantings where the grain will be harvested and sold. There is a wide array of excellent perennial plants available to plant for erosion control. You might start by contacting your Extension Service or a local supplier of native perennial seeds to obtain recommendations.
I want to plant Kernza® between rows of my perennial fruit crop (i.e. trees, grapes, etc.) Please advise.
In our limited experience growing Kernza® near trees, we have found seed production was dramatically reduced. Your best plan will be to use species that are known to be well-adapted to this use.
Is Kernza® seed organic?
At this time there is no certified organic Kernza® seed for planting, but we expect organic sources to be made available soon. There is no transgenic (“GMO”) intermediate wheatgrass seed in existence.
How do I go about ordering Kernza® seed?
Right now seed is limited and only registered Kernza® Growers are provided with access to seed sources. All Kernza® seed sources require a signed license agreement prior to the sale of seed. You can apply to become a registered Kernza® grower here. If you are approved, we will provide you with a trademark license to sign.
Approval for becoming a Kernza® grower is based on your geographic location, experience with forage grass seed or small grains, and the resources available to you to manage Kernza®.
Kernza® Research
How do I become involved in Kernza® Grain research?
If you are a researcher, please submit an inquiry and provide details about your research here. If you are a grower and already have a relationship with a Kernza® grain researcher, please submit your application to become a registered Kernza® grower along with details about your research involvement here.
Where is Kernza® Grain research currently happening?
We have more than 35 collaborators in the United States and Europe. Research topics range from plant breeding and carbon sequestration to forage quality and grazing intensity. You can see more about our research network here.
Kernza® Qualities
Is Kernza® Grain gluten free?
No. Kernza® grain has gluten, but it is not as strong as the gluten in wheat flour.
What are the physical properties of Kernza® Grain?
Kernza® grain is not gluten-free. Protein content is high but variable. The gluten is weaker than the gluten in wheat flour. The baking quality is somewhere between that of soft white wheat and rye. Kernza® grain has been used in pancakes, pizza, bread, pastries, beer, and alcoholic spirits. Although the characteristics of the finished product vary based on the protein content, it can be used in the same culinary applications as other cereal grains (wheat, barley, rye). Makers find that the grain flavor properties vary from field to field depending on many factors that need to be studied.
Grading standards for Kernza® grain are still in development. In general, you can expect Kernza® grain to be about 20% of the size of wheat kernels, with a long and slender shape. Fiber content of whole grain Kernza® is much higher than wheat, but flour sifting can remove a substantial portion of the bran.
Where can I find a nutritional profile or analysis of Kernza® Grain?
Nutritional profiles have been done by private entities, University of Minnesota, and The Land Institute. This information has not been published in a journal, but we hope to have this type of data available to the general public in the coming years. In general, vitamin, mineral, and amino acid profiles are somewhat similar to wheat, with only a few striking differences.