What brought you here to The Land Institute (TLI)?
I’ve always been interested in agriculture, but I first thought about becoming a plant breeder early in my undergrad career when I realized that I had been “playing” plant breeding with my dad at home. We saved seed each year for the garden and had spent multiple summers trying to make “Husker” popcorn by replanting only the red kernels. Sometime later, probably around my sophomore year in undergrad, I read about The Land Institute (TLI) in Prairie Fire Newspaper, a periodical published in the Great Plains region that was always available at MoJava Cafe in Lincoln, NE. I was really excited that there was this unique research institute that had a novel idea to develop perennial grain crops. Not only that, but they were actually doing domestication, the breeding work necessary to make that idea a reality.
After finishing undergrad, I went on to graduate school in the Plant Breeding and Plant Genetics Program at the U of Wisconsin (I worked in cranberry, a woody perennial species), and there, I grew to love perennial crops and their unique breeding challenges. I continued reading about TLI’s work all the way through grad school, and I saw a legume breeding position pop up on the TLI website around Christmas in 2015. I was so excited that I applied before I had defended my thesis. So, for five more months after I was offered the position at TLI, I was still finishing up my graduate work, eager to get started exploring the possibility of developing new perennial legume crops.
The Land Institute’s research goals to develop perennial grains and perennial polycultures are founded in recognition that the world needs new crops and technologies to meet global nutritional demands while minimizing the ongoing degradation of soils and soil fertility. Each year, nitrogen fertilizer is applied on millions of acres across the globe to increase the productivity of annual crops. Unfortunately, less than 50% of applied nitrogen fertilizer is commonly taken up by crops. The rest is lost as N2O (nitrous oxide) and NO3 (nitrate), which causes negative environmental impacts elsewhere. Two innovations could reduce these and other impacts, including soil erosion: switching from annual to new perennial grain crops, and developing new nitrogen-fixing crops designed specifically to provide nitrogen to intercropped grains.
We initiated a new breeding program at The Land Institute when I was hired in the fall of 2016 to breed and/or domesticate new perennial legumes for two uncommon goals: 1) developing new high protein perennial pulses/grains that could substitute for lentils, peas, or beans in human cuisine and 2) developing legume crops that can be interseeded between rows of grains as nitrogen-fixing companion crops in diversified cropping systems. Both types of perennial legume crops could someday minimize our current dependence on synthetic nitrogen inputs in agriculture. Our program has been exploring and testing a variety of wild species and existing perennial forage legume crops we think might make good long-term domestication candidates.
In working with the Global Inventory Project, have you found many new species to evaluate and test?
There are too many new species! Through collaboration with Allison Miller and the Global Inventory Project, we’ve found out that there are more than 20,000 legume species in the world, and more than 30% of those are herbaceous perennial species. In agriculture right now, maybe 15 pulse crops or grain legumes are traded globally and there are maybe another 30 or 40 forage legumes. Obviously, there’s this great opportunity to find new perennial grain and companion legume species. We have identified a short list of candidates using ideas from the pipeline strategy for grain crop domestication and some of the legume specific criteria our program has developed.
Looking at familiar legumes, many are beans. Are beans considered grains?
We have this word “grain” that we could summarize quickly as a seed that can be easily harvested, dried, stored, and transported. Soybeans, beans, and peas are all common grain legumes. When I say, “a new perennial grain legume,” it would be something along those lines.
How many different species are you currently evaluating?
Currently, we’re trying to balance breeding maybe five or six species, which is a little bit hectic, with the goal of finding the most selectable or the most domesticable species. We plan to eventually choose one grain legume and one or two companion legume species. For potential grain legumes, we are focusing on sainfoin, alfalfa, and lupins… with a little bit of work exploring perennial chickpeas and licorices. We are exploring at a wider-variety of potential companion legume species, especially alfalfa and kura clover, but we also looking at other forage legumes like red and white clover, birdsfoot trefoil, Canada and cicer milkvetches. We are even beginning to look at some native species like goat’s rue, prairie turnip, tick-trefoil, and purple prairie clover.
Does using something like a clover instead of a bean leave more nitrogen in the soil?
Probably. Seeds contain large amounts of nitrogen that we remove from fields during harvest. Expecting a perennial legume to fix nitrogen for its own grain production, as well as for a companion, might be asking a little too much. For now, it’s much easier to envision a species like clover or alfalfa that’s an excellent nitrogen-fixer that is intercropped between rows of a grain, like intermediate wheatgrass (Kernza®). The companion legume, in addition to nitrogen-fixation and transfer, can still have additional roles like weed suppression or excellent forage value in dual-purpose cropping systems that produce grain for humans and forage for livestock.
Our program is very interested in developing companion legumes to be used in polycultures (or at least bicultures) with Kernza. We currently have a multi-state trial with locations in Kansas, Minnesota, and Wisconsin trying to understand which traits make alfalfa more or less compatible with Kernza in those unique environments. Ultimately, we hope to identify the most important traits so that we can use them as selection criteria.
You mentioned you are thinking about also harvesting alfalfa as a grain?
Yes. Alfalfa is one of the most valuable U.S. crops with millions of acres planted throughout the country. Farmers need access to alfalfa seed to plant those acres, and an industry exists which continues to generate valuable agronomic information about how to grow that seed. There has been some breeding done to improve alfalfa seed yields, but not much. In the U.S., alfalfa seed production fields are now commonly producing 600 to 1000 lbs. or more per acre. That’s equal to or even more than what we expect current Kernza yields to be, even after multiple cycles of selection, so it seems like a good candidate. However, alfalfa might have a more limited range of environments where it could be grown, and it requires quite a few synthetic inputs to attain the high yields I’ve mentioned.
We eat alfalfa sprouts – do we eat alfalfa that’s grown past the sprout stage?
A major plus for alfalfa is that it is generally regarded as safe (GRAS) ingredient in the U.S. In addition to sprouts, some people use alfalfa leaves for teas, and there has been research trying to extract protein from alfalfa leaves for human consumption. It hasn’t been something that we’ve thought about putting in a salad yet, because we are focused on perennial grain domestication at TLI – we want to develop storable crops that can meet the protein demands of this expanding world.
In addition to the Kernza+alfalfa trials going on across the U.S., do you have any significant collaborations that you see furthering the research?
It is essential that we continue to develop new collaborations in the U.S. and abroad, but to collaborate in perennial legume domestication research, we first need to produce seed to share with other researchers. We’ve only had two field seasons so far, which hasn’t been enough time to go through cycles of selection and seed bulking for any of our candidate species. Hopefully, we’ll continue to develop these collaborations as we begin generating new germplasm, but it’s a slow process. For example, the first year we evaluate a new species, we might select and then cross 50 plants. After harvesting seeds from that cross, maybe we can plant 1/20 of an acre, and after that, we can continue to expand and finally have seed to share.
We are starting to develop some international collaborations. I just returned from a trip to Palestine where a researcher is interested in breeding perennial companion legume species to grow under olives. I can imagine someday assisting people in other countries, like that researcher, to select candidate species and set up their own perennial legume domestication programs.
Overall, what are some of the biggest challenges to your work?
Because our goals are uncommon, we don’t really know what traits are necessary for stable, high-seed yields in perennial legumes or which traits are helpful for maximizing compatibility of legumes in crop mixtures. We are conducting preliminary research and pre-breeding that is necessary to learn what those desirable traits are through a combination of greenhouse and field experiments, so that the most important traits can become the focus of our breeding programs. At the same time, we are trying to design plant breeding populations with sufficient genetic and phenotypic diversity to allow us to make selections and future genetic gains towards attaining our breeding goals.
In addition to not knowing what traits to select for, we have been spending significant amounts of time learning how to grow the plants. We have been trialing various types of planting and harvesting equipment, greenhouse pots, temperatures, photoperiods and soil, etc. Meanwhile, we are trying to figure out how to successfully establish plots in the field; manage weed and other pest pressures in breeding nurseries; harvest, dry, and thresh small seeds from individual plants; and a myriad of other activities. Because we are working in nontraditional crops, protocols and machinery for these tasks are not readily available. In many major crops, these resources have been developed and refined in breeding programs over multiple decades. We are working hard to catch up.
Do you have any important recent discoveries that may help you narrow your species focus?
This new greenhouse is not necessarily a discovery, but it’s been an immensely important resource for our program this winter. The new greenhouse allows us to set the temperatures and the lights specifically for our crops and has done a better job keeping out greenhouse pests that were routinely damaging plants in our experiments. We were really struggling in the previous greenhouse space to grow plants, make controlled crosses, and perform the studies that we needed to be doing. I now have much more confidence going into 2019 and beyond that we will be able to generate the breeding populations we need to begin making selections and narrowing our species focus.
Do you do a lot of DNA work in the lab to determine what your most productive plants will be before evaluating them in the field?
Although we would love to use genomic selection to identify elite seedlings before field evaluations, we have not done any DNA lab work in our program. Before using genomic selection, we need to develop populations of plants, called training populations, and then collect DNA sequence data and trait data from those populations to build a genomic prediction model. Building a prediction model, especially in perennial crops, takes multiple years and we are only just beginning to consider starting that process. Furthermore, this type of genomic research is very expensive and not currently financially feasible for our program. We have been actively applying for federal and non-federal grants to expand the legume budget with the hope that we can implement this technology within the next few years.
What are some of your goals over the next 5-10 years?
I’m very excited about developing one or more companion legumes that can be intercropped with intermediate wheatgrass for dual purpose Kernza grain and forage production. I hope in five or six years that we have identified companion legume germplasm, made at least one cycle of selection, and conceivably have generated an experimental variety to be tested and compared to existing alfalfa and clover varieties. In addition, I’d like pick one or two species to focus on for grain legume domestication within the next three to five years. Finally, we would really like to continue to work towards implementing the genomic-assisted breeding strategies in our program, which we know will rapidly accelerate the rates of domestication and genetic progress we can achieve in our crop species.
I respect the patience of plant breeders – you must think about decades of work instead of next week.
This is very important to remember, especially in light of the 21st century challenge to simultaneously preserve soil fertility, increase crop productivity, and reduce our dependence on fossil fuels. When we think about domesticating perennial grains, what sort of timeline do we want to be on? Do we want perennial grains next week, or next year, or in the next decade… we’d prefer not to wait decades. To paraphrase something Lee DeHann said last year at Prairie Festival, “Ideally, we need impatient plant breeders. We want plant breeders that are trying innovate and adopt new technologies to reduce the length of their breeding cycles, to make more accurate selections, and ultimately, to increase their rates of genetic gain to reach breeding goals and release improved varieties within a realistic amount of time.”
As an example, let’s think about domesticating alfalfa as a new grain legume. Imagine we need to increase alfalfa seed yields by 200% to be competitive with other annual grain legumes. Because it is perennial, I can only perform one cycle of selection every three years, and I only increase seed yields by 10% per cycle. With a three-year breeding cycle, I won’t attain that breeding goal within my lifetime. But with a tool like genomic selection, we can make selections every year and attain that goal in potentially half the time. This is something that is an accomplishable goal in my lifetime as an early career plant scientist at The Land Institute.
As plant breeders and domesticators, we want to be patient and maintain the big vision of what we’re trying to accomplish here, but I think that we want to be impatient and leverage as many tools, resources, and modern technologies as we can to accomplish our goals. How much more soil erosion and soil degradation can we afford to happen on our crop lands? Can we wait 20 years? 50 years? 100 years?
Check out the other interviews in the series!
Interview with a Plant Scientist: Stan Cox, Perennial Sorghum
Interview with a Plant Scientist: David Van Tassel, Perennial Oilseeds
Interview with a Plant Scientist: Shuwen Wang, Perennial Wheat
Interview with a Plant Scientist: Lee De Haan, Kernza®
Support the work of Brandon and other plant breeders at The Land Institute.