Domesticating Intermediate Wheatgrass for Sustainable Grain Production
Scientists and farmers working with pasture and agroforestry systems have long recognized the benefits of perennial crops that live for many years and do not require annual reseeding. Although some livestock production can be shifted to pasture-based perennial systems, humans depend upon grain. Decades of research have demonstrated that extensive planting of annual grain crops is inherently unsustainable. Although in the past plant breeders have had difficulty finding a role in sustainable agriculture, perennial grain breeding is a promising opportunity to transform agriculture. Intermediate wheatgrass (IWG) has potential to be the first widely grown perennial grain crop providing food for humans. More than 10 years of breeding IWG for grain production has already been completed, and methods for growing IWG are available. Long term outcomes of IWG grown in diverse cropping systems would include soil conservation, reduced nutrient leakage from fields, reduced pesticide application, reduced farmer input costs, and improved quality of life for society as a whole through improved natural resource conservation and wildlife protection.
The next critical step toward widespread use of IWG is the expansion of a breeding program functioning within a community of practice consisting of farmers, researchers, millers, and bakers. The community will learn about IWG through three on-farm trials, breeding efforts, milling and baking experiments, and grain chemistry analysis. Through these experiments, knowledge of the advantages and challenges of IWG production will grow, and the community will be able to more effectively inform the breeding work. Knowledge and attitudes of the community will be monitored through annual surveys, and broader interest will be tracked in a database of interested parties. Outreach will be achieved through publication in journals and the popular press, through academic presentations, and through plot tours.
- Increased optimism within the community of practice for potential of IWG to be a successful perennial grain crop. The community of practice is currently very interested in the potential of IWG to improve sustainability. Hands-on experience and documented progress in breeding will help us to move from interest to optimism.
Knowledge and experience gained by farmers and processors enables them to provide direction to continued efforts to develop IWG. Breeders are currently operating according their best guesses. Once farmers and processors have obtained hands-on experience, they will be equipped to provide valuable insight concerning agronomic and breeding objectives.
The number of farmers, processors and scientists interested in joining the IWG community of practice will have tripled in three years. Field days, publications, and tours will develop awareness of IWG, and a record of interested individuals will be maintained in preparation for expanded experimentation and planting.
Commercial plantings of IWG will be established and breeding programs will be initiated in other regions. This is an intermediate term outcome. Commercial plantings depend upon the development of improved varieties, agronomic practices, processing techniques, and marketable products. Although the current project is based in Kansas, the research conducted will provide a head start to programs in other states throughout the North Central Region.
This year a local micro-scale miller organic miller and baker began to experiment with IWG grain in milling and baking. This is a report she submitted:
I first worked with the milling qualities of Intermediate Wheat Grass (IWG) in comparison with Hard Red Winter Wheat (HRWW) for home use, using a small stone mill (Magic Mill) and a small steel mill (Whisper Mill).
I have found:
• Both mills worked equally well. The mills do heat up more with the IWG, so I was not able to mill large quantities without letting the mill cool down.
• The IWG flour is moister and more golden in color than the RWW.
• The bran or outer coating of HRWW mills finer and more uniform into flour. The bran or outer coating of IWG is more difficult to mill and is coarser.
One milling of IWG produced 65% flour with 35% bran sifted out using a 30 sieve. Milling it a second time produced 73% flour with 27% bran sifted out using again the 30 sieve.
One milling of HRWW produced 95% flour with 5% bran sifted out using a 30 sieve.
When milling just the IWG bran that had been sifted out, it produced only 24% flour and 76% bran.
I have since been working with the baking qualities of IWG in comparison with HRWW.
• I have substituted 100% IWG for many whole grain recipes that I normally use 100% of our HRWW flour with great success in appearance, texture and flavor. The results were basically darker in appearance, moister in texture, and sweeter in flavor. I have found IWG a great substitute for 100% whole wheat in brownies, banana breads, cranberry apple breads (pretty much all sweet or quick breads), muffins, cookies, and pancakes.
• Yeast breads are a different story. I have been experimenting with blending IWG in different percentages with our HRWW and other whole grain flours in yeast breads. The breads have a really nice taste (sweeter, maybe even a bit nuttier) and are darker in color than breads made with 100% whole wheat. They are heavier, do not rise as well and the texture is coarser. My last bread was about 15% IWG and 80% HRWW with about 5% vital wheat gluten which produced a pretty comparable loaf of bread.
• I have not tried the flat breads or tortillas yet, but plan to do that next year.
The first-year planting of one of the on-farm trials failed in the first year because the site received no rainfall for months after planting. The trial on this farm was replanted in the fall of 2007. The stand was good in 2008, but severe weed pressure resulted in the need to mow the plot to prevent large numbers of weeds going to seed in the first year. Because IWG grows slowly in the first year, it does not compete well with weeds initially. If the intent is to avoid herbicide usage, mowing (sacrificing the first year’s seed yield) may be necessary.
On the other two farms, weed pressure had been severe in the first year, but was reduced to nearly zero in the second year. One farm was planted in 30-inch rows and tilled with a row-crop cultivator. This site yielded 190 Kg/Ha of clean seed in the second year. The other site was solid seeded, and it yielded 175 Kg/Ha of clean seed in the second year.
We performed another cycle of bulked mass selection for seed weight and threshability. We used a seed size sorter to individually weigh and sort each seed harvested from each of 235 plants. Analysis of the data showed that the largest seeds predictably only appeared on plants with the highest mean seed yield. This result is an indication that bulked mass selection is an effective approach to increasing seed size. In other words, seeds can be harvested from many plants in bulk, and the largest seeds sorted out to effectively select only from the plants that have the largest seed on average. In the fall, 240 plants were established in the field from the largest seeds.
The main plant breeding activity was advancing the recurrent mass selection program. In 2007, a 4000-plant nursery was established. In 2008, we collected data on height, disease resistance, number of stems per plant, total yield per plant, yield per head, percent naked (free-threshing) seed, and 200-seed weight. In the previous round of selection we had evaluated only 1000 genotypes, and selected only for high yield per stem and large seed size. This time we had a population of 4000 plants, and were able to select simultaneously for short stature, high yield per plant, high yield per stem, a large fraction of naked seed, and a large 200-seed weight. Despite selecting based on more variables, we maintained selection differentials (selected mean-population mean) that exceeded those of the first round of selection for seed yield per stem and 200-seed weight. In fact, the mean yield per stem of the selected population exceeded that of the base population by 143%! This large differential indicates that seed yield may increase very quickly in IWG.
The 50 selected genotypes from the recurrent mass selection program were dug up and divided into three pots each. They were vernalized for seven weeks and placed in the greenhouse to intermate. Fans and weekly randomization of plant location were used to induce random intermating. By intermating in the greenhouse, we anticipate being able to complete a selection cycle in two years rather than three. Also, greenhouse intermating with fans and pot shuffling is likely to result in more random crossing than can be obtained in the field.
We evaluated selection methods based on seed yield per head in spaced plants by using row plots derived from separate mother plants (in other words, half-sibling progeny testing). The results indicate that selection for seed size and yield in spaced plants will successfully increase seed size in mature plants growing in rows.
We tested grain of two IWG samples (different field locations and genetics) to determine its nutritional profile as a whole grain.
Additionally, we tested for the presence of gluten that would produce a reaction in people with celiac disease (gluten intolerance). The test came back positive, which indicates that IWG, like wheat, rye, and barley, is not a suitable food for people with this condition. Had the test been negative, IWG might have quickly found a high-value niche market.
[To view the figures from this report, contact the NCR-SARE office at email@example.com.]
In the past year, we have given field tours or presentations involving IWG to more than 1000 individuals. Additionally, we have strengthened relationships with potential processors and retailers of IWG grain, with the intent to do a trial run when adequate grain can be grown. Furthermore, we have developed a Wikipedia entry about the crop at: http://en.wikipedia.org/wiki/Thinopyrum_intermedium.
Impacts and Contributions/Outcomes
Progress toward the broad outcome of increasing optimism and experience with IWG is well underway. One key area of progress was experience with establishing IWG on farms. Because the crop is perennial, it establishes a bit more slowly than wheat and doesn’t compete well with weeds in the first year. But also because it is a perennial, it effectively excludes nearly all weeds in the second and later years. In order for the crop to be viable, we will need to develop a method to achieve establishment, obtain a grain harvest, and prevent weeds from proliferating during the first year. Although optimism among farmers surged upon seeing the second-year establishment, that optimism will be curbed if we don’t develop first-year management strategies.
In the intermediate to long term, increasing IWG yield and seed size through plant breeding will be critical to achieving commercial success. Most plant breeding methodologies have been developed for domestic annual grain crops. We are continuing to develop and refine strategies for breeding perennial grain crops that are still rather wild. As we demonstrate the capacity to achieve rapid gains in yield and seed size, we expect support for intermediate wheatgrass to grow. Only when IWG is seen as an economically viable crop will it be widely planted and begin to provide sustainability benefits: reduced erosion, reduced nitrogen loss, reduced pesticide application, and increased net profit to farmers.
Bennington, KS 67422
Assaria, KS 67416
Bennington, KS 67422
Hearland Mill, Inc.
Route 1, Box 2
Marienthal, KS 67873
Heartland Mill, Inc.
Route 1, Box 2
Marienthal, KS 67873
Hillsboro, KS 67401