Domesticating Intermediate Wheatgrass for Sustainable Grain Production

Domesticating Intermediate Wheatgrass for Sustainable Grain Production

Summary

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.

Objectives/Performance Targets

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.

Accomplishments/Milestones

We continued three on-farm plantings. Two of these plantings are organically managed and were beginning suffer severe nitrogen limitation. These farms do not include livestock, and rely on legume rotations. Although one site did have sweetclover mixed with the grass, it did not provide sufficient nitrogen for the crop. Therefore, on one of the organic sites, there was zero harvestable yield, and on the other, the harvestable yield was only 50 lb of clean grain per acre. On the farm that was not managed organically, nitrogen was less limiting and yield was 250 lb of clean seed per acre.

A clear conclusion is that nitrogen management is an important area of research for this new crop.

This year we allowed the 4,800 plants placed in the field in the spring to establish. When working with a perennial grain, the plant must grow more than one year so that we can be sure that it is a strong perennial, so for the main breeding program 2009 was the establishment year. The seed will be harvested from each plant individually and selections made in 2010.

We continued to evaluate 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 also determined that yield was beginning to decline in these plots, and so have begun to explore the potential for breeding versus fertilization to reverse the yield-decline problem.

We also performed another cycle of bulked mass selection, where the largest seeds are selected removed from a large batch of seeds with a mechanical seed sorter. Again, this method has resulted in a substantial increase in the seed size of the population.

We have given tours and presentations to more than 1000 individuals in the past year. We have also published results of the research in a peer-reviewed journal. Several growers have expressed interest in producing intermediate wheatgrass on their farms once varieties are available. Intermediate wheatgrass has also been mentioned in the popular press, and retailers and bakers have begun to ask where they can obtain the flour.

This year a trial dehulling and stone-milling of the grain was performed on a commercial mill. Although we did not have funding for scientific baking experiments, we did successfully make an array of baked goods with the flour in our own kitchens. These goods have been well-received by the community.

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.

A second challenge to increasing optimism is sustaining yield and vigor. In this regard, we now see that soil fertility, particularly nitrogen, will be very important. On organic farms, this may be a challenge in the absence of readily available manure.

The best thing we did to enhance optimism was to establish a 27 acre field of intermediate wheatgrass (not funded by this grant). We found that farmers respond more readily to larger fields grown successfully than small patches. In the future, a better outreach strategy would probably be to have a singe 180 acre field than 10 collaborating farmers each producing 10 acres.

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.

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