Final report for ONE22-408
Project Information
Bone Mountain Farm and researchers from the University of Vermont tested the winter survival and operational barriers to the adoption of winter vegetable peas, a dual-use crop that provides both the ecological value of nitrogen-fixing winter cover crop and a profitable early-season vegetable. We examined the intensity of deer herbivory, and tracked barriers such as labor and production costs. We found that although overwintering vegetable peas can survive a Vermont winter, expensive fencing is necessary to reduce deer herbivory, and the timing of harvest makes them impractical for many vegetable farmers. In much of Northern New England the timing of pea harvest will coincide with planting of higher value summer crops. Furthermore, the maturity of overwintering peas is only about two weeks earlier than spring-planted peas, reducing any market advantage for producers who might be able to market fresh peas early in the summer season. We performed outreach to growers and others in the food system to highlight the potential of overwintering peas through a recorded UVM Master Gardener podcast, an article for the Maine Organic Farming and Gardening Association, and conference presentations.
- Evaluate Austrian winter pea forage-type cultivars against new developed cultivars on a high elevation farm at the edge of zone four in the Champlain Valley.
- Identify any incidence other than cold stress that may significantly hinder the production of winter peas in the trial ecological region.
- Find ways to deal with barriers that limit winter pea uptake by integrating winter pea production with minimal interference on the existing production plan of our Collaborative Farmer.
Vegetable producers face significant challenges in maintaining soil fertility, reducing erosion, and nutrient loss. A sustainable strategy to combat these challenges is cover cropping, which is the method of planting a crop, not for its food production, but for its ability to manage soil erosion, soil quality, water, pathogens, and biodiversity (Reeve 2018; Kaye and Quemada 2017). Cover cropping accomplishes this by lowering the need for agricultural inputs (fertilizers, pesticides, herbicides, etc.) required by farmers, thus lowering their costs and limiting the amount of chemicals being released into the environment by agricultural runoff (e.g., SARE 2016, Reeve 2018). Before the following cash crop, a cover crop is terminated, either with pesticides or by turning it into the field (Keene et al., 2017). However, for many producers, the cost of seed and the interference with other farm operations (such as early season planting) make cover crop implementation extremely challenging (Roesch-McNally et al., 2018; Bergtold et al., 2019; Duke et al, 2022). Dual-use crops that provide the ecological function of a cover crop but are harvested as a food crop can provide multiple benefits to farms. If these dual-use crops can be grown in a fashion that allows for double cropping, farmers can harvest twice the output from the same land base, improving soil health and providing extra income from a second cash crop.
A popular overwintering legume cover crop used by vegetable producers in warmer parts of the United States is winter pea (e.g., NRCS 2011). Our recent research has shown that if planted sufficiently deep, new winter-tolerant pea cultivars can survive well when planted as late as the end of September in the Champlain Valley (Marques 2020, Brefo et al, in preparation). Yet most winter pea cultivars currently planted in our area are Austrian winter pea types that are primarily used for livestock forage due to their high starch content. However, efforts to cross traits of vegetable peas, such as sweet pods, into a cold tolerant background are beginning to yield dual-use peas.
Winter-hardy vegetable peas could be transformative if they allowed for double cropping. By planting them in the autumn and harvesting them before many spring or summer vegetables are even planted, they could provide the benefit of a cover crop by stabilizing soil and fixing nitrogen, but also provide income early in the growing season. With a harvest early in spring, before many soils have dried sufficiently to plant a summer crop, they should not impinge on production of summer vegetables. However, it will depend on the timing to actually work.
Vegetable pea cultivars come in several forms. Most have sweeter pods, with a lower starch content in seeds. Others have tendrils in place of leaves, and leaflets on tendrils, which improve their quality as greens. The USDA ARS breeding program under the direction of Dr. Rebecca McGee has crossed these traits, which are controlled by a small number of genes, into a cold tolerant Austrian winter pea background. Our first trial with these new cultivars, currently underway, shows that these dual-use peas have equivalent overwinter survival to Austrian winter peas.
Although dual-use peas that facilitate double cropping could be a boon for small, diversified vegetable farm that often struggle to use cover crops, barriers remain to their uptake (e.g., Roesch-McNally et al., 2018; Bergtold et al., 2019; Duke et al, 2022). Research is needed on operational barriers, such as lack of planters or cropping schedules for late season crops, which may hinder smaller or new farmers from adopting covering cropping practices. Furthermore, at the edges of zone four we are not certain that these peas can tolerate colder, longer winters.
Literature Cited:
Bergtold, J.S., Ramsey, S., Maddy, L. and Williams, J.R., 2019. A review of economic considerations for cover crops as a conservation practice. Renewable Agriculture and Food Systems, 34(1), pp.62-76.
Brennan, E.B., and Acosta-Martinez, V. (2017) Cover cropping frequency is the main driver of microbial changes during six years of organic vegetable production. Soil Biology and Biochemistry 109, 188–204.
Duke, J.M., Johnston, R.J., Shober, A.L. and Liu, Z., 2022. Barriers to cover crop adoption: Evidence from parallel surveys in Maryland and Ohio. Journal of Soil and Water Conservation, 77(2), pp.198-211.
Kaye, J.P. and Quemada, M., 2017. Using cover crops to mitigate and adapt to climate change. A review. Agronomy for sustainable development, 37(1), pp.1-17.
Keene, C.L., Curran, W.S., Wallace, J.M., Ryan, M.R., Mirsky, S.B., VanGessel, M.J. and Barbercheck, M.E., 2017. Cover crop termination timing is critical in organic rotational no‐till systems. Agronomy Journal, 109(1), pp.272-282.
Marques, E. (2020) Increasing the Agronomic and Economic Value of Chickpea and Pea. Graduate College Dissertations and Theses. 1232. https://scholarworks.uvm.edu/graddis/1232
Marques, E., Kur, A., Bueno, E., von Wettberg, E. J. B. (2020) Defining and improving the Rotational Value and Intercropping Value of a crop using a plant-soil feedbacks approach. Crop Science 60(5), 2195-2203. https://doi.org/10.1002/csc2.20200
Marques, E., Bueno E., Kerwein L, and von Wettberg E. (2024). Improving rotational partners: Intraspecies variation for pea cover cropping traits. Agrosystems, Geosciences, and Environment. 7. e20490. DOI: 10.1002/agg2.20490
NRCS 2017. A Comprehensive Guide to Cover Crop Species Used in the Northeast United States. Access April 4 2022, https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/nypmcpu10645.pdf
Reeves, D.W., 2018. Cover crops and rotations. Crops residue management, pp.125-172.
Roesch-McNally, G.E., Basche, A.D., Arbuckle, J.G., Tyndall, J.C., Miguez, F.E., Bowman, T. and Clay, R., 2018. The trouble with cover crops: Farmers’ experiences with overcoming barriers to adoption. Renewable Agriculture and Food Systems, 33(4), pp.322-333.
Sadeghpour, A., Adeyemi, O., Reed, B., Fry, J. and Keshavarz Afshar, R., 2022. Profitability of dual‐purpose rye cover crop as influenced by harvesting date. Agronomy Journal, 114(1), pp.627-640.
Sarrantonio, M. and Gallandt, E., 2003. The role of cover crops in North American cropping systems. Journal of Crop production, 8(1-2), pp.53-74.
SARE. (2016) Annual Report 2019-2020 National Cover Crop Survey, (August), 1–53.
Cooperators
- - Producer
- (Researcher)
- - Producer (Researcher)
- (Researcher)
- (Researcher)
Research
We performed a collaborative replicated field trial experiment to explore how vegetable-type winter pea cultivars perform at the cold fringe of zone four, on a higher elevation farm at the edge of the Champlain Valley. We performed this over two seasons, as annual variability in snow cover is growing, and can have a significant impact on overwinter survival.
Prior to planting, soil tests were performed. We performed a standard soil fertility test before and after planting. Bed preparation followed Bone Mountain’s current practices for preparing beds for summer cash crops. Planting was performed with the Jang TD-1 Precision Seeder, to get seeds planted deeply. Prior to planting, seeds were mixed with commercial inoculum to ensure the presence of suitable rhizobia for peas. We planted both years on September 15th.
In the first year the trial had four treatments, with three replicates of cultivars in each treatment combination. Peas were either planted alone or interplanted with rows of oats, a common cover crop cereal that may help insulate peas before it is freeze-killed. Furthermore, peas were either fenced to protect from herbivores (rabbits, deer), or left unfenced; this allowed us to measure herbivore pressure. Into these four treatments, we planted three cultivars of vegetable type winter hardy peas. In addition, we planted three Austrian winter peas (cultivars Windham, Blaze, and Coyote) as positive controls for overwinter survival, and two summer peas (Emerald and Amigo) as negative controls. We expected the second season to be a larger version of the first-year trial, but potentially integrating lessons learned in the first year. In the second year we reduced the planting to focus more on feasibility of larger scale production. We planted three cultivars. We removed the no fence treatment as it was clear that fencing is essential to effective production.
Following planting, we measured seedling emergence before the onset of snow, the density and diversity of weed species, and the presence of any diseases. In the spring we measured overwinter survival, days to flowering, days to maturity, yield, and quality measures. We used multivariate ANOVA to measure differences between the vegetable types and the Austrian winter peas, and the impact of the two treatments (oats/no oats and fence/no fence). Statistical comparisons were made in the R-statistical coding language.
In the first season, we had a partially successful trial. We had high deer pressure, and the fence we used was blown over by moving snow. Consequently, we did not observe significant differences based on fencing. However, based on observations at Bone Mountain Farm and on results in a parallel experiment at the University of Vermont horticulture research and education center (HREC) we determined that fencing is critical to larger scale production. Our cold-sensitive controls were successfully winter killed. Among the cold tolerant varieties, we had high survival (50-90%) among the winter tolerant varieties. There were varietal differences among 7 cultivars, but the overwintering vegetable types performed as well on average (no statistical difference) as the Austrian winter peas.
In our second year trial, we focused on a smaller number of cultivars and a larger planting to focus on feasibility of adaptation. We had reasonable overwinter survival, but high deer pressure. The larger fence we had surrounding the whole field was ineffective, and we had large losses of the peas. Overwintering peas in fields are a tasty green for deer in late autumn, and will require high levels of protection. We also observed that the field experiences winter heaving, which disrupted the peas. As the surviving peas were small, we decided to till in the trial to allow Tucker Andrews, the owner of Bone Mountain, to use the land more productively. Tucker has experienced major losses from flooding, and we did not want our research activities to interfere.
We have concluded that overwintering vegetable peas are not really viable as a crop in Northern New England at this time. We have observed that the winter hardy peas can survive the more challenge conditions at our high elevation partner farm. They can give a marketable crop early in the season. However, they need better fencing, and this is a major expense that will deter adoption. The winter of 2022-2023 had greater temperature variation, with warm spells, than other recent winters. This impacted the durability of our plastic fence. Fencing entire fields is likely not practical at scale.
We believe that overwintering peas are a viable option, but that the real challenge is spring harvest. Most farmers want to get on with summer, and are focused on planting high-value crops. They do not have the labor or interest in harvesting peas. In most settings they will just till them in, if they use them at all. It is home gardeners and specialty growers who we think are our best market. They may be better able to protect small plots. They may be better positioned to be patient with a few plots to take peas off of them. We have worked closed with Deb Heleba to get seeds out to master gardeners. New work from Ginny Moore at Cornell is offering seeds to a greater range of farmers.
We brought in Heron Breed to advise on reaching seed companies with this information, to explore possible seed company interest. Rebecca McGee, the USDA breeder who developed the overwintering vegetable peas, is in the process of registering these cultivars so that they can be released and licensed.
Education & Outreach Activities and Participation Summary
Participation Summary:
The project had several outreach components. For a field day, Bone Mountain participated in Vermont’s open farm week. However, devasting flood at Bone Mountain has led them to largely give up on farming. But before the flooding disaster, these field days will be critical in providing farmers with an in-person experience as well as an opportunity to interact with fellow farmers that are familiar with the varieties. We have a journal article in review which integrates data from this project and past trials. We have presented our novel approach to the farming community at Northeast conferences such as NOFA-VT and the UVM Extension small grains conference. We have done further outreach through social media and farming-oriented radio and TV programs, such as Vermont’s Across the Fence program and on the WDEV radio station. We strategically selected these methods to disseminate information because farmers listed extension websites, presentations at conferences, and extension agents in a 2020 survey we distributed, as the primary preferred method to acquire new farming information. We expect to also have the results on a forthcoming legume information hub on the UVM website, but its long-term home is not yet settled (https://uvmd10.drup2.uvm.edu/extension/sustainableagriculture/legumes). Collectively, our outreach methods have made knowledge gathered from this project easily accessible to the entire Northeast farming community.
The Green Peas of Spring: Overwintering Snap Peas as a Cover Crop and Early Season Vegetable,,Article in the Maine Organic Farmer and Gardening Association magazine, June 1, 2023.
https://www.mofga.org/resources/peas/overwintering-peas/
Learning Outcomes
Surveys performed by the UVM master gardener program, following our webinar, reported that participantswere interested in adding nitrogen to small plots and in having early season pea shoots.
Participants also expressed concern about spring harvest of peas. Consistently both diversified vegetable farmers and home gardeners expressed concern about labor and time for harvesting in the late spring and summer when overwintering peas would need to be harvested. This concern was expressed privately in many cases due to the aim of our project, but was also expressed after conferences. We performed several interviews to further document this concern from producers, which show that overwintering peas would need to be ready for harvest a month earlier, before the middle of May, to be available at a time when they would be more widely adopted.
Project Outcomes
We have not sought further funding for this work. We believe overwintering peas are viable. However, our results show that growers will not adopt overwintering peas because of labor shortages at harvest in June. The value of peas is not worth the the trouble. Most growers will turn in peas for the nitrogen, or at best harvest them as animal feed, rather than go to the effort of harvesting peas.
Because we do not see an avenue for wide adoption, we have decided to turn our attention to other crops. We do still have hope that gardeners or others will continue to grow these peas. For home gardeners, we do see an avenue for utilization, where they may be better able to protect peas from deer, and where the dynamics of labor allocation are different than on commercial farms.
The project supported the msc research of Emmanuel Brefo. He gained subtantially from working with our farmer partner. In addition, an undergraduate student, Eve Phillips, has benefitted from the experience. Visiting scholar Melike Bakir, an associate professor in Turkey, also assisted with the project.
The project allowed us to develop an effective working relationship with the UVM master gardener program which we hope will lead to future collaborations and outreach efforts.
We performed a set of key interviews to further understand the dynamics around harvesting peas in the late spring or summer. After three interviews we quickly realized that this was a major barrier to adoption. We still hope that home gardeners will have the interest to grow overwintering vegetable peas in Northern New England. But we are skeptical that under current weather conditions and market dynamics that this will be a profitable crop.