- Vegetables: beans
- Crop Production: cover crops
- Production Systems: organic agriculture
- Soil Management: general soil management
This project tests the nitrogen production and economics of three different fava bean varieties as a fall and spring cover crop, comparing seeding rates and planting dates to fit into existing agronomic or vegetable rotations.
This grant proposal is by Coveyou Scenic Farms which is a family farm run by David and Kathy Coveyou who are independent producers of agricultural products. The farm was originally homestead by our family in 1874 and is considered a Michigan Centennial Farm by the State of Michigan. The farm has historically been in dairy, potatoes and seed grains for decades. Since the 1970's our farm grew over 150 acres of cereal grains to provide high quality seed to other farms in northern Michigan. With the decline of family farms over the last 30 years this seed grain business model was not sustainable. Since 2000 we have been transitioning and building a diversified direct-marketed business model for our farm located in the heart of the tourist destinations of Walloon Lake and Petoskey. Our focus on pesticide free produce as well as superb quality flowers and seasonal trimmings has been well received by the community. We continue to expand our vegetable production and feel this project to explore fava bean soil building techniques is critical to our ability to improve our soil qualities after years of conventional tillage. Additionally, we feel that this project could help us explore once again growing a new fava bean cover crop seed on our land that would not only build our own soil nitrogen levels and organic matter but also provide an avenue for us to supply this seed to the larger organic and conventional grower community.
Improving soil structure and nutrient availability in the soil is of growing importance to many small organic produce farms as well as large commodity crop producers. Organic growers don’t have the option of adding chemical fertilizers to their crops and conventional farms struggle with the ever-increasing cost of those fertilizers. There is a true need in the agricultural community to improve soil structure and plant available nutrients and cover crops are a key method to accomplish this. The fava bean has some exciting potential to provide great benefits in this area.
The fava bean’s role as a food and feed crop in the United States is somewhat well-known, its potential as a cover crop appears promising, but is not fully understood. In addition, without widespread information about variety selection and potential benefits, current seed prices are often perceived as too high for an unusual and "unproven" cover crop. Available data on its nitrogen and biomass production potential is lacking, and where available, inconsistent. Preliminary investigations into its nitrogen and biomass potential are encouraging, especially as an early or late season fast-acting nutrient source. However, in the northern US, ideal variety selection, planting date, and seeding rate are important logistical questions that remain unanswered.
We plan to address these questions by implementing a spring- and fall-planted fava bean cover crop experiment across two seasons. Because fava beans can be sown at soil temperatures between 35 and 45 degrees Fahrenheit, early spring offers a promising window to establish a stand of fava beans before the first vegetable or corn planting (~May 15). Similarly, early fall offers a favorable period following a winter wheat or vegetable crop. Seeding between mid-July and mid/late August provides for good growth prior to winterkilling after several hard frosts. This research will investigate how much nitrogen the fava beans can produce before a summer cash crop in the spring and before the first killing frost in the fall. These short and often under-utilized periods of time on a variety of different farm types offer a unique opportunity for a fast-growing, nitrogen-fixing cover crop like fava bean.
Our spring-planted experiment will compare three different small-seeded fava bean varieties at three different seeding rates (drilled at 100 and 200lbs/acre and precision planted at ~150,000 seeds/a), all planted at the same time. The fall-planted experiment will compare the same three fava bean varieties on two different dates (mid-July and mid-August), with 200lb/a and ~150,000 seeds/a seeding rates for the mid-July planting, and 200lb/a for the mid-August planting. Our plots will be 10’ by 100’ with 3 replications arranged in a Randomized Complete Block design. This results in 27 fava bean treatment plots and 3 no cover crop controls each spring and fall.
Fava bean varieties used will be small-sized fava beans (~250-550 grams/1000 seeds), unlike the larger varieties grown for human consumption. When selecting the three varieties to research, we are looking for varieties with similar lengths to maturity, but different growth characteristics. We will compare one determinate variety, such as "Taboar", an indeterminate variety such as "Imposa", and a zero-tannin variety such as "Tabasco", also indeterminate. The different branching patterns will be compared through the different seeding rates, exploring whether fewer seeds can be used to produce an equivalent amount of biomass/N, thus reducing seed costs. The zero-tannin variety is significant because it can be used for livestock feed, offering growers an alternative market for harvested seed.
For biomass and nutrient analysis, aboveground plant tissue will be sampled and combined from three ¼ sq. m. quadrants per plot. This sample will be taken at the usual time of corn planting in the spring-planted experiment, and just before the first forecasted killing frost in the fall-planted experiment. A Pre-sidedress Nitrate Soil Test conducted in the summer after fava bean cover crops will be used to assess the relative potential of the cover crop to supply nitrogen to the next crop as compared to a no cover crop control.
After sampling the spring-seeded fava beans for lab analysis at the time corn or a similar crop would be planted, we plan to grow the fava bean crop to maturity to harvest the seed. There are two main economic reasons to explore this potential. First, is the opportunity to allow farmers to grow their own seed, reducing seed costs, and second, to explore the emerging market of soybean alternatives in the feed commodity market as consumers start seeking soy-free rations.
By investigating the performance of fava beans as cover crops in northern Michigan, we will be able to test farmer-friendly planting schedules, deliver regional production data, expand potential agricultural markets, and explore the potential to establish an alternative local feed/seed supply.
While some published research has been conducted on fava beans as cover crops, much of this research involved hard-to-find varieties or was carried out in different regions, such as California and Canada. Recent Penn State research experiments have demonstrated tremendous potential for biomass and nitrogen production – between 4,000-9,000+ lbs/acre, and 150–290+ lbs/acre, respectively. The wide range in values may be due to the central Pennsylvania location and varying planting dates of these early trials. This initial research is very promising but requires a separate study for the upper Midwest. Weather patterns that affect potential fava bean planting dates and frost-kill dates are highly variable in this region, and as such, conducting this experiment over two years would deliver the most regionally accurate information for prospective farmers looking to utilize this unique legume in the upper Midwest.
While cover cropping with legumes is not a new concept by any means, most readily available publications on the topic fail to include fava beans as an option, or only do so in passing. For example, a search of the SARE project database returns no projects utilizing them as cover crops, but a 2010 Northeast project report discusses that "the use of Fava beans as the legume instead of forage peas offers a superior nitrogen fixation if seeds were readily available" highlighting the interest in the issue but lack of seed as a constraint. This research, in addition to building on the aforementioned Penn State research, also investigates specific fava bean varieties and the potential for harvesting seed.
A related issue is the multiple names assigned to this species – horsebean, Chinese broadbean, tickbean, bell bean, Windsor bean, field bean, and faba bean – most of which reflect cultural or regional differences in nomenclature rather than varietal differences genetically.
Cover crops are often assessed by their ability to deliver much-needed nutrients, such as nitrogen, to the soil and quantitative assessments are critical for growers looking to adopt new cover crops into their rotations. Our measurements will provide nitrogen estimates, specific to the region and collected in multiple years, that can be used to compare nutrient sources and calculate one’s return on investment, something that has not been done before.
Our research will offer a unique factorial examination of some of the more regionally specific (i.e. planting date) and variable (i.e. variety and seeding rate) production considerations in a manner that works into existing crop rotations. This approach will build on various variety trials and minor investigations over the years with an eye specifically aimed at highlighting the potentially untapped opportunities this crop provides to farmers from both an environmental and economic standpoint.
Although regional data and knowledge on fava beans may be limited, this project affords us an opportunity to share the nutrient potential and emerging markets for this innovative cover cropping strategy with local and regional farmers alike.
We plan to work with Wendy Wieland of the Northern Lakes Economic Alliance who is on staff with Michigan State University Extension and a member of the Northern Michigan Small Farm Conference Planning committee to facilitate getting our findings published at the Michigan Small Farm Conference, which is attended by approximately 700 farmers in the state.
We also plan to produce a project fact sheet with relevant data, variety information, and overall performance/results that can be distributed at an on-farm field day and to groups like the Midwest Cover Crops Council.
Should the fava beans perform as an ideal cool-season cover crop alternative, we will share our results with regional seed suppliers to encourage the stocking and increase the availability of fava beans to growers throughout the state and upper Midwest. This is one of the most significant contributions this research could have because it would not only deliver the information to interested growers, but it will also help establish the capacity of the region to readily adopt this new cover crop.
It is our hope to involve associated MSU Extension personnel and sustainable agriculture staff through the course of this project to facilitate sharing of our lab results with associated researchers.
Evaluation of this research project will be approached in two main ways. The first is a statistical analysis of the data, looking at the results of the performance of the cover crops in the experiment. The second is evaluating what the broader impact of the project is on our farm and the broader farming community.
In our statistical analysis we will evaluate the performance of the fava bean cover crops at producing biomass and nitrogen and increasing soil nitrate levels. This will be done using appropriate statistical procedures such as Analysis of Variance and mean comparison tests. Our project consultant at Penn State will assist with this statistical analysis.
We also plan to assess the results of our project by evaluating the fava bean cover crop using an economic analysis. This information is important to farmers and can often be the determining factor in adopting cover crops. In order to evaluate the economic impact on the farm, we will analyze the nitrogen production to measure the value of nitrogen fertilizer that it would have replaced minus the seed and seeding costs. This would also tie into our plan to conduct an economic analysis of the seed harvest, looking to determine how much money one could get from selling the seed. In addition to measuring the nitrogen fertilizer replaced for an economic analysis, we plan to do an energy analysis comparing the cover crop energy inputs with the energy costs to produce nitrogen fertilizer.
And in order to evaluate the broader impact of the project in our region, we will conduct an end of project survey with farmers, seed industry representatives, and other attendees/readers of our outreach events and articles. This survey will help measure the adoption of fava beans for cover crop use, fava bean seed production, and seed sales. These are important indicators for the overall success of our grant project because they help evaluate meaningful changes brought about by this research. There are a variety of environmental and economic goods that can come from this project, and this survey of stakeholders will be critical to assessing the long-term value and contribution of this project to sustainable agriculture.