- Vegetables: beans
- Crop Production: cover crops
- Production Systems: organic agriculture
- Soil Management: general soil management
This project was run 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 homesteaded 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. Starting in 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 Boyne City and Petoskey. Our focus on pesticide free produce as well as superb quality flowers and seasonal trimmings has been well received by the community. Our vegetable production became USDA Certified Organic in 2014 with roughly 15 acres of production.
Before receiving this grant we carried out a number of sustainable practices. The main focus of the farm was a slow transition to organic certified systems from a conventional background. Our vegetable practice is now certified organic however the nutrient balancing of the soil along with removal of synthetic pesticide sprays has been in place for a number of years. The farm uses drip irrigation extensively, runs our walk in cooler using a geothermal system and produces all the electricity through a net metered solar PV array. Crop rotation has been used extensively; however, cover crops have not been fully utilized and are one of the motivations for exploring this project.
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 potential to provide 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. Our goal for this project was to explore the potential for fava beans as a cover crop for an early spring or late fall use in an organic vegetable production system.
Our process for exploring the potential use of fava beans as a cover crop involved 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 we believed offered a promising window to establish a stand of fava beans before the first vegetable or corn planting (~May 15). Similarly, early fall potentially offers a favorable period following a vegetable crop. Our desire was to 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.
Coveyou Scenic Farm was the principal investigator on this project. Brian Bates was our produce field supervisor and planned lead coordinator of this effort. Brian worked with fava bean trials during his undergraduate studies at Penn State and was a key motivator in trying to use fava beans in our northern climate. Brian played key roles in project planning, initial seed sourcing, seed preparation and inoculation and field mapping. Brian left the farm to pursue other ventures after our initial fall planting with the remaining study and evaluation left to David Coveyou who is the farm owner/manager.
David Coveyou worked to adjust the project after the initial fall planting results and carried on the project for the following year. David was responsible for all aspects of field prep, planting growth tracking, weed management, planting tool variations and soil testing and did much of the field work both years.
Field interns; Coveyou Scenic Farms hires agricultural field interns who assisted in various soil and seed preparation tasks. Some of the interns on the farm helped with various tasks over the years.
No outside organizations were involved in the actual implementation of the project.
Our Fava bean cover crop project was started in the fall of 2012 as planned. The cover crop was intended to go into fields that have just come out of vegetable production. In our case we choose to use two fields. One field had garlic in during 2012 while the other had onions. These fields were disked and chiseled plowed in preparation for the fava bean planting. A soil test was taken to document the baseline nitrogen as well as organic matter in the field.
We were able to locate and procure one variety of the small sized fava beans and used this variety in our initial fall plantings. How to seed this bean was originally a concern of ours with our existing grain drill being one option or the use of the local conservation district corn planter that could be rented as a second option. Review of the bean seed size focused our attention on the corn planter which we rented for use in our plantings.
The four row corn planter spacing was set to 5” in row spacing and the 36” row to row spacing was left unchanged. Changing row spacing is difficult on this corn planter. We instead seeded 300’ rows and ran the planter twice over the field just offsetting 18” to end up with an 18” final row width.
The Fava bean planting took place late September which is later than we preferred but likely representative when many produce fields could be cleared, prepared and seeded. This late seeding was worrisome but we were still able to obtain 6-9” of top growth with ¼” -3/8” diameter stems on very good field germination. The plants did not quickly winter kill even with frequent mild frosts. It took days into the 20’s to significantly retard growth. Even in early December we had living but frost damaged green foliage in place throughout the field. Interestingly it was the fava beans that attracted deer the most where they would dig through the snow to eat the top growth. It was encouraging to see a root system at least 6” long with a large number of single nitrogen nodules in place.
Soil tests taken the following spring did not reveal any significant increase in nitrogen levels in the field. Our conclusion is the there was not enough time to generate the growth needed to make a significant difference in nitrogen contribution with the density of the planting. Similarly the 6-9” of single stem growth provided minimal organic matter. The plan was to try again in the spring.
Our intentions for spring planting trials prior to vegetable seeding and transplanting was not successful in the springs of 2012, 2013 or 2014. Each of those years we received significant amounts of early spring rain or late winter thaws that prevented getting equipment into the field early enough to seed cover crops prior to vegetable planting. We believe this series of years were colder and wetter than most and were not dry enough to allow cover crop field prep and planting equipment to enter prior to when we wanted to be seeding or transplanting vegetable crops directly into those fields. Effectively, the spring is not allowing enough time for any cover crop seeding and growth prior to the regular planting season.
Our fall vegetable harvesting with the season extension efforts is pushing the dates when fields will be available for cover cropping later and later. Similar planting challenges existed in getting into the fields the following years along with similar results of poor crop growth. Our efforts continue even at the conclusion of this project to reduce plot sizes and expand our trial to compare the growth habits in the fall of a larger seed fava bean along with the smaller sized version. As we get results from these trials we plan to update this report with more hopefully positive conclusions on getting the growth and soil building capability we desire.
We believe fava beans may have great potential for building soil organic matter and providing a means of building soil nitrogen, but do not believe that at our northern latitude we can reliably use them as an early spring cover crop prior to planting our vegetable crops nor get enough growth from them with any croplands not planted prior to mid August. Using fava beans as a rotational cover crop on lands out of crop production for the year may be a better strategy. In that system one would need to explore if fava beans can outcompete the quick annual weed growth or if planting following an early incorporated rye crop could delay the weed pressure and allow for faster and better filling growth against weed pressure. Maximizing the nitrogen building benefits of the fava bean prior to weeds maturing to the point of producing seed is the challenge that would need to be explored. Fava beans mixed with other cover crops at the time of seeding may also provide a venue for growth while minimizing weed pressure during the establishment stage. In summary, we believe the documented results of fava bean contributions to soil building are worth continued exploration even if they may not be an early or late season cover crop in areas north of the 45th parallel.
The plan was to present our finding at the local small farms conference held yearly in our area if the results had promising significance to the larger farming community. Our inability to use fava beans successfully in the farm extremes of the shoulder season of our produce production was not viewed as being significant enough to warrant a conference presentation. We continue to share our knowledge and findings with our intern student base that frequent the farm and through USDA conservation tours that visit our farm frequently and through our local farmer to farmer twilight meeting schedule.