Final report for FNC22-1343
Project Information
The farm is owned by Kerri Meyer and Jen Blecha; two additional .75 FTE staff and several seasonal interns worked on the farm during this project. The farm is also home to a nonprofit religious organization served by 400 volunteers who engage in regenerative agricultural practices. We have 6 acres of perennial crops, mostly fruit. The prior farmers planted most of the orchards and fields between 2013-2018. We grow apples, pears, plums, raspberries, currants, gooseberries, seaberries, grapes, asparagus and rhubarb. At the beginning of this project, the operation was USDA-certified organic. We, the owners, elected to drop Dual-purpose ducks were intensively, rotationally grazed under an established vineyard for the purpose of pest, weed and grass management and for the added benefit of increased soil fertility. Portable housing, fencing and water permitted use of the ducks’ foraging behavior and controlled application of manure. Winterized housing made it possible to start each growing season with a sizeable flock that provides effective stocking density early in the year, preventing annual weeds from going to seed and disrupting insect pests' life cycles. Pathogen testing helped monitor for risks associated with livestock in perennial food crops. Eggs were sold, at first, which offset costs of feed and labor; later, eggs became part of the nonprofit’s food access programs. Drakes in excess of stocking density were slaughtered on farm; the original proposal planned for drakes to be sold for meat but circumstances made this impractical. Desired outcomes included reduced insect pressure and weed pressure, fewer paid labor hours and less fuel spent weeding and mowing in the vineyard, improved soil quality, and added income from duck eggs and meat. Findings are shared through an online presentation, written articles, field days, and a conference presentation.
our organic certification in 2023 in favor of using increasingly regenerative practices to improve soil health and ecological diversity and building direct relationships with the people fed by the farm’s produce. Our practices integrate chickens, ducks and goats into the management of cropland and woodlot.
Dual-purpose ducks were intensively, rotationally grazed under an established vineyard for the purpose of pest, weed and grass management and for the added benefit of increased soil fertility. Portable housing, fencing and water permitted use of the ducks’ foraging behavior and controlled application of manure. Winterized housing made it possible to start each growing season with a sizeable flock that provides effective stocking density early in the year, preventing annual weeds from going to seed and disrupting insect pests' life cycles. Pathogen testing helped monitor for risks associated with livestock in perennial food crops. Eggs were sold, at first, which offset costs of feed and labor; later, eggs became part of the nonprofit’s food access programs. Drakes in excess of stocking density were slaughtered on farm; the original proposal planned for drakes to be sold for meat but circumstances made this impractical. Positive outcomes included modest increases in soil organic matter, significant reductions in soil pH, and three years of clean food safety tests. Hoped for outcomes that were not demonstrated included a reduction in labor hours compared to weeding and mowing in the vineyard and added income from duck eggs and meat. Findings are shared through an online presentation, written articles, field days, and a conference presentation.
- Evaluate the usefulness of ducks in controlling grass, weeds and insects and improving soil fertility in a high-trellis midwestern vineyard.
- Identify the ideal equipment for vineyard use of ducks in this climate (particularly housing, fencing and water).
Determine whether egg and meat sales significantly offset the cost of feed and labor.- Quantify the ideal stocking density and rotational pacing for a small-scale vineyard.
- Ascertain whether food safety issues affect the viability of this practice.
- Share our learnings through field days, social media and a conference presentation.
Research
The materials and methods for this project remained largely consistent throughout its duration. Originally a two-year project, the research was extended for a third season, concluding in late 2024. Challenges and adjustments are discussed in the “Lessons Learned” section of this report.
2022 Setup and Practices:
- In 2022, we launched our duck integration experiment with an existing flock of 26 Ancona and Swedish Black Ducks. We planned to increase numbers and breeding stock by purchasing additional started ducks, but an HPAI outbreak lead us to incubate eggs from our own stock on the farm. Incubating and brooding added significant labor hours. Ducks moved onto the vineyard rows by late May.
- Our 1.5-acre vineyard has 26 rows of several varieties. We selected control and experiment rows that contained repeating varieties of grapes, including Trollhaugen and Somerset. The research rows comprised 20% of the entire vineyard.
- We used electric poultry netting to define mobile pens around the vines and set up hoop-style shelters that could be moved with a dolly.
- Our goal was to rotate ducks through designated vineyard rows every 5–6 weeks, giving rest periods between grazings and determining an ideal cadence. Incompatibility between the vineyard trellis system and the
- Water access was a challenge, with hoses stretched from a hydrant 500 feet away from the research rows. Pools and drinkers were moved and cleaned every other day.
- Feed was supplemented daily using an 18% protein ration. Ducks were also given access to grit and oyster shell.
- The prior owners of the farm used plasticulture. In 2022, we began the removal of plastic mulch from both the control and research rows.
- Control rows received only mowing and weed whipping for weed control, and no animal integration. We used our regular applications of composted pelleted chicken manure, sulfur, and wood chip mulch in the control rows.
2023–2024 Adjustments:
- In 2023, duck management was expanded and refined with improvements to shelter mobility (e.g., removing low trellis wires to facilitate fence set-up, adding ChickLifts to the hoop coops in 2024).
- In 2024, mowing and weed whipping were added to research rows in late July and August to manage aggressive native prairies forbs and grasses encroaching from adjacent wetlands.
- Ducks were also allowed into three new rows not part of the study baseline, to improve soil fertility (no data was collected from these rows). This let us alter our rotation cadence.
Data collection:
Labor - In terms of data, we tracked the hours of labor spent on duck management and compared them to the hours spent on our usual practices of mowing and weedwhacking. A serious design flaw in our project is not considering the labor that it takes to maintain a flock over the winter so that there will be a useful number of birds on the ground in the spring. The hours of winter management far exceed the summer hours when the ducks are in use. If a vineyard had access to pasture-ready mature ducks that were then slaughtered, this would make the labor numbers far more meaningful and encouraging.
Soil - Our soil tests look at percentage organic matter and pH, and quantify both phosphorus and potassium. We have baseline nitrogen from past years' soil sample and may test nitrogen as well as phosphorus and potassium in the future. Each year, we did a pre-season and post-season soil test. We used the University of Minnesota to test our soil, continuing to build on a relationship between the institution and our farm.
Food Safety: We submitted samples for pathogen testing from both the control and research rows of the same variety of grapes at the same time. The samples were about 100 grams of whole berries of each variety, taken randomly from grape clusters that were harvested using our usual good agricultural practices (GAPs). (Bird nets are lifted prior to harvest. Bins of fruit are never placed on the ground. We have handwashing stations in the vineyard.) Based on GAPs workshops we've attended in the past, we opted to test for listeria, salmonella and E. coli, as these are common animal-borne pathogens. We inquired about testing for camphylobacter, but no area food labs could test our samples in-house.
We did not certify or sell our organic grapes from our research rows in 2022. After our clean pathogen test results in 2023 and 2024, we used the research grapes for the nonprofit’s on-farm purposes, sanitizing the harvest with peracetic acid as an extra caution.
Labor and Management:
Our records for 2022 show the labor hours are vastly higher for the research rows, even though we ultimately had more row-feet in the control than we had planned. Duck management took 169.5 hours, while mowing and weedwhacking the control rows took 44 hours. Duck management required 180 hours in 2023 and 210 in 2024 due to shorter rotation periods (4 weeks instead of 6) and additional weed management (weed whipping along fences). Control rows required 38 hours of weed management in 2023 and 50 in 2024, due to wet conditions increasing weed pressure. We did not have any labor for insect pest management in any year.
In 2023, an additional 6 hours were spent removing low trellis wires that obstructed fence placement.
It’s important to keep in mind that these numbers do not include the labor (November - March) necessary to winter a flock over. I would conservatively estimate that I spent 30 minutes a day managing the flock over the winter, totalling around 80 hours to get them through to the growing season each year.
Egg management with ducks takes significantly more time than with chicken eggs. There are no “roll-away” nest boxes for ducks, so the 20 dozen duck eggs produced by the pastured flock were reliably dirty and required about 2 hours of labor every week to wash, candle, and pack.
Soil Testing:
The soil test results from May 2022 are our baseline. We sent them to Extension Educator Annie Klodd at the University of Minnesota for comment. She noted: "The only red flag on the soil test report is that the pH is really high. For grapes, we want to see the pH between 6-7.5. That would not cause vine death, especially if the vines were able to survive for multiple years prior, but it could be one of the contributing factors paired with the drought. What a high pH does is make certain nutrients less available to the vines, so they may be nutrient-deficient even if the soil contains adequate nutrients. In this case, nutrients with limited availability would be phosphorus, iron, manganese, boron, copper, and zinc."
The soil test results from 2023 and 2024 show continued modest increases in organic matter and an appreciable drop in pH. Our final soil reports show the research rows finishing at a pH of 7.1, down from the baseline of 7.8. This is a highly desirable outcome and compares favorably to our control row practices of applying CPM crumbles and pelletized sulfur. Potassium levels seem to have increased to levels higher than the desired range for vineyards.
Food Safety Results:
Across the three years of this project, all our food-borne pathogen tests came back "NOT PRESENT" on all samples, both control and research. We tested for E. coli, listeria and salmonella. This is particularly encouraging, as food safety was and is a primary concern in this project.
PATHOGEN TEST RESULT Soil Sample May 2022 Food Safety August 23Food Safety September 23Food Safety September 24Food Safety August 24Food Safety 2024Soil Test 5Soil Test 3Soil Test 4Soil Test 2
Educational & Outreach Activities
Participation Summary:
In 2023, we hosted a field day, which was scheduled too close to a holiday weekend. Two farmers attended that field day.
The nonprofit housed on the farm offers monthly educational opportunities for the public, which feature a visit to the project site in our vineyard. Approximately 210 people participated in these informal tours over the 3 seasons.
At the end of the first season, we shared a mid-project report in one newsletter article for the The Organic Fruit Growers Association 2023 edition of "Just Picked".
In Feburary 2024, the project was presented at the Marbleseed Conference in LaCrosse, Wisconsin, to an audience of about 40 people. The one-hour talk is available on SARE’s YouTube channel.
The final outreach product of this research is a narrated slide deck presentation sharing details about methods, outcomes and equipment reviews.
Learning Outcomes
As might be expected of applied, on-farm research, the most significant learnings from unexpected obstacles and less-than-ideal circumstances. Each season, we improved methods and adapted, applying what we learned through trial and error. Ultimately, we are pleased with the outcomes in soil fertility. We feel ready to have ducks deployed in case future years show increased pest pressure from Japanese beetles. Our most encouraging result is related to food safety, with three seasons of zero detected common pathogens.
The most important outcomes for us are the positive changes in soil fertility and pH and the reliable food safety results of this livestock integration (in combination with robust Good Agricultural Practices). The upshot of this research are that there seem to be no significant risks in having ducks in an integrated livestock vineyard management program, and there may be real benefits to soil health, as well. However, the labor required may not make this a cost-effective option for farms not committed to regenerative practices of poultry/fowl integration.
I'll frame the summary of our learning so far using the 5 goals of our inquiry.
- Evaluate the usefulness of ducks in controlling grass, weeds and insects and improving soil fertility in a high-trellis midwestern vineyard.
About the practice and labor, in general: We had fewer research rows than we intended because of the problems working with our trellis system (see below). That said, we only mowed the 18 rows that were planned as controls. In 2022, we spent 44 hours spent mowing and weedwhacking the control rows this past season. The cost of fuel was high this summer, but even the total costs for managing the vineyard with our usual equipment and practices were lower than the cost of 169 hours of duck care across the season. 2023 and 2024 required similar labor hours: Control rows required 38 hours of weed management in 2023 and 50 in 2024, due to wet conditions increasing weed pressure. Duck management required 180 hours in 2023 and 210 in 2024 due to shorter rotation periods (4 weeks instead of 6).
About weeds and grass: Our past success with ducks managing weeds and grass under our pear trees encouraged us to undertake this project. That success did not translate directly to our vineyard, in part because of the difference in the species of plants in our orchard floor versus our vineyard floor. The aisles and rows of our orchards are mostly clover and orchard grass and the main weeds are quackgrass and dandelions. Ducks do a fantastic job in those conditions. While the vineyard aisles were planted with fescue and clover by the prior farmers, they are dominated by weedy natives like sunflowers, sweet clover, bluestem, goldenrod that are encroaching from our CRP/WRP restored wetland, and by noxious weeds including reed canary grass and canadian thistle.
In order to be 'pure' about the research, we didn't mow or weedwhack in the research rows at all. By June, sturdy-stemmed weeds had taken over the aisles and rows of the vineyard. By August, the plants under our vines averaged 36" in height. If a vinegrower established a clean understory of low-growing grasses and clovers, the ducks would likely manage well. They did enjoy the cover and shade provided by the thick weed jungle.
In our conditions, this is not a cost-effective way to manage weeds or grass. If a practitioner were able to establish a vineyard floor of orchard grass and clover, ducks would do good work.
In 2024, for the long-term benefit of the vineyard and facilitation of netting, we weedwhipped and mowed all rows (control and research) in July and August. Our commitment to the science of weed management results was overcome by practical necessity. What this revealed, interestingly, is that while the ducks didn’t manage deep-rooted natives, they had effectively depleted the seed bank of dandelions in the vineyard. Ultimately, a mixed practice of conventional mechanical management of the vineyard floor with the use of ducks is a more realistic likelihood for future practitioners.
About soil fertility: Over the project, each year showed a modest improvement in organic matter and a much-desired decrease in soil pH. The baseline before the integration indicated OM at 3.3%. The experimental rows with ducks reached a high of 4.1% OM while the control rows (with our typical fertilization practices) finished the three-year period at 3.4%. With ducks and (I assume) the acidity of their droppings, the pH in the research rows dropped from 7.8 to 7.1, almost in the ideal range for viticulture.
Qualitatively, all our staff and volunteers agree that the research rows had more vegetative growth and the fruit set was better, which we attribute to the fact that the duck rows had daily fertigation from the pools and waterers, while some control rows languished with only drip irrigation under plastic mulch; the plastic mulch has been a barrier even to our typical fertilization practices.
Our commitment to this practice is now secured by demonstrated positive effects on our soil health. While grapes are tolerant of poor soil, the pH and organic matter of our vineyard were not ideal. The duck integration has moved the needle closer to our soil goals more effectively than our past practices of sulfur and pelleted manure application. If we can increase stocking density and do this for a decade, I think we’ll be pleased with the results.
About insects: Because of multi-year, low-level drought, and steady high winds, we didn't see much insect pressure in the vineyard during this project. 2023 did present us with our very first Japanese beetle, which I scouted on a grapeleaf in July. In complete failure as a citizen-scientist, I killed it a thousand times before I thought to see if the ducks would eat it.
- Identify the ideal equipment for vineyard use of ducks in this climate (particularly housing, fencing and water).
About fencing: In the success column, we feel that we've settled on the ideal fencing for our vineyard. The electric poultry netting was easy to install and effective at deterring land predators. The solar energizer with a 20-watt panel performed ideally under the conditions, including the thick weeds. That said, our trellis system (which we inherited from the prior owners) needed several hours of modification next season in order to make portable electric fencing practical. We train our vines to a 6’ high wire trellis, but in 2022 there were still 3’ wires where the prior farmers trained low cordons in years past. This low wire was removed in 2023 so that moving the fence as time-consuming and didn’t require so much mental geometry. (That’s 6 hours of labor we didn’t anticipate.) The difficulty in working with trellis meant that we did not rotate the ducks in the brisk cadence we had intended. Farmers planning to integrate poultry may want to plan their trellising system ahead of time, with electric fencing in mind.
About housing, etc.: We love the hoop coops that we designed and built. They're easy to drag by hand or with our compact tractor. They're tall enough for a person, but this made them vulnerable to wind. We’ve had consistently windy summers and experienced two 80-mph straight line wind events during the project. We ended up having to secure the hoop coops with earth anchors, which made rotating the birds to new ground onerous.
The hardest lesson we learned is that vines don’t provide cover against aerial predators like our orchard trees do. Because ducks don’t naturally put themselves to roost like chickens, we lost three nice hens to a nesting pair of great horned owls. Consequently, we added unplanned hours of labor (across the season) rounding them up and putting them to bed every night, in part because they don't use their housing in the same way a flock of chickens would.
Ducks need shade, which vines don’t afford in the same way as our standard apple and pear trees. We put up shade cloths between rows for the ducks’ well-being in hot weather.
Winter housing is very important, and we hoped that we'd have multiple portable winterized units. They're a challenge to design and build, and we only found the time and help to make one of the two that we'd planned on. Ducks require ample space and frequent mucking during the winter. Our portable wagon is still not ideal, though we're happy about the automatic poultry door's performance and the ducks' willingness to go inside the wagon on winter evenings. This saves time and worry during night-time chores. As mentioned in the methods section, we're pleased that the summer hoop coops become useful spaces for the ducks when converted to "solaria" using clear plastic cover.
In the future, we need to think seriously about over-wintering the duck flock as it takes infrastructure that we really don't have.
About water: As far as water goes, it's clear that one could never run ducks in a vineyard that didn't have a convenient water supply. In the dry, hot weather, we made 4 rounds of chores to ensure that the animals had plenty of fresh water. The tripod waterer is good in theory, but the ducks end up playing in the water, emptying the 8 gallons completely in a matter of hours. We ended up using a lot of homemade waterers made from 5-gallon buckets we got free from the bakery. Cutting holes in the sides of these buckets gives ducks access to the water for drinking and preening but prevents their bathing in it.
In 2024, a separate EQIP grant allowed us to install a hydrant in the vineyard, which was a game changer. Practitioners planning to integrate ducks into any perennial fruit crop should have water infrastructure in mind.
- Determine whether egg and meat sales significantly offset the cost of feed and labor.
Imagining that we could actually research this question was ridiculously ambitious of us. We did sell eggs, but in our research design didn't factor in the hours of time it takes to wash muddy, poopy duck eggs following food safety practices. With the rising cost of eggs, we may be able to help pay for feed, but the labor that it takes to find eggs in a weedy vineyard and to scrub them clean will never see a return profit. Also, plucking duck carcasses clean takes 5 times as long as a chicken. We will not be investing in egg-washing or duck-plucking equipment for this project and will likely set this matter of inquiry aside.
- Quantify the ideal stocking density and rotational pacing for a small-scale vineyard.
The outbreak of HPAI this past year disrupted our plans to purchase new breeding stock (happily, we had no incidence or losses). Instead, we raised a brood of cross-breed ducklings from our own hens and drakes. We also had a very hard time finding skilled labor to build out winterized moveable coops. In the end, we only had one winterized wagon. (One clever hack was that we converted the summer hoops to winter solaria by swapping out the canvas cover for clear plastic repurposed from our farm’s high tunnel after a storm.) We never managed to have as many webbed feet on the ground (40 birds rather than 60) as we wanted, which impacted our management plans.
Roughly, we found that our 40 ducks could manage weeds and enjoy good health on 1/10th of an acre for approximately 4 weeks. A shorter cadence would be beneficial if the housing is easy to move.
- Ascertain whether food safety issues affect the viability of this practice.
We are so pleased to report our findings on food safety. From our perspective, our only success is also our most important finding. We tested our fruit throughout the harvest, working with a Twin Cities laboratory that checked our grapes for E. coli, salmonella, and listeria. Over the three years of this project, every one of our pathogen tests came back at zero in both control and research rows. A next step would be to text fecal matter for pathogens to see if our clean tests are just because we have clean ducks.
Our farm uses Good Agricultural Practices in all our fields, but applying them assiduously was an imperative in this project. If this work can contribute to future conversations about National Organic Program (NOP) standards regarding manure withdrawal (a 90-day period, which pretty much precludes any significant use of poultry/fowl in perennial production here in Minnesota), we’ll be satisfied with our efforts. We’re small enough to be exempt from FSMA inspection; we’re USDA-certified organic, though, and our desire to integrate livestock was in conflict with our organic certification – so we dropped the certification. If we can demonstrate that it’s possible, from a safety standpoint, to have animals under vines through the season and with a shorter withdrawal period, perhaps in the future other growers can figure out their own cost-benefit threshold for experimenting with ducks in their northern vineyard.
- Share our learnings through field days, social media and a conference presentation.
Field days are hard to host, as farmers are busy and weekends are a hot commodity for members of the public. We’re hoping that our online slide presentation and the video of our Marbleseed talk will be of help to interested individuals.
That said, non-farmers who visited our vineyard during the nonprofit’s regularly scheduled events and volunteers days found the duck integration research compelling and inspiring.
Project Outcomes
From our perspective, the most important success was related to food safety. We tested our fruit throughout the harvest, working with a Twin Cities laboratory that checked our grapes for E. coli, salmonella, and listeria. It’s encouraging that every one of our pathogen tests came back at zero in both control and research rows. If this work can contribute to future conversations about NOP standards and FSMA requirements regarding manure withdrawal (a 90-day period, which pretty much precludes any significant use of poultry/fowl in perennial production here in Minnesota), we’ll be satisfied with our work on this project. If we can demonstrate that it’s possible, from a safety standpoint, to have animals under vines through the season and with a shorter withdrawal period, perhaps in the future other growers can figure out their own cost-benefit threshold for experimenting with ducks in their northern vineyard.
We are committed to this livestock integration for the long haul, as it fits our values and achieves desired outcomes, albeit in a way that’s not immediately cost-effective. There’s something particularly satisfying about discovering the ways in which animals and crops can synergistically contribute to the flourishing of a farm.