Progress report for LNE19-382
Thirty participating small-scale vegetable farmers implement new tarp management plans to reduce their tillage intensity and report greater flexibility in bed management, 40 hours of labor savings, and an increase in net income by $1000 per tarped acre.
Small-scale vegetable farms (<15 acres) commonly depend on intensive, repeated tillage that is detrimental to soils and long-term productivity while continuing to struggle with weeds. For these farms, the consequences of heavy tillage are magnified by land constraints for sufficient cover crop windows and the high material and labor costs associated with organic mulches and amendments. These farmers represent an increasing majority of Northeast vegetable farms but there are few examples of successful reduced tillage (RT) and no-tillage (NT) management with scale-appropriate tools and equipment. These farmers have many concerns with reducing tillage, including weed and plant residue management, low soil temperatures and fertility, and poor crop establishment and/or lower yields. While RT strategies have been demonstrated to improve labor efficiencies and profitability on larger farms, benefits have been slow to accrue for smaller farms.
To advance adoption of RT on these small-scale vegetable farms, we will investigate opaque plastic tarps as a low-cost, labor-saving practice to reduce tillage intensity and add management flexibility. Despite farmer interest in tarping to address weed challenges, there has been little research that explores tarping as an RT strategy under a range of small-scale vegetable production systems. Our approach is designed to use tarps to overcome commonly cited concerns with RT. Our research and extension team, which includes our farmer advisors, will bring together expertise across the Northeast region (NY, ME, MA, PA) to take a whole-systems approach to advancing RT for these producers.
Our integrated research and education effort starts with farmer-centered workshops using Dialogue Education (DE) strategies that facilitate peer-peer learning. Together, farmers will identify opportunities for RT, evaluate tarp rotation strategies to reduce risks of RT, and design individualized on-farm RT transition plans specific to their own goals. Subsequent farmer-led on-farm experimentation will be supported over multiple years through direct consulting, virtual discussion groups, webinars, and field days that help farmers evaluate and share their results, participate in knowledge sharing networks, and learn research findings to foster continued innovation of these RT systems.
Using established permanent bed systems trials (NY, ME) with a history of different soil and crop management regimes, our research will explore how tarping, tillage and additional soil management practices change soil fertility, weed dynamics, and crop performance and the needed labor, equipment and other inputs required to improve success of RT and NT for small-scale vegetables.
1) Tarping will lower weed pressure and labor use and increase available soil nitrogen, crop productivity and profitability across tillage systems (Obj. 1)
2) Tarping effects will be greatest in no-till relative to conventional and shallow tillage systems (Obj. 1).
3) Tarping impacts on weeds, labor use, and profitability will be greatest within unmulched, bare soil systems (Obj. 2).
4) Tarping benefits will be optimized when combined with additional soil management practices (straw mulch, deep compost amended; Obj. 2).
We used a systems approach to investigate the effects of tarping, tillage, and soil management on soils, productivity, weeds, and labor to inform and guide farmers in RT and NT decision-making. Field experiments were conducted (Yrs 1 and 2) at two locations: Freeville, NY (Cornell University -Thompson Vegetable Research Farm, Howard gravelly loam) and Monmouth, ME (University of Maine - Highmoor Farm, Woodbridge loam). We leveraged the Long-Term Permanent Bed experiment (LTPB), established in 2014, that has compared six tillage intensities ranging from conventional tillage to no-till. Within tillage treatments, three subplot treatments were: 1) unmulched, bare soil 2) annual 5 ton per acre applications of oat straw (ME) or rye hay (NY); and 3) annual manure-based deep compost (locally sourced, 4cm depth). Our research inherited these valuable management legacies from past treatments to address our research objectives. We tested the effects of tarping, tillage, and additional soil management practices in a two year rotation that includes a direct seeded beet crop (Yr 1; 2020) and a double crop of lettuce and fall broccoli (Yr 2; 2021). The sequence of field management and data sampling follows similar timelines across both research farm locations with some variation based on field conditions and planting dates.
Objective 1: Evaluating tarping with deep, shallow, and no-tillage in a permanent bed system
While tarps have shown some potential to improve no-till systems, many farmers are still combining tarps with conventional tillage practices. Our goal is to understand how tarping changes soils, weed dynamics, crop performance, labor and equipment needs to improve success with RT and NT management.
Treatments: We tested three different levels of tillage (deep, shallow and no-till) with and without tarping in a two year rotation that included a direct seeded beet crop and oat-field pea cover crop in Yr 1 (2020) and a double crop of lettuce and broccoli in Yr 2 (2021). Tillage main plots consisted of three 4ft beds, 75ft long on 6ft centers that were split into three soil management subplots (25ft each), detailed in Obj. 2. Conventional, deep tilled beds were rototilled to 8in depth. Shallow tillage (<4in) was implemented using a rototiller adjusted to minimum depth. Untarped tilled beds were tilled 2+ times based on conditions to create a suitable planting bed. Tractor-based cultivation (overlapping beet knives) and hand tools (i.e. wheel hoe, flame weeder) was used in untarped no-till beds to undercut, kill, and remove weeds as necessary prior to planting. In ME, due to heavy weed pressure in untarped no-till beds, beets could not be planted and beds were tarped for the summer in an effort to maintain a no-till legacy and recover beds for future planting. For tilled and tarped treatments, tarps were applied following the first tillage event, left in place for at least 3 weeks, and removed at planting. In no-till tarped beds, tarps were applied for the same duration as tilled beds, directly over existing crop residue and any living weeds, removed and planted without any soil disturbance.
Field Management (to date): Tarps were applied in late fall 2019 after flail mowing a broccoli crop and left in place overwinter in preparation for planting beets in Yr 1 (Photo - Tarps applied). In spring, tarps were temporarily removed to implement tillage treatments (deep and shallow) and then reapplied for 3-4 weeks prior to planting beets. Beets (Boro) were planted by mid-June (3 rows per bed, 15in spacing) using a Jang seeder (Photo - Planting beets). In NY, overhead irrigation was applied after planting and as needed throughout the season. Irrigation was not possible in ME. Beets were weeded once using tractor based cultivation tools (between-row) and hand hoeing (in-row) at approximately 3 weeks after planting (Photo - Weeding beets). Beet stands were thinned 4-5 weeks after planting to not exceed 12 beets/ft. Beets were harvested by early August, 55-60 days after planting, based on crop maturity (Photo - Beets prior to harvest). After harvest, tillage treatments were applied, no till beds were hand weeded to remove mature weeds, and a cover crop of oats-field peas (100:50 lbs/ac) was drilled across the entire plot area in mid-August (Photo - Field in cover crop). In Year 2, tillage and tarp treatments were applied in April prior to planting lettuce (Tropicana) in mid-May to early June based on location (3 rows, 15in spacing; Photo - Field in lettuce). Lettuce was harvested in early July, and tillage and tarp treatments were applied over 3 weeks (Photo - Tarps between crops) prior to transplanting a broccoli crop (Emerald Crown) in early August (2 row, 24in spacing; Photo - Field in broccoli). The broccoli crop was harvested in early October and flail mowed. Both lettuce and broccoli were cultivated and hand weeded once between 3-4 weeks after planting (Photo - Weeding lettuce).
Data Collection and Analysis (to date): We used a comprehensive set of field measurements to evaluate tarp and tillage system effects on soils, weeds, labor, and crop yields over both years and for each crop in the rotation. Soil temperature was measured continuously at the soil surface (0-4in, Hobo Pendant) during tarp application and summarized to daily averages. Soil moisture (% soil water content; 0-8in) was measured using a portable TDR probe (Spectrum Technologies) before tarp application, at tarp removal, and every 7-10 days through the season until crop harvest (5-6 samplings). Soil inorganic nitrogen (NO3-N and NH4-N; 0-0-8in) was sampled at crop planting to assess tarp and tillage effects on early season, plant available soil N. Prior to cultivation and in-row hand weeding, weed counts were taken by species as a measure of treatment effects on weed emergence (Photo - Counting early weeds). Weed competition within the crop was measured at crop harvest by counting weeds above the crop canopy by species and by sampling total weed biomass (g/m2). For beets (Yr 1), beet populations were assessed at the time of thinning to measure treatment effects on beet stands (Photo - Counting and thinning beets). Total and marketable beet yields were determined by sampling roots and tops and sorting beets into size classes (Photo - Beet harvest). Cover crop biomass was sampled prior to winter kill (3 months after seeding) and sorted into oat, pea and weed biomass (Photo - Cover crop at sampling). For lettuce and broccoli (Yr 2), yields were collected on total and marketable heads and head counts were used to assess average marketable head size (Photo - Lettuce harvest). Soils were collected in fall (Yr 1 only) for bulk density to assess compaction (0-12in; 3 depth increments, Photo - Bulk density sampling). We documented changes in soil nutrients based on standard soil analyses (0-8in) in the fall of both years. All hand labor hours during the season were timed (e.g. applying fertility, bed preparation, handling tarps, hand weeding) and equipment operations recorded (e.g. tillage, planting, cultivations) to document total labor and equipment hours for use in crop budgets and to calculate net income per crop and over the rotation. All data is being analyzed for system effects (tillage and tarping) using R statistical software.
Objective 2. Integrating tarps, tillage and additional soil management practices to optimize RT systems
Organic mulches (e.g. straw, hay) and soil amendments (e.g. compost) used in combination with RT can provide soil cover and suppress weeds while building organic matter, soil tilth and good moisture retention but there are tradeoffs with each of these approaches. We tested how these additional soil management practices affect the functionality of tarps and success with RT and NT management.
Treatments: Within each of the tillage treatments described above we investigated three contrasting mulching soil management practices: 1) unmulched, bare soil 2) straw/rye hay mulch and 3) historic deep compost.
Field Management: A moderate compost rate (5-6 tons/ac) was applied to all 3 soil management treatments spring (Yr 1 and YR 2) with supplemental nitrogen added as pelletized composted chicken manure (Krehers, 8-2-2) based on nitrogen recommendations for each crop. Straw/rye hay mulch was applied the previous year (2019), left in place overwinter, and hand raked to between-bed pathways prior to tillage and planting beets in Yr 1 (Photo - Tarping over mulch). No mulch was applied to the beet or lettuce crop. Rye hay mulch (5-6 tons per acre) was applied to the broccoli crop after the first cultivation in New York (Photo - Applied mulch). No mulch was applied to broccoli Maine. Deep compost application in previous years resulted in over-accumulation of soil nutrients; the legacy of this practice is being examined in SMS 3.
Data Collection and Analysis: Sampling of soil temperature, soil moisture, soil nitrogen availability, weeds, crop stand, labor and yield were collected for subplots as described in Obj 1. We are analyzing data for mulch and system (tillage and tarping) by mulch interactions.
We are currently synthesizing our results across both locations and all crops in the two-year rotation: beets and oat-pea cover crop (Yr 1/2020) and lettuce and broccoli (Yr 2/2021). The current focus of this report is our results on weeds and crop yields. We assessed tillage, tarping, and mulching effects on weeds through a combination of measurements throughout the season, including hand labor for weeding and bed preparation prior to planting, early season weed emergence in the crop, and weed biomass and counts at crop harvest.
Effects on Weeds
Weeds at planting. Repeated tillage events (2-3x) were used to kill weeds and prepare the seedbed for planting in shallow and deep tillage treatments. We found that tarping helped kill these living weeds in tilled beds and effectively provided a weed free bed for planting in NT beds. Significant hand labor was invested in pulling and removing weeds prior to planting in NT without a tarp, which is likely to contribute to a significant portion of the total labor hours for the crop. Preliminary data on total labor hours suggest tarps could reduce total labor for NT by 20-30%, resulting in similar labor investments to conventional, deep tillage. We are working to summarize these labor results across crops and years, accounting for labor in bed preparation, hand weeding, as well as handling tarps. In ME (Yr 1), we found this weed pressure in NT without a tarp was too difficult to control and it was not justified to plant a beet crop. Instead, we decided to tarp this treatment to kill living weeds and prepare beds for planting the oat-pea cover crop in late summer.
Early season weeds in the crop. We found that tarping after tillage can lead to a dramatic reduction in weeds emerging in the following crop. This result is often described as stale seed bedding, where both tillage and tarping combine to induce weed seed germination and then tarping leads to seedling death by excluding light. When soils are not disturbed after tarp removal, this can leave fewer weed seeds to emerge and compete with the following crop. When planting beets in NY (Yr 1), tarping over bare ground after deep, conventional tillage reduced weeds by 73%. In ME, where weed pressure in beets was generally much greater relative to NY, tarping over tilled bare ground reduced weeds by 78% in deep tilled soils. We found similar results in Yr 2 of the rotation (Figure - Mid-Season Weeds in Lettuce and Broccoli by System). Tarping with deep tillage (averaged across mulches) reduced weeds in both lettuce and broccoli by over 75% in NY and 83% in ME (lettuce only). We generally found the same reductions in weeds when using tarping after shallow tillage, though this effect was less consistent across locations and crops. In ME, it was as high as 86% in beets and 76% in lettuce, and in NY it was only found for broccoli (73% lower). It was expected that tarps would drive changes in weeds that are dependent on the species. In NY, common chickweed was the dominant winter annual weed and hairy galinsoga was the dominant summer annual. Further analysis of these results by these dominant weed types will show if and how tarps are driving changes in the weed seedbank among summer and winter annual weed species.
We found weed counts in the crop were similar among NT and NT with a tarp and there were no differences in any crop or location (excluding beet crop in ME). Despite the presence of weeds in NT prior to planting, this suggests that through persistent hand weeding we still achieved similar early season weed control in the crop in NT without a tarp. This result shows that early season weed pressure did likely not contribute to any differences in crop growth among NT and NT tarp treatments.
When comparing NT with a tarp to conventional deep tillage, we found dramatic reductions in weed emergence (averaged across mulch), depending on the crop and location. For example, in ME, weeds in NT with a tarp were 84% lower in beets and 58% lower in lettuce (no difference in broccoli). In NY, weed counts in beets were similar but we found that NT with a tarp had 68% fewer weeds in lettuce and 92% fewer in broccoli. These differences in weed emergence between systems could be driven by a combination of factors, where tarps can affect the weed seed bank over time by; 1) promoting the fatal germination of weed seeds, 2) suppressing weeds between crops that would otherwise produce seed, and 3) in the case of NT, minimizing the introduction of new weed seeds from greater soil depths.
Weeds at crop harvest. We found that differences in weed emergence were generally consistent with an assessment of weeds at the time of harvest though high variability among treatments led to few measurable differences (Figure - Weeds at Harvest in Beets by System). In beets, we counted weeds above the crop canopy as an indicator of tall, crop competitive weeds and found that deep and shallow tillage without tarping led to the greatest number of weeds and tarping after tillage reduced weeds at both locations (average across mulches). In NY, tarping after deep tillage reduced weed counts at harvest by 65% and we found the same result in ME with shallow tillage. In NY, NT and NT with tarping had the fewest weeds above the crop canopy at harvest and counts were 84% lower than shallow and deep tillage. In lettuce, overall weed pressure was generally low in ME and very low in NY (Figure - Weeds at Harvest in Lettuce and Broccoli by System) This could be the result of our approach to weed management, where we used a combination of in-row hand weeding and between-row cultivation to control weeds across all treatments. Especially for a short-season crop like lettuce, these weeding operations likely kept weed pressure low regardless of treatment. In broccoli, we found that NT with tarping in NY had the lowest weed biomass among tillage systems (average across mulches) and weed biomass was 76% lower than conventional deep tillage.
Crop Stands and Yields
Beets (Yr 1). We expected that tarps could improve success with establishing direct seeded crops by creating a firm, moist and weed-free planting bed. We found that tarping can improve crop stands and establishment for beets though this result was not consistent at both locations. We did not find any differences among treatments in ME. In NY, tarping improved beet stand counts in shallow (all mulches) and deep tilled (bare and compost) beds. Shallow tillage with tarping had stands that were over two times greater than shallow tillage without tarping. We had heavy early spring weed cover, primarily common chickweed, in both shallow and tillage beds in NY prior to tillage, primarily common chickweed. Despite repeated tillage passes, it is possible that the presence of these weeds led to uneven seedbed conditions and/or beds were drier and lighter which contributed to poor seed to soil contact. We found that tarping prior to tillage effectively suppressed these early spring weeds and led to a clean and firmer seedbed that likely improved soil conditions for beet germination and establishment. This is consistent with our results in straw mulch. We also found that straw in shallow and deep tilled beds increased beet stands by 45-85% compared to bare ground. Straw that was left in place overwinter was raked into pathways and provided weed free conditions prior to tillage and planting. We found that beet stands were similar between NT and NT with tarping, regardless of soil management, which could be attributed to the labor we invested in hand weeding and removing weeds in the NT treatment. We also found beet stands were lower in NT compost mulch (both tarped and untarped) compared to bare ground and straw. Compost mulch beds have shown to be much lighter with lower bulk density, especially at the surface, and this may contributed to poor germination.
Despite these effects on beet stands, tarping after deep and shallow tillage did not lead to any measurable increases in beet yields (Figure - Total Yields in Beets by System). We did find that that NT with a tarp produced equal yields to conventional deep tillage at both locations and in ME, yields in NT with a tarp were more than double the yields in shallow tillage. Differences in beet yields were consistently driven by mulch, where we compared unmulched bare ground to the legacy of deep compost mulch and straw mulch. We found lower beet yields in bare ground relative to both straw mulch and deep compost at both locations (Figure - Total Yields in Beets by Mulch). Compost mulch yielded higher than straw in NY while these mulch treatments were similar in ME.
Lettuce and Broccoli (Yr 2). Similar to beets, mulch legacy had strong effect on crop yields. In NY, compost and straw mulch increased lettuce yields compared to bare ground (Figure - Lettuce and Broccoli Yield by Mulch) Compost increased yields by 20-34% and straw increased yields by 15-36% across all tillage and tarping systems. Tarping also increased yields in compost (16% increase on average) but had no effect within bare ground or compost. We found no differences in broccoli yields in NY, where marketable yields were relatively low (<2 tons per acre) due to a high incidence of Alternaria across the experiment (about 50% of plants produced marketable heads). In ME, we found tarping and tillage systems had no effect on crop yields for either crop. As we found in NY, yields were driven by mulching legacy and compost mulch yielded more than bare ground in both lettuce and broccoli. Yields in compost mulch were 67% greater in lettuce and 10% greater in broccoli. Yields in straw mulch were 19% greater than bare ground in lettuce and equivalent in broccoli.
Across all crops and both locations, we found that a NT system with tarps can provide equivalent yields to conventional deep tillage. Further analysis on tarping and weeding labor will show how tarping effects labor for NT and compares to tillage-based production systems. Compost mulch can have dramatic effects on native soils, leading to rapid accumulation of soil organic matter that can improve soil physical and biological processes, and we have documented how this practices can consistently lead to improved crop yields years after application. Further summary of our soils data, including effects on soil moisture during the growing season, soil nitrate, and soil nutrients will contribute to our interpretation of these yield results.
To begin, we shared our project objectives and desired outcomes with 1,000 vegetable farmers in Maine, New York and other NE states through email and online newsletters. Three hundred will respond to a survey about their current tillage, tarps, compost and soil management and inform Dialogue Education (DE) workshops.
We had 112 farmers considering or using tarps participate in DE workshops on “Tarping for small-scale vegetables”. Three full-day workshops took place (NY and ME, two per state) targeting 30-40 farmers each (Winter ‘19). Facilitator Stewart, a CCE vegetable production educator, is trained in dialogue-based education practices (Vella 2002; Global Learning Partners 2017). Dialogue Education format helps farmers overcome the hurdle between acquiring new information and changing practice. The strategy generates excitement among participants, supports their ability to integrate others’ experiences, and empowers them to adopt new strategies. Farmers left with a field plan to help them think through tarping practices suitable to their farm.
DE Workshops followed this basic format:
- Understand the perceived needs of participants related to tarping, gauge baseline knowledge of tarping, soil management practices, and RT and group participants by similar needs, scale, etc.
- Using dialogue approach, present new information (research and invited speaker experiences) and strategies, followed by discussion of concerns, additional information from farmers, etc.
- In small groups, farmers work together with facilitators to draft their own management plans.
- Small groups share insights with the larger group, ensuring that knowledge is available to everyone. Remaining questions are addressed by the larger group.
- Small groups reconvene and refine plans based on additional information.
- Whole group discussion on projected economic and soil health benefits that might be realized by the proposed changes, guided by existing research.
In spring 2020, we connected with DE farmers via phone and email surveys to follow-up on tarping plans for the coming growing season. Farmers were asked to share their goals and intended tarping applications. All participants were invited to join our RT network and receive in-season research updates on research trials and share observations through Cornell Small Farm Program social media (Facebook, Twitter, Instagram). In winter 2020, we again used email surveys to invite all DE farmers to share what tarping practices they implemented and the benefits and challenges that they experienced. We followed up individually via email with all those that responded (27) to learn more and dig into details. This survey was also used to collect ideas for our tarping webinars that offered in winter 2021. We hosted 3 farmer-to-farmer webinars, Tarp Talks, that re-engaged DE participants and other farmers across the Northeast (151 attendees) to share experiences among farms, address knowledge gaps and help refine practices for the following year. In the 2021 season, we continued to gather feedback from both DE farmers and webinar attendees through email and phone to understand how tarps were being trialed on farms and 23 farmers responded to our end-of-season survey, sharing details on specific practices and reflecting on the benefits and challenges. We worked directly with 3 farmers in on-farm demonstrations with side-by-side comparisons during the 2021 season to trial new tarping practices based on farm-specific tarping goals.
We will engage another 400 farmers in learning through winter meetings with farmer speakers who will describe their on-farm experiences (Winter ‘21-22). In summer 2022, we will host 2 on-station field days resulting in 100 additional farmers improving their understanding of tarping and RT practices based upon research results. We will synthesize on-farm results from 50 DE farmers and others engaged through webinars, field days, and on-farm demonstrations. Phone interviews will verify reported changes in practices and select farm stories will be shared widely through conference presentations, websites and popular articles (e.g. Small Farms Quarterly).
1. 300 small-scale vegetable farmers respond to a survey, sharing their current tillage, tarping, and soil management strategies and learning about our research goals (Oct ‘19).
In early October 2019, we developed and distributed an online survey (25 questions) to better understand how farmers across the region were using tarps, any challenges that they have experienced, and emerging questions that could be addressed through our research. The survey was shared through our established extension networks in NY and ME using electronic newsletters and grower lists, including our RT grower contact list in the Cornell Small Farms Program (400+). All registered workshop participants were also encouraged to complete the survey.
We had a total of 158 respondents to the survey with from 75% from NY and ME. Of these responses, 94 (60%) were already using tarps on their farm and 64 were not using them. Those farms using tarps were generally very small, 90% were farming less than 5 acres. Almost all (98%) were using organic practices on some part of their farm. About half (49%) had a gross revenue less than $10,000/yr, while others represented a wide range of annual revenue: 20% between $10,000 and $50,000, 16% between $50,000 and $10,0000, and 15% grossed over $100,000. Sixty one percent were beginning farmers (41% farming less than 5 years and 20% between 5 and 10 year) and 39% were farming for 10 or more years. We asked respondents that were not currently using tarps what reasons prevented them from using tarps. Of these, 52% were considering using them and they were mostly concerned with their costs and/or uncertain about how they could fit in their crop rotation.
This survey provides a better understanding the benefits, challenges, logistics, labor needs, tillage practices, weed issues, and compost management associated with tarping practices in the Northeast (Survey of Tarping Practices by Fresh Produce Growers). The survey captured a range of tarping experience, where 35% just started using tarps, 37% had found a couple uses, and 28% indicated tarps had become a big part of their farm management. Black plastic is the most common tarp material (83%) while some are using landscape fabric (13%) and clear plastic (3%).When asked where they were applying tarps, they were being used equally over permanent beds and shaped beds/open fields and were twice as likely to be placed over soil that was not cover cropped (48%) compared to cover cropped ground (20%). They were also commonly applied after harvest (over crop residue; 39%) and over sod (44%). Tarps were used across many different crop types, including direct seeded and transplanted vegetables, herbs/flower and small fruit. The most targeted crop was leafy vegetables (including lettuce, spinach, and mixed greens; 73%) followed by root vegetables (including carrots and beets; 60%) and vining crops were the least likely to be tarped (34%). Tarps were most commonly left in place for 4-6 weeks (38%) and for more than 10 weeks (30%). The use of this extended tarp duration was likely related to using tarps overwinter to hold beds/fields for the following year.
Based on the results of the survey, farmers are using tarps as a multifunctional tool to accomplish many different goals. A large majority of farmers used tarps to reduce tillage and improve soils (87%) and they are commonly used to increase early spring field access (84%). Eighty four percent of farmers indicated they were able to reduce their tillage with tarping. Farmers ware able to reduce tillage in several different ways, using less cultivation (66%), using less intense tillage (41%), and using fewer tillage passes before planting (40%). Sixty percent indicated they were able to tarp and plant with no tillage. Tarps were clearly an important weed management tool and used to manage weeds in several different ways, including to hold beds weed-free before planting (83%), to create a stale seed bed (76%), to kill emerged weeds prior to planting (66%), and to kill weeds after crop harvest (64%). A considerably smaller number of farmers were using tarps to kill cover crops (36%). The greatest challenges associated with tarping were logistical, including moving tarps among fields (50%, moderately or very challenging), applying and securing tarps (41%), and handling water ponding on tarps (38%). Some farmers were also finding it challenging to find time in the crop rotation (28%). Farmers also prioritized research questions to help inform our research directions. Three primary research areas emerged: 1) tarping to control weeds 2) tarping impacts on soil health and 3) tarping to advance reduced-till and no-till practices.
As members of the NE IPM Tarping and Solarization Working Group (2020-21), we shared these results with a group of researchers, extension educators, and farmers (virtual meeting summer 2020) and have worked to incorporate them into a practical online guide, "Tarping in the Northeast: A Guide for Small Farms", that will be released through University of Maine Extension in 2022. Survey results have also been shared with farmers and educators in conference workshops and trainings offered throughout this project.
2. 120 farmers participate in Dialogue Education (DE) workshops (60 in both NY and ME, 2 workshops in each state) that foster peer-to-peer learning, support evaluation of current tillage systems, and result in crop and rotation field plans to implement reduced tillage and tarping strategies (Feb ‘20). Participants, farmer advisors and workshop findings help refine research station treatments (NY, ME), which are implemented Spring ‘20.
In late September 2019, we announced our project and four full-day workshops, Tarping for Reduced Tillage in Small-Scale Vegetable Systems, targeting farmers interested in adopting or improving tarping practices on their farm. Workshops were advertised widely, using established extension networks in NY and ME, electronic newsletters and grower lists, social media (Instagram, Facebook), and our RT grower contacts within the Cornell Small Farms Program (400+). Workshop locations and venues were chosen to recruit farmers across the project region and in partnership with cooperative extension and non-profit partners based on location. We offered three of the four advertised workshops: 1) Northport, ME at the MOFGA Farmer to Farmer Pre-Conference on Nov. 2nd (45 participants) 3) Canandaigua, NY at Cornell Cooperative Extension-Ontario County (CNY; 39 participants) and 4) Voorheesville, NY at Cornell Cooperative Extension - Albany County (ENY; 28 participants). We cancelled a planned workshop in Springvale, ME to be held at the University of Maine Cooperative Extension of York County on Nov. 4th, based on low attendance and considering the state-wide appeal of the MOFGA Pre-Conference workshop. We registered a total of 133 participants and 112 attended across the three workshops offered. At registration, we collected information on tarping experience and asked for the most important topics/questions to inform workshop design.
Workshops were designed with two primary goals: 1) learn how we can use tarping to overcome barriers to reducing tillage in vegetables while managing weeds and improving soil health, and 2) identify specific changes we can make to farm management in the next year resulting in reduced tillage, better weed management, and greater profitability. Each workshop agenda followed a similar general format with presentations by a combination of researchers and invited farmer presentations (2 per workshop) followed small group breakouts/activities based on topic (Example Tarping Workshop Agenda). Content was structure into three general topical areas: 1) tarping as a RT and NT management tool 2) Weed management and tarp tactics and 3) Tarps and soil building. Workshops were designed and facilitated using a Dialogue Education (DE) approach (Example Facilitation Plan) to engage farmers in new information/ideas followed by facilitated small group discussion to integrate ideas, share concerns, and identify additional information needed. We began each workshop with an inventory of current tarping practices/goals and prioritizing issues to discuss through the day. The workshop ended with an individual exercise to give farmers the opportunity to outline changes to farm management using tarping (Farmer Field Plan). Overall, this workshop approach balanced new information with discussion to gives farmer time to think though and talk about new tarping strategies. One farmer shared "This was one of the BEST workshops that I have attended—ever. So much practical information. So many examples! Both farmer AND researcher info. Interactive, so well-organized with so little fluff or distraction. This workshop was exceptionally useful". Another said "Presenters kept us engaged, informed and enthusiasm made this an interesting and informative workshop!"
Evaluations from workshops gathered feedback on knowledge gained, specific new ideas learned, and tarping ideas for the coming year. A total of 78 evaluations were collected representing 70% of attendees, with a majority (65) representing farmers (Workshop Evaluation). Sixty five percent of responses rated the overall quality of the workshops as "Excellent" and another 30% rated it as "Good". Evaluations collected metrics on the amount of knowledge gained based on farmer knowledge before the workshop. For example, in ENY, before the workshop 14% had either a moderate amount or a lot of knowledge (4 or 5 rating) on the logistics of tarping and after the workshop this increased to 75%. This dramatic change in knowledge gain was similar with other topics: reduced tillage (from 7% to 64%), weed management (7% to 80%), cover crops (11% to 72%) and crop rotation planning (4% to 62%). We had a similar impact at other workshops. On the topic of reducing tillage, farmer knowledge levels (4 or 5 rating) went from 16% to 83% (WNY) and from 24 to 88% (ME). Attendees shared the most interesting lessons learned and 1 to 2 examples of how they will use the information on their farm in the coming year, including: how they can address tarping logistics (storing, securing, moving tarps), combine tarping with winter hardy cover crops for effective termination, using tarping for perennial weed control, and tarp timing and duration for different crops and in a rotation (New Tarping Ideas and actions).
3. 90 DE farmers and others participate in follow-up discussions via webinars, online surveys, email and phone to discuss and refine RT and tarping field plans for the coming year (Mar ‘20). Additional in-person winter training opportunities provide further support to farmers in on-farm planning and decision-making.
In late winter and early spring, we followed up with DE attendees via email and phone to learn about their tarping plans and ideas that had emerged since the fall workshops. All 112 DE participants were contacted in via email and about 10% (12 farmers) responded to a quick online survey sharing how they were planning to use tarps, their specific goals for tarping, and any issues or concerns (Spring 2020 planning). These responses gave us intentions for the coming year and led to follow up communications to help think though ideas and address concerns. We reached an additional 18 farmers through a combination of email, one-on-one phone consultations and online meetings to gather more detailed plans that helped us get into specific tarping applications in the season based on developing crop plans. We reached fewer DE farmers than expected in early spring, which in part could be attributed to the unprecedented challenges and uncertainties that emerged for farmers with the outbreak of COVID-19. We also recognized that our DE workshops reached some aspiring and beginning farms, many that had not yet acquired or used tarps, so they may have had less capacity to implement or trial the practice in the first year.
We followed up on interest generated by DE workshops and engaged a wider audience with 6 additional presentations and facilitated discussions for farmers interested in learning about tarping and RT practices on their farm. Our team reached an additional 225 farmers and educators through these workshops:
- Maher, R. Tarping for weed control. 12/11/19. New England Vegetable and Fruit Conference. Manchester, NH. 50 farmers, 0.5 hr.
- Stewart-Courtens, C. Tarping for weed control. Catskill Regional Agriculture Conference. 01/09/20. Delhi, NY. 28 farmers, 1 hr.
- Maher, R., Rylander, H, and Bonhotal, J. Digging deep into compost: Using compost in NT production. 01/17/20. NOFA-NY Winter Conference. Syracuse, NY. 75 farmers. 2.5 hrs.
- Maher, R. Reduced tillage systems for small scale organic vegetables. 02/05/20. In partnership with Kootenay and Boundary Farm Advisors (BC, Canada). Webinar. 20 farmers. 1.5 hrs.
- Maher, R. Survey of tarping practices by fresh produce growers. 07/13/20. NE IPM Tarping Working Group. Webinar. 15 educators. 15 min.
- Maher, R. Tarping weeds in reduced tillage organic vegetables. 11/04/20. CCE Ag-Inservice: Rapid research talks. Webinar. 40 educators. 10 min.
4. Of the 120 farmers who participated in DE workshops, 60 test field plans with alternative management of tarping to reduce tillage (Oct ‘20).
We gathered farmer intentions for on-farm tarp applications in spring through phone, email, and a short survey (30) and then collected feedback from farmers on how they implemented tarps at the end of the season (26). We exchanged emails/texts with farmers over the course of the season and had intended to do several visits but did not travel given COVID 19 concerns and restrictions.
5. 50 DE farmers report findings via year-end surveys and phone interviews, highlighting field observations, crop and labor impacts, and knowledge gaps and suggest refinements to improve results (Dec ‘20). General summaries of on-farm and on-station research are shared through local farmer meetings and electronic media.
In early December, we followed up with all 112 DE attendees via email and asked for farmers to share and reflect on their tarping trials this year via a short, online survey. About 25% of DE attendees (26 farmers) responded to our survey and shared how they used tarps (Year 1 Applications), what benefits they found, any issues or concerns that they had (Year 1 Problems), and if they are planning to try it again next year. Tarps provided a number of benefits based upon these on-farm applications, including:
- Less tillage. 53% used less intense tillage (e.g. shallower or gentler tools) and 31% made fewer tillage passes.
- Greater flexibility in field management. 65% found tarps helped hold beds weed-free until needed and 46% found tarps helped with spring field access.
- Better weed management. 62% found fewer weeds and 58% spent less time hand weeding.
- Improvements in crop establishment and yields. 53% found better soil conditions for planting (e.g. moisture, tilth) and 23% found better crop yields.
The challenges shared emphasized the logistical problems with tarps, holding and securing, hauling sandbags, and moving across the field. Based on these reflections, 39% of farmers will definitely implement the same practice in the next year and another 58% will implement the practice again with some changes to improve on it.
Through our survey, we also collected ideas on what more they want to learn to help us plan a series of webinars, TarpTalks, in 2021. Many farmers (11) expressed a strong interest in sharing what they have tried and learned with others. Based on this feedback, we planned a workshop series that addressed a broad range of targeted applications that enhance weed control with less tillage, including tarping in succession plantings, tarping with landscape fabric, and applications of tarps with cover crops.
Given their feedback on their experiences and interests in the coming year, we have completed individual email follow-ups to learn more details, gather pictures, discuss ideas, and maintain connected in the coming year.
6. 90 DE farmers and others are re-engaged via 2-3 webinars to learn results of on-farm experiments, share findings, and refine on tarping and RT practices. Webinar topics address farmer interest and knowledge gaps identified in follow-up surveys (Feb ‘21).
In March 2021, we hosted a series of lunchtime webinars, Tarp Talks, for farmers to share and learn about tarping practices with session topics and speakers guided by emerging farmer questions. This 3-week series had a total of 151 attendees and featured farmers from across the NE region and beyond sharing how tarping is being used on their farm. Topics included using tarps for holding beds, succession plantings, cover crop termination, enabling spring field entry, and handling problem soils and weeds. Farmer presenters were identified through direct outreach to those in attendance at previous in-person intensive workshops held in fall 2019 that expressed interest in sharing about their farm. Webinar registration responses (167 individuals registered; some registered for multiple webinars, 318 total registrations) provided us with information on our project reach and audience. Based on registration, 89% were from the Northeast region (10 different states) and 11% from across the US and Canada. Most registered participants were women (65%) and farming for commercial sale (64%). Twenty two percent were gardeners, homesteaders, and/or aspiring farmers and 11% served farmers. Participants represented a broad range of tarping experiences, with most identifying as exploring or just starting (32% not using tarps but considering and 31% just started tarping and experimenting), 22% having found several uses, and 16% with lots of experience where tarps have become a big part of their management. Webinars were recorded and posted on the Cornell Small Farms Youtube channel for viewing by a wider audience (total views 1,292; accessed Jan 20, 2022).
Details on webinar topics, speakers, and recording links are included below:
- Reserving Beds With Tarps: Setting The Table For When It’s Time To Plant. Offered March 16, 2021. Presenters: Rachel Cross, Spirit of Walloon Market Garden (Boyne City, MI) and Molly Comstock, Colfax Farm (Alford, MA). 1 hr. 478 views, accessed Jan 20, 2022. https://www.youtube.com/watch?v=1aGwjtGCUpo
- Pairing Tarping With Cover Crops: Getting Both On The Menu. Offered March 23, 2021. Presenters: Ben Stein, Edible Uprising Farm (Troy, NY) and Janna Siller, Adamah (Falls Village, CT). 1 hr. 499 views, accessed Jan 20, 2022. https://www.youtube.com/watch?v=KVvtLKa-vVk
- You Can’t Send Back Your Soils And Weeds: Tarping The Problems You’re Served. Offered March 30, 2021. Presenters: Maryellen Sheehan, Hartwood Farm (Chittenango, NY) and David McDaniel, Earth Dharma Farm (Jackson, ME). 1 hr. 315 views, accessed Jan 20, 2022. https://www.youtube.com/watch?v=e31ClYQxS3U&t=5s
Webinar evaluations gathered feedback on content, knowledge gained, and specific new ideas learned. A total of 34 evaluations were collected across all 3 webinars, representing 23% of attendees. Sixty three percent rated the overall quality of the webinars as "Excellent" and the remainder, 38%, rated them as "Good". Evaluations collected metrics on tarping knowledge before the webinars and amount of new information they learned. While most had considerable knowledge (responded “A Lot” or “Some”) of how tarping can be used for improving weed management (73%) and to reduce tillage (64%), fewer (48%) had knowledge of how to plan for tarping in their crop rotation, with just over half (52%) having “Little” to “None at all”. Despite the broad range of tarping experiences and knowledge among attendees, evaluations showed that webinars provided most with valuable new information (based on those responding “A lot” or “Some”) where 64% learned how to source tarps to fit the application, 91% learned how to handle the logistics of tarping, 82% learned how to plan for tarping in the crop rotation, 91% learned how to use tarps as a weed management tool, and 85% learned how they could reduce tillage. Attendees shared that they learned how to use different size tarps and tarp materials for different uses in crop rotation and/or bed prep, how landscape fabric can be used as a tarp, and helpful tips for folding up, storing, and labeling tarps. On the topic of managing tarp logistics and using in a crop rotation, attendees shared that they valued learning how to use tarps to hold beds until they are ready to plant, fold tarps back to open new beds and hold the next, and the importance of prepping the bed (including amendments) in the fall for getting onto beds early the following spring. Farmer presenters shared how tarps can be used in many different applications and planting windows. As one attendee shared, I learned to “make your tarps work all the time”. One webinar focused on integrating tarps with cover cropping practices, where we learned that 57% of attendees had little to no previous knowledge of how to use tarps with cover crops. After the webinar, all of them (100%) indicated they learned new information. One attendee shared, “I never thought to kill winter rye with tarps”. The farmer-to-farmer webinar format also provided opportunities to talk about the missteps and challenges. One attendee shared, “I really appreciated all of the images of the struggles -- the things that didn't go exactly according to the plan. When we struggle we can feel alone. Nice to be supported and learn from other people.” Overall, evaluations showed that 88% of attendees intended to use what they learned in the coming year.
7. 50 DE farmers (some continuing, others new) implement refined field plans to test tarping and RT practices on farm (Oct ‘21).
We followed up with all attendees from our in-person 2019 workshops (112) as well as those that attended our farmer-to-farmer webinar series offered earlier in the year (151). We emailed these farmers a short, online survey that asked them to share and reflect on how they used tarps in the previous year. We reached 23 farmers through this survey (about 10% of event attendees), where they shared how they used tarps, what benefits they found, any issues or concerns that they had and if they are planning to try it again next year. Common on-farm applications trialed (Year 2 Applications) included overwinter tarping for early spring crops (e.g., onions and greens), mid-season tarping ahead of fall crops including carrots, brassicas and greens, killing cover crops like rye and vetch, tarping in high tunnels targeting winter annual weeds, and full season applications to help suppress perennials or kill sod. Across all of these applications, they shared that tarping provided a number of benefits when compared to untarped beds and/or previous management, including:
- Less tillage. 52% used less intense tillage (e.g. shallower or gentler tools) and 62% made fewer tillage passes.
- Greater flexibility in field management. 76% found tarps helped hold beds weed-free until needed and 33% found tarps helped with spring field access.
- Better weed management. 91% found fewer weeds with 86% spending less time hand weeding.
- Improvements in crop establishment and yields. 48% found better soil conditions for planting (e.g. moisture, tilth) and 33% found better crop yields.
Farmers also shared their challenges (Year 2 Problems) which included keeping tarps secure from the wind, finding the time and labor to move them around especially when they are wet and/or in the middle of the season, creating habitat for voles, and persistent weeds, often perennials. Based on these reflections, 59% of farmers will definitely implement the same practice in the next year and another 36% will implement the practice again with some changes to improve on it. We plan to use individual email follow-ups to learn more details about these farmer practices, discuss ideas and questions, and maintain communications about future plans into the coming year.
In NY, we also actively collaborated with 3 farms to support on-farm experimentation with tarping and trialing of new practices. Partner farms/organizations, trial goals and outcomes included:
Van Noble Farms, Trumansburg, NY. Devon Van Noble manages a pastured pig operation and catering business and has recently added small fields for vegetable production. Van Noble was interested in trialing tarps to hold beds after early spring tillage and control weeds ahead of planting. A field was harrowed and tarped for 4 weeks in advance of planting potatoes in mid-May. After tarps were removed, beds were subsoiled with a tractor-led Keyline plow to create furrows for planting. Neighboring untarped beds required additional tillage passes and were difficult to access given the wet and cool spring conditions (Photo - Tarping at Van Noble). In the future, Van Noble plans to experiment with tarping overwinter to improve spring field access in his heavy soils.
Nook and Cranny Farm, Brooktondale, NY. Bob Tuori owns and operates a 4-acre diversified farm that uses a permanent bed system, walk behind tractor tools, and organic mulch for weed control. With funding from a 2021 Northeast SARE Farmer Grant, we designed an on-farm experiment to trial tarping prior to planting potatoes. Tuori has developed a potato production system that includes seeding cereal rye in fall, flail mowing rye in spring, strip tilling furrows (rotary harrow) for planting, and hilling and mulching with hay at 3-4 weeks after planting. The goal was to trial tarping (3-4 weeks in spring) as a tool to terminate a cereal rye cover crop, enhance weed suppression in the potatoes, and increase soil nutrient availability and potato crop yield (Photo - Tarping at Nook and Cranny). Three systems were compared: 1) mulched, standard practice 2) tarped 3) tarped and mulched. Results showed that tarping: 1) effectively killed and suppressed cereal rye relative to the untarped, mulch treatment, 2) provided little to no additional weed control benefits given the dominance of perennials, and 3) increased crop yield in one mid-season potato variety which was associated with greater soil nitrate concentrations. Tuori plans to implement the tarping and mulch practice for future potato production and is experimenting with other tarping applications on the farm, including using them in high tunnels to suppress winter annual weeds for early spring greens and carrot production.
Matthew 25 Farm, Lafayette, NY. We partnered with Kayo Green (Cornell Cooperative Extension-Onondaga) to implement a tarping demonstration and workshop for 4 incubator farmers in the Syracuse Refugee Agricultural Program (SyRAP) program. Neighboring beds were prepared with contrasting tillage tools (rototilled, shallow tilled, no-till) prior to applying a tarp in mid-summer. The tarp was removed, and a summer cover crop mix was seeded across the tarped area. This was a participatory workshop where farmers were introduced to the concept of tarping and how it can be used for bed preparation and improved weed control. Farmers helped remove the tarp, broadcast the cover crop, and rake beds. The host farm struggles with perennial weeds, especially yellow nutsedge, and the demonstration was specifically designed to learn if and how tarps can be used to help suppress and weaken perennial weeds.
8. 100 additional farmers improve their understanding of tarping and reduced tillage management practices based upon research results shared at on-station field days. One year of research data will be shared with participants.
We changed our plans for organizing and hosting a research station field day and tour our experiment in 2021 due to restrictions and uncertainties in hosting events during the COVID-19 pandemic. Our goal is to host an in-person field day in late summer or early fall 2022. During the 2021 field season, we shared field research updates with farmers with biweekly to monthly posts on Cornell Small Farms Program on Instagram (@CornellSmallFarms) and compiled these photos and field updates into an article "Reduced Tillage Research in Photos" featured in the Small Farms Quarterly magazine (Fall 2021 edition; 40,000 readership).
9. 100 additional farmers report knowledge gained on reduced tillage and tarping practices through winter conferences (Feb ‘22). Several DE farmers speak at meetings and describe farm management changes based on experience with on-farm trials. Two years of research data will be shared.
We have continued to share our research results with 387 farmers and agricultural service providers across the Northeast region through a combination of 5 virtual events in 2021-22, including specialized trainings and conference workshops. To date, these events and activities have included:
- Maher, R. Tarping research in organic vegetables. 02/10/21. Glynwood Center for Regional Food and Farming. No-till roundtable. Webinar. 25 farmers. 1hr.
- Maher, R. Reduced tillage strategies for organic vegetables. 04/09/21. Cornell Soil Health Program and American Farmland Trust – Soil Health Specialist Training. Webinar. 27 educators. 1 hr.
- Maher, R. Reduced tillage strategies for organic vegetables. 04/15/21. NRCS - NY Organic Ag Training. Webinar. 45 educators. 1 hr.
- Maher, R. Tarping Research Roundtable. Tillage Reduction Innovations Session. 12/13/21. New England Vegetable and Fruit Conference. Webinar. 290 farmers and educators. 0.25 hr.
- Ginakes, P. Using Permanent Beds in Combination with Different Mulching Strategies and Tarping to Improve Soil Health and Crop Yield: A Work In Progress. Soil Health Session, 12/15/21. New England Vegetable and Fruit Conference. Webinar. 230 farmers and educators. 0.25 hr.
10. 40 DE farmers report on changes to their management, labor use and profitability based upon onfarm trial findings via surveys and phone interviews (Nov ‘22).
Milestone Activities and Participation Summary
November 2019. We offered 3 full day workshops that combined researchers and invited farmer presentations followed small group breakouts/activities based on topic. Workshops were designed and facilitated used a Dialogue Education (DE) approach to engage farmers in new information/ideas followed by facilitated small group discussion to integrate ideas, share concerns, and identify additional information needed. We began each workshop with an inventory of current tarping practices/goals and prioritizing issues to discuss through the day and ended with an exercise to outline a farm-specific management change using tarps. In evaluations, all participants were asked to characterize their knowledge before and after the workshop based on five tarping topics: 1) logistics, 2) reducing tillage, 3) weed management, 4) soil building with cover crop, mulch and/or compost and 5) planning for tarps in rotations.
March 2021. We hosted 3 farmer-to-farmer webinars designed to share and learn about tarping practices that are being used on farm. Webinar speakers and topics were chosen based on feedback from previous trainings and year-end communications with DE workshop attendees. Each one hour webinar featured 2 farmer speakers followed by time for discussion and questions. After each webinar, farmers were directed to an online evaluation to provide us with feedback and knowledge gained. They were asked to share how much knowledge they had prior to the webinar and how much new information they learned on a range of tarping topics, including: 1) how to source tarps to fit the application and/or the farm, 2) how to handle the logistics of tarping, 3) how to plan for tarping in the crop rotation, 4) how to use tarps as a weed management tool, 5) how to reduce tillage with tarps, and 6) how to use tarps with cover crops.