Final report for LNE19-382
This project worked to increase the adoption of reduced-till (RT) and no-till (NT) practices to support the viability of small (<15 acres) and organically managed vegetable farms. These farms often face land constraints that can limit fallow periods and extensive cover cropping and need scale-appropriate RT and NT strategies to support soil health goals that work across a highly diversified crop mix, fit within their intensive rotations, and use labor efficiently. We investigated tarping as a low-cost RT and NT practice to benefit soils, reduce weeding labor, increase resilience to weather extremes, and lead to greater farm profitability. Using a long-term permanent bed experiment at two research locations (NY, ME), we investigated how tarping and mulching practices can improve the agronomics of organic RT and NT systems for a range of vegetable crop types, planting windows, and over continuous years. Tarping can overcome several NT production challenges by improving soil conditions for crop planting, reducing weeds for the following crop, adding labor efficiencies, and maintaining crop yields equivalent to conventional tillage systems. Organic mulching practices, including straw and compost, can facilitate NT adoption through legacy effects on soils that can lead to improve crop yields and greater weed suppression. Through a regional farmer survey (168 respondents) we gained a better understanding of the goals, logistical challenges, tillage practices, and weed management goals associated with tarping practices in the Northeast. Our educational approach, centered on farmer-to-farmer learning strategies, reached over a 1,000 farmers and educator participants, some attending multiple events, across the Northeast and combined intensive day-long trainings, conference workshops, webinars, on-farm trials, and field tours. Together with these training opportunities, we produced popular articles, website videos, and a practical guide, each sharing our research results and elevating successful farmers in sharing their practices and supporting others in trialing or modifying tarping applications on their farm. We developed a grower contact network of 240 farmers and documented how close to 60 farmers adopted tarping practices based on a range of soil and weed management benefits. Through continued engagement and feedback with these farmers, we showed that tarps can be used as an alternative to tillage, reducing both the number of tillage passes and the intensity of tillage needed for crop management across a range of farm applications. Farmers emphasized that tarping can provide greater management flexibility by holding beds between crops and increasing field access. They can also present logistical challenges and require planning for tarp application windows and strategies for streamlining tarp handling. Farmers have shown that tarps are a multifunctional management tool that can increase the adoption of RT and NT practices on small vegetable farms.
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 investigated black 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 was designed to use tarps to overcome commonly cited concerns with RT. Our research and extension team, which included our farmer advisors, brought together expertise across the Northeast region to take a whole-systems approach to advancing RT for these producers.
Our integrated research and education effort started with farmer-centered workshops using Dialogue Education (DE) strategies that facilitate peer-peer learning. Together, farmers identified opportunities for RT in their rotation, evaluated tarping strategies, and developed RT transition plans specific to their own goals. Subsequent farmer-led experimentation supported over multiple years through direct consulting, webinars, conference workshops, and field days helped farmers evaluate and share their results, participate in knowledge sharing networks, and learn research findings to foster continued innovation of these RT systems.
Using an established permanent bed systems trials (NY, ME) with a history of different soil and crop management regimes, our research explored how tarping, tillage and additional soil management practices changed 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, compost mulch; Obj. 2).
We used a systems approach to investigate the effects of tarping, tillage, and organic mulches 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). Research was conducted within 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 included: 1) unmulched, bare soil 2) oat straw (ME) or rye mulch (NY) applied at 5-6 tons per acre; and 3) compost mulch (manure-based, locally sourced) applied at 3-4cm 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 included 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 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 was to understand how tarping changes soils, weed dynamics, crop performance, and 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 mixture 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 mulch 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: 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 mix 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: We used a comprehensive set of field measurements to evaluate tarp and tillage system effects on soils, weeds, labor, and crop yields in 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. 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). Total 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 was analyzed for tillage system effects (tillage/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, 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 practices: 1) unmulched, bare soil 2) straw/rye hay mulch and 3) historic compost mulch.
Field Management: Straw/rye hay mulch that was applied the previous year (2019), was 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. In NY, rye hay mulch (5-6 tons per acre) was applied to the broccoli crop after the first cultivation (Photo - Applied mulch). No mulch was applied to broccoli in Maine. Compost mulch applications in previous years of this experiment resulted in over-accumulation of soil nutrients; the legacy of this practice was being examined. A moderate compost rate (5-6 tons/ac) was applied to all 3 treatments in 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.
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 analyzed data for mulch and tillage system (tillage/tarping) by mulch interactions.
We compiled our results across both locations (NY and ME) and all crops in the two-year rotation: beets and oat-pea cover crop (Yr 1/2020) and lettuce and broccoli (Yr 2/2021). We assessed tillage system (tillage and tarping) and mulch effects on soil conditions at crop planting, weeds throughout the season, including weed emergence in the crop and weeds at crop harvest, and marketable crop yields.
Effects on soil conditions at crop planting
No till systems are often associated with having cool, wet, and lower fertility soils than tilled soils, particularly in early spring. We found tarps increased soil temperatures by an average of 3-6℉ depending on the season. Our results from the spring (pre-lettuce) and summer (pre-broccoli) show how tarps drive changes in soil temperatures (Figure - Soil Temperature under Tarps). In the spring (April to May), this soil warming was primarily due to greater minimum soil temperatures rather than maximum temperatures. In the summer (July), tarps increased both maximum and minimum temperatures. These temperature changes add up when tarps are applied over 3-4 weeks; we found they increased total soil degree days (base 40°F) by 17-22%. The impermeability of tarps also regulates soil moisture conditions by excluding rainfall. We found that tarps maintained relatively constant soil moisture over the tarping period and that tilled soils dried out more quickly (Figure - Soil Moisture under Tarps). In dry summers, NT and tarping could be used to conserve soil moisture prior to planting. These changes in the soil environment are likely to affect soil biological activity, the availability of soil nutrients for the following crop, and crop establishment. We focused on documenting changes in plant-available soil nitrogen (N) after tarps were removed, at the time of crop planting.
Beets (Yr 1). We found tarps increased soil N available for the following crop (Figure - Soil N in Beets by Tillage System; Different letters above bars indicates significant differences between treatments). In NY, tarps increased soil N when applied in both tilled and no-till applications. Tarping led to twice as much soil N in NT and almost 3 times more in tilled systems. In Yr 1, tarps had been applied overwinter, from late fall after the previous broccoli crop (Nov) and through spring prior to planting beets (May). A long duration tarp could conserve mobile nitrogen that would otherwise be at risk to leaching, especially when soils are exposed to snow and rainfall events. However, we did not find the same effect in ME, so this trend was not consistent at both farm sites. We also found that mulching practices can drive changes in soil N (Figure - Soil N by Mulch in Beets; Different letters above bars indicates significant differences between treatments). Compost mulch had greater soil N than either no mulch or straw mulch in both NY (47% increase) and ME (37% increase). This result is likely driven by the greater soil organic matter concentrations that we have documented in compost mulched soils. We expected to find the lowest soil N concentrations in soils with straw mulch based on the potential for immobilization with high C:N residues on the soil surface. This was not the case, which could be attributed to our practice of raking straw out of planting beds into pathways prior to tillage and planting, thereby minimizing the incorporation of these residues.
Lettuce/Broccoli (Yr 2). In NY, we found similar trends to beets within a spring lettuce crop where tarps were applied for a shorter duration, 3-4 weeks, prior to planting. Tarping over tilled beds led to 2-3 times greater soil N than in their untarped counterparts, and had the same effect in NT, albeit to a lesser extent (50% increase) (Figure - Soil N in Lettuce and Broccoli by Tillage System; Different letters above bars indicates significant differences between treatments). Results from ME also showed that tarped soils had greater soil N prior to lettuce, though this was limited to soils with a legacy of compost mulch. Our results prior to planting broccoli showed how tarps can change soil conditions for planting when applied in a mid-season application, for a 3-4 week period between crops. When tillage was combined with tarping, we generally found greater soil N levels than when tarps or tillage were used alone. We found the highest concentrations when tarps were combined with tillage and the most consistent effect in compost mulch, where soil N increased by 1.7 to 2 times depending on location. (Figure - Soil N in Lettuce and Broccoli by Mulch; Different letters above bars indicates significant differences between treatments). This suggests that greater soil N in tilled and tarped soils is likely the combined result of mineralization stimulated by tillage and protection from leaching in rain events.
Overall, our results show that tarps can lead to greater soil N availability for the following crop across different tarp application times (overwinter, spring, and summer). This nitrogen could improve crop establishment and has the potential to reduce early fertilizer nitrogen needs. However, this nitrogen is also not synchronized with peak crop demand, so it may still be susceptible to leaching out of the crop root zone or have other undesirable consequences, including increasing weed competition. Tarping also has a large effect on soil N availability when applied over compost mulched soils. When timing does not allow for cover cropping and active root growth, maintaining soil cover with tarps could be an important strategy for farmers to conserve nutrients in these highly amended soils.
Effects on Weeds
Weeds at seedbed preparation. Repeated tillage events are typically required to kill weeds and prepare the seedbed for planting. In both shallow and deep tillage treatments, we used multiple tillage passes over the course of several weeks give to suppress winter annual weeds. We found that tarping after tillage helped terminate these living weeds and reduced the number of tillage passes that were necessary prior to planting (from 2-3 times to 1). Tarps also effectively killed living annual weeds in NT beds, enabling planting into weed-free conditions with no soil disturbance. We found significant hand labor was invested in pulling and removing weeds prior to planting in NT without a tarp, which contributes to a significant portion of the total labor hours for the crop. While the logistics of tarping, including securing tarps and moving sandbags, requires hand labor, our data on total labor hours suggests that tarps could reduce total labor for NT by 20-30%, resulting in similar labor investments to conventional, deep tillage. In ME (Yr 1), we found weed pressure in NT can be so high that it does not justify planting a 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 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 reduce weed emergence in the following crop. Often white thread weeds can be seen emerging under tarps. Tarps may promote fatal seed germination by creating warm, moist soil conditions that promote weed germination and subsequent death by excluding light. When soils are not disturbed after tarp removal, this could leave fewer weed seeds to emerge and compete with the following crop. In a beet crop 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%. We found similar results in Yr 2 of the rotation (Figure - Mid-Season Weeds in Lettuce and Broccoli by Tillage System; Different letters above bars indicates significant differences between treatments). Tarping with deep tillage 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 to a lesser degree and with less consistently across locations and crops. In ME, this reduction was as great as 86% in beets and 76% in lettuce, and in NY the reduction was only significant for broccoli (73% lower). Tarp effects on the weed seedbank are likely species-specific. In NY, common chickweed was the dominant winter annual weed and hairy galinsoga was the dominant summer annual. In ME, common lambsquarters, redroot pigweed, and witchgrass were dominant weed species.
Surprisingly, we found weed counts in the crop were similar between NT and NT with tarping and there were no differences in any crop or location (excluding beet crop in ME). This suggests that with persistent hand weeding in NT and notably higher labor investments to prepare beds, we achieved equivalent early season weed control in the crop in NT with or without tarping. This result also shows that early season weed pressure likely did 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 between these treatments, 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 seeds, and 3) by facilitating NT, they minimize 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 our assessment of weeds at the time of harvest, though variability among treatments led to few measurable differences (Figure - Weeds at Beet Harvest by Tillage System, No data on weed biomass in Maine; Different letters above bars indicates significant differences between treatments). We used weed counts weeds above the crop canopy as an indicator the large, crop-competitive weeds. In beets, we 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 Lettuce and Broccoli Harvest by Tillage System; Different letters above bars indicates significant differences between treatments). This is likely 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 establishment of 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. In NY, there was heavy early spring weed cover in tilled beds prior to spring tillage events, 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, contributing 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 firm seedbed that likely improved soil conditions for beet germination and establishment. Straw mulch that was applied to the previous broccoli crop and left in place overwinter also effectively suppressed these winter annual weeds. After raking mulch into pathways, we inherited weed free conditions prior to tillage and planting. This likely contributed to greater beet stands in straw mulch, where we found a 45-85% increase compared to bare ground. 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 mulch. Compost mulch beds have been shown to be much lighter with lower bulk density, especially at the surface, and this may have 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 - Beet Yields by Tillage System; Different letters above bars indicates significant differences between treatments). We did find 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. Beet yields were consistently affected by the legacy of mulching and we found reduced beet yields in bare ground relative to both straw and compost mulch at both locations (Figure - Beet Yield by Mulch; Different letters above bars indicates significant differences between treatments). Compost mulch yielded greater than straw in NY while these mulch treatments were similar in ME.
Lettuce and Broccoli (Yr 2). Similar to beets, mulch legacy had a strong effect on lettuce and broccoli crop yields. In NY, compost and straw mulch increased lettuce yields compared to bare ground (Figure - Lettuce and Broccoli Yields by Mulch; Different letters above bars indicates significant differences between treatments). 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 provided equivalent yields to conventional deep tillage. We also found that mulching practices leave a management legacy that can increase crop yields. Compost mulch led to improved crop yields for multiple years after application, which could be attributed to the dramatic accumulation of soil organic matter and changes soil physical and biological processes. Straw mulch also had a legacy effect that increased crop yields in years after the mulch is applied. This is likely related to a combination of the the weed suppressive benefits of the mulch, which can carryover into successive crops, and improvements in soil conditions for planting (e.g. firm, moist seedbed).
Small farms need accessible, scale-appropriate tools and practices that overcome barriers to using less tillage. Our research showed that tarping can facilitate the adoption of continuous RT and NT practices across multiple crop types (direct seeded and transplanted) and planting times (spring and summer). Farmers can use tarps after tillage to hold beds and reduce additional field passes while improving seedbed conditions for planting. Tarps moderate soil moisture, increase plant available soil nitrogen, and reduce early season weed emergence in the following cash crop. Farmers that use tillage prior to tarping can expect the greatest impact on these soil processes. Elevated soil nitrogen could improve crop establishment and have the potential to reduce early fertilizer nitrogen needs. However, this nitrogen is also not synchronized with peak crop demand, so it may still be susceptible to leaching out of the crop root zone or have other undesirable consequences. When rotation timing does not allow for cover cropping and active root growth, maintaining soil cover with tarps could be also be a strategy for farmers to conserve soil nutrients, especially in highly amended soils. For farmers looking to adopt NT practices, tarps can create opportunities by consistently killing living annual weeds with no soil disturbance and reducing labor needs for bed preparation. These benefits are particularly valuable in direct seeded crops where weed management can be more challenging and organic mulches are not practical or appropriate. When applied in a NT rotation over consecutive years, tarps are likely to draw down the weed seedbank through a combination of factors, including promoting the fatal germination of weed seeds, holding beds at times when weeds would otherwise produce seed, and by minimizing the introduction of new weed seeds from greater soil depths. Tarping in NT can provide equivalent crop yields to conventional tillage practices; however organic mulching practices, including straw and compost, can lead to greater crop yields by providing additional soil and weed management benefits. These organic mulches have strong legacy effects, where the impacts of the practice can be seen in the following years and crops in the rotation. Farms with access to straw mulch and available labor should consider applying in select transplanted crops while farms with a history of compost mulch applications could consider reducing compost rates. Tarping can provide multifunctional benefits to reduce the barriers to RT and NT adoption for small-scale farms and should be combined with other soil-improving management practices to optimize benefits.
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. We developed an online survey (158 respondents) to learn 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 were 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 shared our research results and farmer lessons learned with over 800 farmers and educators (some attending multiple events) in the Northeast region through 16 additional presentations over 3 years, including conference workshops, winter meetings, and online trainings. In summer 2022, we hosted an on-station field day resulting in 40 additional farmers and educators improving their understanding of tarping and RT practices based upon research results. We synthesized on-farm experiences from almost 60 DE farmers and others engaged through webinars, field days, and on-farm demonstrations through online surveys and phone calls. We elevated farmer experiences and case studies through website resources, YouTube videos, popular articles (e.g., Small Farms Quarterly), and a comprehensive extension publication, Tarping in the Northeast: A Guide for Small Farms, that was produced with university and extension collaborators in the Northeast.
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 was 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 audience of farmers and educators through these workshops offered in 2019-2020:
- 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 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. 668 views, accessed Jan 17, 2023. 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. 873 views, accessed Jan 17, 2023. 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. 404 views, accessed Jan 17, 2023. 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.
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.
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, together 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. To elevate and share the results of this collaboration, we coauthored an article with Tuori titled To Tarp, to Mulch, or To Do Both - That Was the The Question that was published in the Small Farms Quarterly (Spring 2022 edition), an online and printed publication of the Cornell Small Farms Program (combined readership 40,000). We produced a video, On-farm Experimentation With Reduced Tillage: Tarping and Mulching in Potatoes, which was designed to accompany the article and highlight the process of on-farm experimentation. The video was posted on the Cornell Small Farm You Tube channel (594 views, accessed 1/18/2022).
8. 100 additional farmers improve their understanding of tarping and reduced tillage management practices based upon research results shared at on-station field days.
We changed our plans for organizing and hosting a research station field day in 2021 due to restrictions and uncertainties in hosting events during the COVID-19 pandemic. 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).
In the summer of 2022, we partnered with the New York Soil Health Program as part of their Soil Health and Climate Resiliency Field Day Series, https://www.newyorksoilhealth.org/fielddays/. One of these events was hosted at the Cornell Thompson Vegetable Research Farm in Freeville, NY, and was titled “Tools and Tactics for Soil and Weed Management in Vegetable Production” (July 25, 2022). It was attended by 40 farmers and educators who represented farm sizes from 0.5 to 20 acres. We shared research results on tarping practices and toured plots from our Long-Term Permanent Bed Experiment. We presented together with members of the Wickings Lab on Arthropod Ecology at Cornell, who spoke on the role and value of invertebrates in soils and our discussed new research directed towards measuring tarping impacts on the soil mesofauna community (Photo - Freeville Field Day). Evaluations (13 farmers) provided feedback on the quality of the presentations and how the event impacted the practices they were implementing on their farms. Ten farmers (77%) responded that they would try using tarps on their farm or would be changing the way that they utilize tarps, e.g., to terminate cover crops, reducing tillage, or plant earlier in the season. Overall evaluations scored very high for Knowledge Gained (4.5/5), Presentation Relevance (4.8/5), and for Presentation Style (4.7/5) and all respondents shared they would be interested in attending future field days.
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 shared our research results with farmers and agricultural service providers across the Northeast region through 10 virtual and in-person events from 2021-22, including specialized trainings, conference workshops, and field tours. These activities 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. 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. 0.25 hr.
- Maher, R. Tarping to reduce tillage in small-scale organic vegetables. 2/1/22. Mid- Atlantic Fruit and Vegetable Conference. Hershey, PA. Virtual. 30 farmers. 0.5 hr.
- Maher, R., Tuori, B. Using tarps to reduce tillage on small vegetable farms. 2/11/22. PASA Sustainable Agriculture Conference. Lancaster, PA. 60 farmers. 1 hr.
- Maher, R. Trials and tale of using tarps with reduced tillage and cover crops. 3/10/22. Northeast Cover Crops Conference. Virtual. 40 educators. 0.5 hr.
- Maher, R. Alvarado, M. Soil health and tarping in vegetables field tour (delivered in English and Spanish). 6/13/22. Tompkins Cortland Community College Dominican Republic Tour. Freeville, NY. 15 educators. 2 hrs.
- Maher, R. Salzl, M. Soil health and tarping in vegetables field tour. 9/13/22. NE SARE Fellows Tour. Freeville, NY. 15 educators. 2 hrs.
10. 40 DE farmers report on changes to their management, labor use and profitability based upon on-farm trial findings via surveys and phone interviews (Nov ‘22).
In the winter of 2022, we again followed up with farmers that participated in our project (240 individuals, including DE workshops and webinar participants) and shared a short, online survey that asked them to reflect on how tarps have changed their farm management over time. We reached 29 farmers through this survey, where they shared how they used tarps, what benefits they have found, any issues or concerns that they had and how they plan on using tarps in the future. For these farmers, farm size based on planted acres in vegetables, fruits, flowers, herbs ranged from 0.1 acres to 10 acres, with a mean of 2.6 acres. Farmers used tarps on 0.1 to 2 acres, which represented 5 to 100% of their planted acreage, with an average of 45% of acreage in production under tarps (0.7 acres). On average, surveyed farmers had been using tarps for four years with a range from 1 to 9 years.
Farmers were asked to specifically reflect on how tarping has led to changes in their soil, weed, crop, and overall farm management. They shared how tarps are used in both tilled and no-till applications, to create stale seed beds, to terminate cover crops, to create new planting areas, and as an overwinter cover crop substitute (Year 3 Applications). Based on this survey, farmers reported that using tarps led to a wide range of management changes (Year 3 Farmer Changes). These included:
- Reduced tillage. 93% of farmers used fewer tillage passes and 71% used less intensive tillage (e.g., shallower or gentler tools).
- Improved soil management. 36% found that tarps reduced water-related management problems and 39% found that tarps helped them implement more cover crops.
- Increased field management flexibility. 68% reported that tarps increased both field access and overall management flexibility.
- Enhanced weed management. 89% of farmers found tarps led to fewer weeds (including reductions in annual and perennial weeds) with 86% also reporting less weeding labor.
- Less labor. 68% found that tarps reduced both hand and equipment labor.
- Increased profitability. 54% reported increased farm profitability after using tarps.
Farmers also shared their challenges (Year 3 Challenges and Insights ) 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 a desire to reduce plastic use in agriculture. Based on their experiences, 33% of farmers will continue using tarps in the same manner while 43% of farmers are looking for new uses or ways to adapt tarps.
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.
July 2022. We hosted a field day at the NY research farm location to discuss research results from our Long-Term Permanent Bed Experiment. We shared results on tillage, tarping, and mulching practices and toured research plots. We presented within a 4 hour program together with other Cornell University researchers and extension. Farmers provided evaluations that gave provide feedback on the quality of the presentations, knowledge gained, and how each presentation would impact their practices on the farm.
Performance Target Outcomes
Adopting tarping practices
40 hours of labor and $1000 per tarped acre
Reduced tillage, greater field and crop management flexibility, labor savings, and an increase in farm profitability
Adopted tarping practices
0.1 to 2 acres per farm based on farm size
Reduced tillage (fewer tillage passes, less intensive tillage practices)
Improved soil management (better soil conditions for planting, improved water management, increased cover crop adoption)
Greater flexibility in field management (increased field access in spring, improved ability to hold beds weed-free)
Improved weed management (fewer weeds and less time spent hand weeding)
Improved crop yields
Less labor (reductions in hand and equipment labor)
Increased farm profitability
Our project goals were to support farmers in 1) learning how to use tarping to overcome barriers to reducing tillage in vegetables while improving soil and weed management and 2) identifying specific changes they can make to their farm management that will have measurable benefits to their farm management. We initiated this project with a series of intensive farmer-to-farmer workshops that laid the groundwork for supporting farmers in adopting new practices and informing the design of additional educational opportunities over the following two years, including farmer-to-farmer webinars, conference workshops, and field days. We supported farmers that attended these trainings over the course of the project through email, phone, resource sharing and research updates. We developed grower network list and used online surveys (winter of '20, 21, and '22) that asked farmers to describe what tarping practices they had implemented, how those practices had changed their management, specific challenges or modifications needed, and what further resources or information would support their tarping goals. Over three years, we reached a total of 240 farmers with these surveys and received responses from 59 individual farmers, some in multiple years. We asked farmers that had trialed tarping practices to share changes to soil and weed management, labor, crop yields, and profitability (see example Year 3 Farmer Changes, 28 farmers). For these farmers, farm size based on planted acres in vegetables, fruits, flowers, herbs ranged from 0.1 acres to 10 acres, with a mean of 2.6 acres. Farmers used tarps on 0.1 to 2 acres, which represented 5 to 100% of their planted acreage, with an average of 45% of acreage in production under tarps (0.7 acres). These surveys documented how the adoption or modification of tarping practices led to reduced tillage practices, as measured by fewer tillage passes and/or use of shallower or gentler tillage tools. Farmers reduced their hand labor which was associated with less annual and perennial weeds and less time spent weeding. Farmers also reported greater field management flexibility, primarily through improved field access and the ability to hold beds weed free between crops. Fewer farmers reported an increase in profitability when compared to these other benefits. We were unable to document a specific amount of labor hours reduced or change in net income associated with tarping practices alone. We found that tarps are a multifunctional management tool for small vegetable farms and that farmers were driven to make management changes based on range of tarping benefits.
Additional Project Outcomes
- Tarping in the Northeast: A Guide for Small Farms (Manual/Guide)
- Reserving Beds With Tarps: Setting The Table For When It’s Time To Plant (Webinar)
- Pairing Tarping With Cover Crops: Getting Both On The Menu. (Webinar)
- You Can’t Send Back Your Soils And Weeds: Tarping The Problems You’re Served (Webinar)