Final report for LNC19-417
Project Information
Towards Resilient and Sustainable Grape Production in the North Central Region with Renewable Mulching Systems: Freezing stress, which could damage plant parts or kill whole vines, is the main challenge of grape production in cold regions in the U.S., including the North Central Region (NCR) leading to crop and vine losses. Soil hilling is a standard and somewhat effective cold protection practice for preventing vine loss. However, its negative impact on the soil-vine environment is a continuing problem because it contributes to soil degradation and declining vine health. Plant-based mulching is an alternative winter protection method that has not been widely adopted due to the cost of mulch and unavailability of specialized equipment in the market for its application. We propose to solve this problem by accomplishing the following objectives: 1) evaluate the efficacy and horticultural and environmental benefits of different types of renewable biomass mulch, 2) develop a mechanized prototype for mulch delivery, 3) engage local growers, throughout the life of the project, with the development/testing of a sustainable mulching system in their vineyards, and 4) evaluate the cost effectiveness of locally grown plant species and new mulching system compared to soil hilling. All mulches used outperformed soil hilling in terms of winter protection. They also improved soil quality without reducing yield or fruit quality. We purchased a mechanized apparatus that delivered straw mulch. We enhanced producers’ knowledge and empowerment through multiple educational platforms. In the long-term, and due to its effectiveness, we predict that renewable biomass mulching will become an integral vineyard practice towards a resilient and sustainable grape production in the NCR.
Learning outcomes:
Growers learned about biomass mulches and their horticultural and environmental benefits through the following deliverables: 1) workshops/field days to educate about renewable biomass mulches and demonstrate a prototype for its application and 2) presentations at the annual Ohio Grape & Wine Conference (in 2021 and 2022)
Action outcomes:
- Growers will use mulching and increase profits by reducing negative impacts on soil and vine productivity.
- Growers will be confident to adopt mulching with the gained knowledge of its cost-benefit.
Economic importance of grape and impact of cold damage on the industry: Grapes are the most valuable horticultural crop in the U.S., with a farm gate value of more than $6 billion (www.nass.usda.gov). The grape-wine industry in NCR has expanded rapidly in recent years with >1,000 wineries and annual economic impact of >$5 billion. Growing interest in this cash crop is driven by the steady increase of wine consumption in the U.S. (www.wineinstitute.org), the high value of winegrapes as an alternative and profitable crop in the NCR (Dami et al. 2005), and its adaptability to lands that are unsuitable for row crop production. The continued success of this industry relies on a sustainable grape production by mitigating crop/vine loss due to cold damage. In the U.S., cold damage is by far the most devastating weather event to fruit production, accounting for an average of $250 million/year of insurance payments for crop loss to grape and fruit growers (www.rma.usda.gov). In Ohio, grape growers have experienced major consecutive freezing damage episodes over the last ten years with unprecedented crop losses valued at $12 million following the “polar vortex” event in 2014 (Dami and Lewis 2014).
Winter protection by soil hilling and its limitations: To prevent complete vine loss, and due to its insulating properties, hilling with soil is cost-effective and has been the industry standard for winter protection for decades (Zabadal et al., 2007). Though effective for winter protection, soil hilling has several agricultural concerns involving its negative impacts on grapevine health. Plows can cause direct mechanical trunk damage, increasing disease susceptibility (Zabadal et al., 2007). It can also lead to excessive root pruning thus restrict root growth, reduce nutrient availability, and result in scion rooting. Higher weed pressure has also been correlated with soil hilling (Jiang et al., 2008). The repeated practices of soil hilling and de-hilling (removing hilled soil from vines in the spring) is destructive to soil physical, chemical, and biological features. It increases soil erosion and nutrient/pesticide runoff potential (Fu et al., 2006). It collapses soil pores resulting in compacted soil which restricts root growth and access to water and nutrients, and decreases water infiltration leading to ponding of water and damaged roots (Alspach, n.d., Zabadal et al., 2007).
Mulching in vineyards & soil quality: Unlike soil hilling, mulching adds organic matter, physically protects the soil, and intercepts soil contaminants which increases soil quality. This study will focus on several indicators of soil quality including soil organic matter, compaction, and water infiltration. Soil organic matter (SOM) is a major contributor to soil quality. It increases the cation exchange capacity of the soil, stabilizes soil aggregation, enhances soil water holding capacity and the ability to adsorb pesticides and other pollutants (Cooperband, 2002). SOM also supports soil trophic complexity which can have plant growth promoting, disease suppressing, and carbon sequestering effects (Moebius-Clune et al., 2016). Straw and other alternatives also reduce erosion by intercepting falling raindrops. Additionally, mulches were found to buffer temperatures as much as 12 °C higher than air temperatures (Zabadal et al., 2007) which effectively protects susceptible grapevine parts.
Mulches in vineyards have been shown to suppress weeds, retain moisture, enable nutrient release, increase organic matter, and increase yeast available nitrogen in grape juice (Agnew et al., 2001). DeVetter et al. (2015) evaluated four weed management strategies and found that straw mulch-treated soils had higher water content, organic matter, aggregate stability and biological activity, and reduced weed populations. Plant-based mulching is not new and has been tested as an alternate winter protection method. However, mulch has not been widely adopted due to its cost and the unavailability of specialized equipment for application. Commercial mulchers are primarily used for fertilizer application, are not designed for winter protection, and are not cost effective for small vineyards (<10 acres) in the NCR.
Cooperators
Research
Project Objectives
- Evaluate the efficacy and horticultural and environmental benefits of different types of renewable biomass mulch
- Engaging local growers throughout the project with the development/testing of a sustainable mulching system in their vineyards
- Evaluating the cost effectiveness of locally grown plant species and new mulching system compared to soil hilling
In Year 3, we have addressed all above three objectives and accomplishments are summarized below.
1. Evaluation of the Efficacy and Horticultural and Environmental Benefits of Different Types of Renewable Biomass Mulch
Experimental Sites and Treatments:
Two locations were used for this trial, one at the OSU research vineyard and the other at a commercial vineyard.
To determine the efficacy of different types of renewable biomass, plant-based mulches were acquired and tested. Aloterra, an industry partner, provided Miscanthus for evaluation against commonly known mulches of Wheat Straw and Corn Stover in comparison to the conventional winter protection method of Soil Hilling to determine mulching impacts on grapevine physiology (growth, yield, fruit quality), health (crown gall incidence, scion rooting), and soil quality (moisture, compaction, infiltration, health indicators). Wheat Straw was used from small rectangular bales. Corn Stover was used from grinding round bales to a 1” particle size. Miscanthus was categorized into ‘chopped’ (~1” particle size) and ‘fine’ (< 1/4” particle size) and used at different experimental sites. All three different types of mulch were sent for Compost Analysis at a commercial laboratory to determine their nutrient content prior to application. Thus, the different mulch and soil treatments for the study included: Wheat Straw, Miscanthus (chopped), Miscanthus (fine), Corn Stover, and Soil Hill. Three treatments (Wheat Straw, Miscanthus, and Soil Hill) were used at the Geneva vineyard.
The grapevine rows at the commercial site were spaced 9 ft between the rows and 4 ft between the vines. The mulch and soil treatments were applied in November 2019. The mulch treatments were applied in mounds of 8” height, 2 ft around each vine and spread out at a height of around 3” in between the vines through an entire panel (Figures 1). Wheat Straw was applied from the small bales: 8” was removed from the bale along the bale length and was applied on either side of the graft union and 3” was applied in between the vines. Care was taken to spread the wheat straw in order to cover the graft unions as the mulch was applied from bales which were not shredded.
The amount of mulch applied for each treatment replicate was noted to conduct an economic impact analysis of the mulching method for winter protection as well as to determine the amount of mulch that needs to be reapplied for the following year after conducting a mulch height analysis on the amount mulch that receded through the winter.
Mulching Impact on Soil Environment:
Figure 2. Installation of temperature sensors in Wheat Straw
Soil Moisture: A time-domain reflectometer (TDR) soil moisture meter (Spectrum Technologies, Inc., Aurora, IL) was used to measure soil moisture at approximately 2” depth increments in 2022. The soil moisture meter probes were inserted in the soil under the mulch covers as well as de-hilled soil approximately 6” from the graft unions. The probes were capable of recording soil moisture content at 1.5”, 3”, 4.8” and 8” below the ground level. At least three observations of soil moisture at each depth were recorded for each treatment-replicate.
Infiltration: Soil infiltration rate (unsaturated hydraulic conductivity) was measured in 2022. The mini-disk infiltrometer was placed on the soil under the mulch covers and de-hilled soil, approximately 6” from the graft unions, and the amount of water infiltrated was recorded with respect to time for each treatment (Zhang, R. (1997). The suction on the mini-disk infiltrometer was adjusted according to the rate of infiltration. The cumulative infiltration was plotted against the square root of time and a hydraulic conductivity (K) value was determined taking into consideration the respective parameters for the soil type from Van Genuchten tables (Dane et al., 2002; Dohnal et al., 2010). The soil type was classified as silty clay loam for the experimental site. One measurement was made with the mini-disk infiltrometer per each treatment replicate.
Soil Compaction: Surface and subsurface hardness was measured in 2022 at 2” intervals of depth when the soil was at field capacity (approximately 48 hours following a soaking rain event) using a FieldScout field penetrometer (Spectrum Technologies, Inc., Aurora, IL). The soil compaction field penetrometer probe was inserted in the soil under the mulch covers as well as de-hilled soil approximately 6” from the graft unions in order to record the soil hardness at a certain depth. The probe was capable of recording soil compaction at 2” depth intervals. One observation of soil compaction was made for each treatment replicate up to 16” depth. A 1/2” cone was used for all measurements.
Tissue Nutrients: Tissue nutrients were determined by analyzing the nutrient content in petioles. A total of 60 petioles per treatment-replicate were collected during the summer of 2022 at approximately 80% veraison for the Cabernet Franc variety at Ferrante and sent for nutrient content analysis at a commercial lab.
Soil Nutrients: Soil samples of approximately 1 lb. per treatment replicate (~1/4 lb. per randomly selected vine) were collected using a soil probe (JMC Soil Samplers, Newton, IA), the samples consisting of soil profiles up to 8” depth below the ground level collected at approximately 6” distance from the grapevine. Soil samples were collected in Fall 2022 and were sent to Brookside Labs (New Bremen, OH) for standard nutrient analysis (pH, Cation Exchange Capacity, macronutrients, and micronutrients). Soil macro-nutrients along with the cation exchange capacity (which measures the soil’s ability to supply Ca, Mg, and K nutrients) will be shared in the final report.
Soil Health: Active Soil Organic Matter (SOM) was measured through soil respiration, soil protein and active carbon analyses. Collectively these measurements provide insight into biologically-driven C and N dynamics in the soil.
Mulching Impact on Weeds and Grapevine Physiology:
Weed Infestation: A thorough weed study was conducted in Summer 2022 at Ferrante. Weed cover percentage was estimated in the 3-ft wide vine rows between the first and last vine of each treatment replicate which included two panels of 24 ft each based on the amount of area that was under weed cover. Weed biomass was harvested in eight 1/4 m2 quadrats centered in each row for each treatment replicate around vines 1, 2, 3 and 4 in each panel in order to measure ‘around-vine’ weed biomass. Weed biomass was also harvested in eight 1/4 m2 quadrats centered in each row and placed in between vines 1-2, 2-3, 3-4 and 4-5 in each of the two panels for each treatment replicate in order to measure ‘inter-vine’ weed biomass.
Yield: Vine yield was measured at harvest time. The yield components consisted of collecting and recording cluster count per vine, crop weight per vine, and 100-berry weight for each treatment-replicate. Regent was harvested in October 2022 and the yield components data were collected for at least three observations per treatment-replicate at OSU vineyard.
Fruit Quality: Fruit quality was determined by crushing 100 berry samples and measuring juice sugars, pH and acidity. The 100 berry samples were collected from each treatment replicate at the time of harvest in October 2022.
Mulch Replenishment (Mulch Height):
In order to reduce cost of annual mulch application, we did not remove the mulches after winter, like is the case with soil (dehilling). Instead, we kept the mulches for the third season. However, w recorded how much was lost by measuring the mulch mound height. using a pair of 3 ft steel rulers.
3. Engaging Local Growers with Project Execution:
Grower’s willingness to adopt a methodology will be assessed via a researcher developed questionnaire. The questionnaire will measure a grower’s perceptions of the innovation. Potential adopters of the technology will complete the questionnaire before engaging in the development process.
Soil Health_Regent_2022-2023Soil Health_Regent_2022-2023 GIESCO 2023 - Mulching Study Poster_48 x 36_DRAFT_ID
References
Almajmaie, A., Hardie, M., Acuna, T., & Birch, C. (2017). Evaluation of methods for determining soil aggregate stability. Soil and tillage research, 167, 39-45.
Dami, I., Bordelon, B., Ferree, D. C., Brown, M., Ellis, M. A., Williams, R. N., & Doohan, D. (2005). Midwest grape production guide. Bulletin 919. Columbus: The Ohio State University Extension.
Dane, J. H., & Topp, C. G. (Eds.). (2020). Methods of soil analysis, Part 4: Physical methods (Vol. 20). John Wiley & Sons.
Dohnal, M., Dusek, J., & Vogel, T. (2010). Improving hydraulic conductivity estimates from minidisk infiltrometer measurements for soils with wide pore‐size distributions. Soil Science Society of America Journal, 74(3), 804-811.
Fine, A. K., van Es, H. M., & Schindelbeck, R. R. (2017). Statistics, scoring functions, and regional analysis of a comprehensive soil health database. Soil Science Society of America Journal, 81(3), 589-601.
Hurisso, T. T., Culman, S. W., Horwath, W. R., Wade, J., Cass, D., Beniston, J. W., ... & Ugarte, C. M. (2016). Comparison of permanganate‐oxidizable carbon and mineralizable carbon for assessment of organic matter stabilization and mineralization. Soil Science Society of America Journal, 80(5), 1352-1364.
Mikha, M.M., and C.W. Rice. 2004. Tillage and manure effects on soil and aggregate-associated carbon and nitrogen. Soil Sci. Soc. Am. J. 68(3):809–816.
Sundermeier A.P., and Shedekar, V.S. soil aggregate stability – a soil health physical indicator. C.O.R.N. Newsletter (2018-02), 2/21/2018.
Wolf, T.K. (2008). Wine Grape Production Guide for Eastern North America. Natural Resource Agriculture and Engineering, Ithaca, NY.
Zabadal, T.J., Dami, I.E., Goffinet, M.C., Martinson, T.E., Chien, M.L. (2007). Winter injury to grapevines and methods of protection. Extension Bulletin E 2030, 106.
Zhang, R. (1997). Determination of soil sorptivity and hydraulic conductivity from the disk infiltrometer. Soil Science Society of America Journal, 61(4), 1024-1030.
All mulches used were effective to provide winter protection. Some worked better than others. The size of mulch particles is critical. We found 1" particles worked well. Mulches improved soil physical and biological properties compared to soil hilling. There was no negative effect on yield or fruit quality. All mulches suppressed all weeds (especially annuals) and weed control lasted for two years. Cost is more effective when mulch is applied every other year.
Education
17 February 2020: Organized a focus group meeting and presented “Novel delivery system for vineyard mulching” at the Ohio Grape & Wine Conference, held in Dublin, Ohio. There were 15 in attendance representing grape growers that own/manage different size vineyards. The purpose of the meeting was to introduce the project and topic of vineyard mulching with focus on gathering feedback from stakeholders on developing a mulching prototype.
5 March 2020: Presented a project update titled: “Vineyard mulching: Is it worth it?” at the Northeast Ohio Winter Grape School hosted by Stonegait Winery, Madison, OH. There were 35 attendees, most were grape growers. This educational event was held in-person, just prior to the state-lockdown due to COVID pandemic. The purpose of the presentation was to educate about the topic of mulching in vineyards and introduce the project.
4 March 2021: Presented an update about the project titled: "Vineyard Mulching Project Research Update" at the OSU Winter Grape School. Due to COVID, this Zoom educational event was virtual. There were 38 attendees, most were grape growers. Preliminary findings of the mulching project were shared.
June 2022: Presented a project update titled: "Vineyard Mulching: Impact on Vine Growth, Yield, and Fruit Quality" This was one presentation in a Webinar series titled:" Vineyard Mulching: Benefits beyond Winter Protection". 40 in attendance.
August 2022: Presented a project update and conducted a mulching demonstration: "Vineyard Mulching Demonstration" at Ferrante Vineyard and OSU-AARS in Kingsville, Ohio. 40 were in attendance.
July 2023: Presented a poster titled:"Vineyard Mulching Offers Many Benefits Beyond Winter Protection". at an int'l conference, GIESCO held at Cornell University, NY. Nearly 250 in attendance.
Project Activities
Educational & Outreach Activities
Participation Summary:
sharing info on project results
Learning Outcomes
- Impact of mulching on winter protection of graft union
- Benefits of vineyard mulching on weed control
- Benefits of vineyard mulching on water conservation
- Benefits of vineyard mulching on water infiltration
- Benefits of vineyard mulching on soil compaction
- Mulching and yield
- Mulching and fruit quality
- Benefits of vineyard mulching on soil health
- Types of renewable biomass products as mulch
- Mechanization of vineyard mulching
Project Outcomes
Adopting mulching, farmers would improve weed control, water conservation and infiltration, soil compactness, and soil health
In 2023, a grape grower in northeast Ohio tried straw mulch for the first time in his vineyard based on our project. We shared our temperature sensors to monitor temperature inside the mulch during winter.
We recommend testing more mulching materials that are cost effective, readily available, and sustainable. More research needed to identify or fabricate a cost effective mulcher. This was beyond the scope of this project. Long-term studies (5+ years) are needed to determine soil health benefits.