Another season comes to an end. Over the next few months we will be analyzing the data from this season, comparing it to lasts and contemplating the results. We will post our summaries on this blog as soon as we have them available.

The is the merlot in the research vineyard after harvest and just before all the leaves came off.

Harvest couldn't have been better. The weather cooperated this year (thankfully no tropical storms) but it didn't stop us from running around trying to get all the data we needed before the fruit came off at our grower cooperator sites. Here are a few pictures of harvest at Martha Clara where we needed to take a bit more data because the plots were replicated.

Here is before and after the syrah vines were picked.

We want to thank not only all of our cooperators for allowing us to come take data this season and allowing us to continue this work through the next but also the people who came out to help us pick and take data. It's a lot of work that needs to be done in a short window and everyone did a great job. THANKS!

Bird netting on Merlot at the research vineyard - that time of year again.

Almost all varieties are in veraison this week so many vineyards are getting their nets on. We needed to get a bit of data before that happened so have been out in our trial blocks the beginning part of this week. Here are a few shots of under trellis cover crops in August.

 Bedell clover starting to die back and Merlot in veraison. 

Old Field Vineyard using a low growing fescue next to vines that had herbicide for comparison.

These last two photos are of Duck Walk using dutch white clover.

Here is another interview conducted by CCE-SC summer intern Matt Gura. He interviewed Barbara Shinn about her experiences with under trellis mowing at Shinn Estate Vineyards.

I spoke with Barbara Shinn, owner and vineyard manager at Shinn Estate Vineyards, about her thoughts on under-vine covers.  She has been maintaining an under-vine cover crop for just short of a decade now.  This was not always the case: “We began maintaining under-trellis cover in all earnest in 2004, 4 years after we began planting the vineyard. At first we kept the growth mowed very low throughout the growing season believing that aggressive growth under the vines may prove unmanageable and hinder air flow. Now we understand the rhythm of our vineyard meadow.”  Shinn Estates utilizes a custom built under-vine mower to strike a balance between controlling aggressive weeds penetrating the fruit zone while remaining concurrent with her biodynamic approach to management : “We mow twice in quick succession in April and May then mow only once in June, July and August for a total of 5 mowings per year. The important issue is timing the mowings in unison with the progression of the predominant pollinating species at any given time, as long as it is a species that you want to thrive on the vineyard floor. It is important to allow the pollinating species to set a hard seed thereby allowing them to complete a full life cycle. Pollen is quite important in maintaining beneficial insect habitat.”  Committing to a cover, however, did not come without some hesitation: “Ideally the under-vine cover crop should not consist of tall weeds that will inhabit the fruit zone of the vine. As the mowing becomes a standard practice in a given vineyard this concern basically disappears due to the fact that tall weeds can never set a hard seed. They are mowed before the seed head forms. With that said I tolerate some tall dry grasses that have gone to seed and late season flowering weeds that reach the fruit zone.”

Within the lens of biodynamic philosophy, Barbara elected to allow for natural cover to initiate under the vine rather than seeding: “Every plant has an earth, water, air and fire zone. The earth zone is the root, water is the leaf, air is the flower, and fire is the fruit or seed. The earth and water are cool/watery elements and the air and fire are hot/dry. So when you think about this, you don't want a watery element in the fruit zone such as green grasses or broadleaves, we all know a watery element in the fruit zone is trouble. However a hot/dry element is probably fine. Late season dry grass seed heads or aster and goldenrod flowers have never proven to be a problem. This way of conceiving of plants by elements is a Biodynamic practice and has helped me make important decisions about our under-trellis biomass.” Barbara decided that the most sensible option for under-vine cover was natural vegetation: “I believe opportunistic plants grow where they are needed so we have allowed natural cover to come in. We have about 20 grass species and over 40 broadleaf species on the vineyard floor.  As the meadow evolves new plant species appear every year signaling a more complex ecosystem. I have inter-seeded clover twice in 13 years down the row middles in order to fix more nitrogen in the soil.  Since shifting away from herbicides in 2004, she notes that the observed results have been favorable: “Quite frankly the entire vineyard has gone through a paradigm change and me along with it. To give a simple list in regards to the vineyard ecology: excess rain water uptake by shallow rooted opportunistic weeds, better soil tilth, increase in soil microorganisms and soil animals, lower requirement for outside soil amendments, beneficial insect population, less frequent hedging, a happier vineyard crew and a general sense of peace in the vineyard.  In regards to the fruit and wine: earlier ripening, higher Brix, better native yeast population on the berries, and more balanced wines.” 

Having been very pleased with her results since initiating and maintaining an under-vine cover, Barbara is optimistic about the potential sustainable progression of under-vine covers. “If the East Coast can eliminate or at least greatly reduce herbicide dependence in vineyards, and I believe we can do this on a large scale, East Coast vineyards will constitute some of the healthiest farm soils in America. We are farming a permanent crop and a woody species at that; we don't require yearly tilling which destroys soil structure and the vines will out-compete weeds as long as the vineyard floor is maintained. Allowing the vineyard soil to regulate its natural cycles autonomously will bring about ecological balance that is hard to match by human hands. The theory of entropy is that eventually all order will turn to chaos but with natural cycles the fact is that all chaos will turn to order.”

Interview by Matt Gura, CCE-SC intern.

Matt and our other summer intern Drew harvesting cow horns for Barbara's biodynamic preparations.

What can I say besides boy is it hot! After no rain in May, plenty of rain in June and now over a week in the 90's everyone is steaming in the vineyard. The plants don't mind because most vineyards have irrigation or are old vines with extensive root systems. Actually, the heat will do the vines some good after such a cool spring. It is hard to stay motivated out there. Even the cover crops are starting to take a hit. Here are a few shots of clover under the trellis down at Channing Daughters Winery. These photos were taken on July 12th just before we moved into our second week of a heat wave.

The clover seems to be holding up well. This is the second season at this site and it came back nicely this year. Weeds are not as much of a problem in this trial but there is some mugwort that may be hard to control since it isn't being mowed.

Our summer intern, Matt Gura, will be posting a series of interviews he is conducting with the growers that are participating in the under trellis cover crop study. Here is his first interview with Jim Thompson, vineyard manager at Martha Clara Vineyards.

Greetings!

I recently had the pleasure of meeting with Jim Thompson to discuss his experiences with under-vine cover crops.  Jim manages Martha Clara Vineyards, where the CCE-SC grape program has the replicated trial evaluating under trellis cover crops.

Prompted by observing practices in the western US and Europe, Jim has been interested in alley and under-vine cover crops for many years.  The exposure led him to critically reflect on the impact of conventional practices involving herbicide use: “As it became more obvious that herbicides were going to become an issue for growers, like leaching, disruption of the dynamics of the ecosystem on the vineyard floor…and it became more popular to think about these issues, I felt that [covercrops] just made sense.”

When Jim was confident that the vines where he observed various cover cropping techniques did thrive, he recognized the relevance such strategies could have in his own vineyard:  “[My] vines are crazy vigorous, and in a region where some years you can get 10 inches of rain in June, what better way to soak up some of that water than these cover crops.”

                Jim has experimented with wall to wall cover crops in years past, but he primarily maintains an herbicide strip under the vine.  As he continuously follows under-vine cover crop research, I asked him if he considered the results positive such that he may be ready to adopt the practice: “Encouraging, but not positive.  We haven’t hit it yet as far as I’m concerned.”  As to what particularly concerns him, Jim replied: “Simply the management of them.  As they get too tall and get too close to the bottom of the vines, an issue is moisture retained by those groundcovers that transpires into the canopy.  If the soil is bare, then that would never happen.  There’s more to think about.”

Interview by Matt Gura, CCE-SC intern

                                    No mow only treatment at Martha Clara on July 9th.

We spent yesterday with Cornell University Professor Justine Vanden Heuvel touring our under trellis cover projects. She has similar projects going on in the Finger Lakes but is focusing her research on annual cover crops as opposed to perennial ones like we have in our trials. She brought her two grad students that are working on these projects. Here is a photo of the whole group over at Old Field.

We also stopped at Martha Clara, Mattebella and One Woman to see how the various trials are progressing. It is always nice to get different perspectives and share ideas on topics that are new and constantly evolving. One of the things we discussed was even though they are seeing differences in nitrogen levels from petiole samples there are not significant difference in vine growth between treatments or fruit parameters at harvest. This may be because they are not using a permanent cover crop year round like we are. They need to hill up their vines to protect the graft union in the event of an extremely cold winter. They are tilling in their cover crop each fall which may be providing a boost of nitrogen. Will be interesting to see how their trials progress compared to ours. We'll keep you posted! 

The season is well under way and the project is keeping us busy. At the beginning of June two interns from Cornell University came down to help in our research vineyard as well as with the maintenance and data taking in the under trellising cover project. Matt Gura and Drew Harner will be helping us through August.

We added three more under trellis sites this summer. One at Palmer, Old Field and Duck Walk Vineyards. Palmer and Duck Walk seeded clover under the trellis and Old Field seeded a low growing fescue mix. We will also be adding a fourth site in the fall at Shinn Estate. We want to see how germination rate and establishment are influenced by a fall seeding. The thought is that establishment of ground covers will be better in the fall when it is cooler, weeds are not actively growing and there is typically more rainfall.

Duck Walk clover just germinating in the Chardonnay on the left and Palmer clover in Syrah on the right.

Quick shot prepping the site for seeding at Old Field. The grass has since germinated so I will have photos up soon of that. 

 

We also have several sites that have since expanded their plantings of under trellis cover this year so I will describe some of those situations in future blog posts.  

Lets talk lysimeters.

When developing this project we came across some research done by Cornell University Professor Dr. Ian Merwin and Dr. Warren Stiles and their work with groundcovers in orchards (Merwin and Stiles, Orchard Groundcover Management Impacts on Apple Tree Growth and Yield, and Nutrient Availability and Uptake J. Amer. Soc. Hort. Sci. 119:209-215 1994). They compared various conventional and alternative groundcover management systems including a "living mulch" of crown vetch, mowed sod, chemically growth regulated sod, preemergence herbicide, postemergence herbicide, hay-straw mulch and rototilling. What we are interested in from this study is in the mowed and growth regulated sod treatments extractable soil N was reduced compared to the other treatments. We want to see if this is replicated in our vineyard trials but we also want to see if our seeded clover is fixing and releasing a measurable amount of nitrogen (the timing of it and if it is being taken up by the vines, through petiole analysis). To do this we have installed lysimeters.

With the help of the CCE-SC Agricultural Stewardship technicians we installed 39 lysimeters (for each treatment and rep) in the vine row at both the LIHREC mowing trial and the seeded cover trial at Martha Clara. Lysimeters are a large volume sampler designed to be installed near the ground's surface. We purchased 48" length lysimeters, put them in approximately 42" in the ground and will collect groundwater samples that we can analyze for nitrogen.

We will extract water samples throughout the growing season in the hopes of getting a handle on how our treatments are impacting N movement through the soil.

Innovative Under Trellis Management in Wine Grapes

2012 Summary by Alice Wise

In the spring of 2012 the CCE-SC grape research program received a multi-year grant from the Northeastern Sustainable Agriculture Research and Education program (SARE). This project is designed to explore the use of cover crops or mowing for management of the area under grapevines. The majority of eastern winegrape growers maintain this area with herbicides, considered to be the easiest and most cost effective strategy. Green growth under vines is often viewed as detrimental, competing with vines for water and nutrients. However, many growers endeavor to reduce pesticide use and are therefore seeking viable alternatives. Forty-six growers in eight states responded to a survey conducted last spring to document current practices and gauge interest. A webcast broadcast to fifty participants highlighted related work of two researchers and reiterated the benefits of cover crop strategies.

The first objective of the project is to document that more growers are adopting mowing and/or green covers under the trellis. This is an effort to reduce leachable nitrates, reduce or eliminate herbicides, and reduce canopy management inputs, saving vineyards money while maintaining or improving yield and quality. In 2012, five growers agreed to seed cover crops in their vineyards seeding a total of 17.25 acres. These plots included several types of clover and no mow fescue mix. In several cases, the expense of seed dictated the choice of cover. In one vineyard, clover plots did not germinate. Some growers were unwilling to host herbicide plots for comparison, understandable for those with a goal of avoiding herbicide use.

In three of four vineyards, there were visual differences in vine size and leaf color between groundcover treatments. In one vineyard, vines were noticeably larger in clover plots. In a second vineyard, vines with clover seeded in 2011 were much larger than vines with clover seeded in 2012. Fruit in these clover plots had lower sugar and higher acids at harvest, suggesting a delay in ripening. We have not yet taken pruning weights in the third vineyard. While the vine size difference was not surprising, we did not see this same result in our cover crop research study. Similarly, we have not found any differences in fruit ripening among treatments in our replicated cover crop study.

The second objective is to determine the impact of undervine mowing on vines. This trial involves four treatments: T.1 - season long mowing (5 times); T.2 - glyphosate only (3x); T.3- mowing (3x plus glyphosate early July); and T.4 - mowing (4x) plus glyphosate early August. It is located in a Merlot block at the LIHREC research vineyard in Riverhead, NY. There were no significant differences in shoot length (measured three times) or shoot diameter. Vine pruning weights have yet to be analyzed. Vine nutrition, as determined through the analysis of leaf petioles, was similar for all treatments with the exception of phosphorus, which was lower in the glyphosate only plots. There were no differences in yield or fruit ripeness at harvest. We were hoping that the use of green cover (potential competition for water and nutrients) would reduce berry size (higher skin:flesh is desirable in reds for color and flavor compounds) but we have not been able to document this effect. Lysimeters to gauge nitrate leaching will be installed in the spring of 2013.

The third and final objective of this project is to evaluate the impact of seeded under vine cover crops. This trial involves four treatments: glyphosate only (2x); Dutch white clover; no mow fescue mix; and a combination of clover and no mow. This trial is located in a Syrah block in a commercial vineyard on Long Island. There were no significant differences in shoot length or in shoot diameter. The six central vines in each plot were pruned on December 6. Vines in no mow plots were visually smaller though not statistically significant (p=0.0522). There may be differences next season if this trend continues. Pruning weights in the clover and herbicide plots were similar, unlike what was noted in several grower vineyards. In petiole analysis, though not statistically significant, there was a trend for lower petiole nitrogen in no mow plots. The two treatments with clover had significantly lower phosphorous levels. Phosphorous fertilization is often recommended when establishing clover for forage. Long Island soils however tend to be high in phosphorous due to a history of row crop vegetables prior to vineyard establishment. Lysimeters to gauge nitrate leaching will also be installed in this experiment in spring 2013.

I have been on sort of a blog hiatus this winter. Not for any reason other than it has been a busy winter analyzing data. We have some information from our first season with this project. Go to our webpage at  http://ccesuffolk.org/grape-research/ and click on the report titled "Innovative Under Vine Management Strategies" to see the full report. I will post a somewhat abbreviated version on this blog.

We spent some time looking at pruning weights this winter to gauge impact of covers on vine growth. Here is a before and after shot of one of the Merlot vines pruned in the research vineyard.

We will have a little more help this summer with the addition of two full time Cornell students as well as a part time person. We also have four additional vineyards that have joined our original five to try out groundcovers in their vineyards. More to come on the new blocks as well as a few interviews with some of the growers who participated last year and their thoughts on the first year of this work.