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Farm Viability Cover Crop Trial

I’m Luke Haggerty I’m the viticulturalist at the Lake Erie Regional Grape Program which is part of Cornell University. We received a grant from the New York farm Viability Institute to look at cover crops and
concord vineyards. My name’s Kevin Martin. We’re pretty excited here today to talk
about some cover crop work that he’s been doing the last couple of years. I
think it’s pretty new for perennial crops and grapes so hopefully we see
some changes in the industry because of it. So we did a two-year cover crop study
where we teamed up with the area grape growers and looked at what they’re
planting. We tried a few different mixes. We had a few of the growers trying up to
8 different species in a single cover crop mix. And another grower that tried
like 8 different series of mixes. So it was a good time to kind of get out and
take a look at what was going on. And then we evaluated pruning weight, soil
I guess soil structure, and soil nutrients and things like that. Also vine
health, things with the petiole. But we also looked at weeds and how which cover crops are
suppressing weeds and yield. And just kind of did a whole shotgun approach to
try to figure out as much as we could in that two-year time period. We got a lot
of exciting data when it comes to vine size in our pruning weights and a lot
of our weed data. I know a little bit about cover crops and it seems like you
can do a lot of different things. And the choices of seed mixes can be very
complicated. But in a period of two years, what was the biggest takeaway? Was there
anything that happened that was dramatic? I think the the biggest takeaway I guess
my number one recommendation would be annual rye grass and tillable radish mix.
Those just those two mixes are pretty common. But those two mixes with a clover added in there to help build your nitrogen base was also a positive thing.
But when we looked at the data a lot of positive things happen when you had
annual rye grass and tillable radish. And for rates for that, the rate of annual
rye grass was around 15 pounds an acre and the radish was about a pound an acre. When we planted more than a pound an
acre we started to kind of shadow out a lot of that right grass that we planted.
So we lost some of the benefits there. So around a pound of radish seemed to be
sufficient. Was there an impact on vine size? In a good way and a bad way. So
really at this project really show that there’s a
lot of potential here but there’s also some risk here. So knowing what you’re
planting and more or less when to terminate is important. And what I mean
is we looked at gravelly sites, heavy clay, and loamy soils. And all those sites
where we had classified with NDVI like where smaller vines were at and medium
vines. So kind of on the lower end of the producing scale. Where they had cover
crops the vine size jumped dramatically. Which is great I mean we’ve been trying
to figure out how to get our small vines bigger for a long time. And in two years
we’re able to increase anywhere from 10% or 15% all the way up to
30% of those small vines in size in just a short amount of time.
Which is great. However, the bigger vines I think some of the competition that’s
involved with planting the cover crop those bigger vines they saw in some
cases especially on the gravel and loamy sites were where you had big vines the
cover crop competed with them and you can see a dip where they actually
decreased in vine size. When you looked at everything together there was still
an overall increase in overall vine size. But that came from the small vines and
big vines are such a dramatic uptick from those and a small you know down
down tick from the other thing. And I think really that has to do with when
we’re terminating. So growing cover crops in concord grapes, we really have the
sky’s the limit for planting. We can plant at any time. We can terminate at any
time. So we have a large window. And I think we kind of found through the study
that really looking at when terminate or kill the cover crop is very important.
Yeah I mean my big takeaway from looking at what you’ve presented is really being
careful about termination on gravel soils. And I think maybe those effects
were exaggerated because to provide some context were it’s very early 2017 now. So
this happened in 2016 and we had a very severe drought in 2016 of really
historic proportions in our area. So maybe that effect was exaggerated. But
regardless it’s going to be severe and it’s a risk that I think growers should
probably avoid even though that drought was so dramatic. Any kind of water stress
is going to cost a lot of money. To me it seems like the big takeaway is rye grass and radish worked very well for vine size and for weed suppression. Where we had radish and annual rye grass
we had the best weed suppression especially when we were looking at
marestail. Marestail has been a big problem for grape growers to kind of control
across the belt. And that combination really seemed to suppress I mean almost
fully suppressed. It didn’t show up in our weed counts but when you’d stand back
and look at it really would see a couple here and there. And then where he didn’t
have cover crop or a different cover crop mix was planted where he didn’t
have that combination you saw marestail in there. So that was a big for weed
suppression that combination worked very well. So I think I think we have a really
nice introductory combination for some immediate impact. Which actually
surprised me. And the only other major takeaway is just termination and being
careful with termination because it can result in some negative effects as well.
My recommendation right now is that if you’re growing on a gravel site or you
have large vines, so we don’t have that competition with the cover crop, that the
cover crop should be terminated when the shoot length is around six inches. So I
would say that 3-6 inch stage depending on how the weather outlook
looks, I would be gearing up to terminate around that time. In the past we’ve been
going more that later May. Where the shoot lengths probably 8-10 are
almost bloomed. I think waiting that long is where we’ve seen that impact of that
competition. So being able to eliminate and I think as a six-inch stage shoot
our cover crop is we’re still getting a lot of growth out of the
rye grasses. You know almost knee-high and a lot of the clover is really going
at that time. So I still think we’re getting a big bang for our buck at that
time. And anything past that might just be a little too risky to go with. On the
heavy ground you could probably delay that to later May or 8-10 because we
found that that didn’t have the impact even on the dry year on the heavier clay
soils. That you could have you had more leeway and let the longer you let them
go. We still saw an increase in production. I just want to highlight that
because I think that’s new viticulture for a lot of our growers. Ever since Bob
Poole really, row middle termination advisement has been at
bloom. And you’re pushing it back much closer to bud break around six inches of
shoot growth. So that’s very different and that’s not doesn’t just apply to
cover crops. But it is kind of a different direction than many of our
growers have heard in the past. I just want to remind growers that is new
information. Talking to Kevin about some of the economics behind cover crop data
that we’ve gathered over the past two years. Now as part of the project that
looking at cover crops we looked at yield and we looked at vine size and
that correlation with cover crops. And we started to find some pretty interesting
things. So Kevin’s been taking a look at that, Kevin do you want to kind of maybe
start a little bit about what we’re finding. Absolutely. So when we first
started looking at this project the one thing we were really focused on were
seed costs and application costs. And trying to justify why a grower would do
cover crop as many growers in our area don’t utilize cover crop for their row
middle management. And I think we can talk a little bit more about that. It is
kind of a complicated question because there are so many seed mixes. But really
I think the focus is just on having cover crops versus not having cover
crops. Because what we found is some pretty dramatic effects and those
effects happen with some relatively inexpensive seed mixes sort of shifting
our focus away from what seed costs and towards how we manage cover crops. So for example we saw a relatively dramatic increase in some of the heavy clay sites
when we use cover crops versus not using cover crops. And what that really
translates to from an economic perspective is at least a $225 increase in gross revenue per acre. That investment was
around $40-$50 per acre to get that $225 increase. We want to look at this for a few more years if we can to see if
that $225 increase is a one time increase or if
it’s more of a permanent benefit as a result of increasing the soil health. We
know at least though that we saw that increase in the sort of in between the
third and fourth year of cover crops on that heavy clay soil. So that was really
impressive and probably more dramatic than what I expected. And just to kind of get in a little more of the background on there the heavy
clay we saw where there wasn’t cover crop we had half pound vines and where
there was cover crop we were almost a pound and a quarter. However when we move to the gravelly sites I think we saw there is a little more risk there. Where
we had cover crop especially big vines and cover crops that where we had cover
crops on big vines on gravel sites we saw a decrease in vine size. So there is
risk there and maybe you can talk about some of the risks with cover crops and
how we can navigate around them. In some way I think we can almost talk
about one of our failures in terms of cover crop management. And I think that’s
the point of research is we try to figure out what works and what doesn’t
work. And a late termination or no termination on gravel in a dry year has
some really dramatic effects. And to some of our growers that may be stating the
obvious but those effects were actually very dramatic. So we’re looking at a two
and a half pound vine nearly on a gravel site in terms of what our average was.
And we were reducing that to a one pound vine. So we’re going from a relatively
healthy decent performing vineyard to something that’s really struggling and
needs rehab in the course of a single year. So we’re looking at a decrease in
yield of about $200 per acre related to that water stress. And
most of that presented itself in berry size. And in addition to that, since it
did present itself in berry size that stress was already there. So you’re
looking at probably at least another $350 in potential crop loss. Depends on those sites. So I think looking at an earlier
termination is really a key a really important thing to kind of look at going
to the future. Yeah I really think that there’s a potential for gravel sites to
benefit as much as heavy clay or more. We think of a gravel site as better for
vineyards. And for the most part it often is, but the benefits that cover crops
offer may disproportionately benefit those gravel sites but only if you
manage it correctly. And it looks to be a lot more finicky so just be careful with
your termination dates. Yes. And how they they bump up their vine
size instead of decreasing it because that’s really where the rubber meets the
road when it comes to economics. So from this research project I think we were
able to develop quite a few recommendations on the do’s
and don’ts of planting cover crops in concord vineyards. With that I’d like
to thank the New York farm viability Institute for funding this work. And I’d
like to thank the participating grape growers that were involved, they’re
the really driving force of this project.

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