I'm Ryan Miller, crop
extension Educator earlier this morning.
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Again, welcome again to
today's Strategic Farming Field Notes program.
Happy you joined us today.
My name is List. I'm an extension educator in crops.
I work out of the Worthington Regional Extension Office
and we welcome Dr. Devlin Sarang. Here's our extension.
We managed specialists with
UM Extension and also Dr. Joe Eks extension.
We managed specialists with
North Dakota State University.
We also thank our sponsors, Um extension,
and generous support from
the Minnesota Soban Research and Promotion Council
and the Minnesota Corn Research and Promotion Council.
With that, just a little crop
update that actually came out
yesterday due to the memorial weekend holiday.
Corn's pretty much mostly planted here in Minnesota.
93% planted soybeans, 86% planted.
I know that varies across the state.
We've had some excessive moisture areas,
we've also had some dry conditions in some areas.
We've got some replanting,
a mix of all different things,
but we wanted to focus
today looking at cover crop research and then
also how that ties in
with weed management and any issues there.
First of all, I just want to start with and
see Devlin and Joe.
If you guys could just describe some of
the cover crop research that you've been doing.
I know you've been working with that from
the angle also of helping us with what control?
Especially since we do have
so many issues with herbicide resistant weeds.
Joe, why don't we start with you first.
If you just want to take
a few minutes just to describe some of
the cover crop research that you've
been working with and give
us a little background on that.
Yeah.
For the most part we've really been looking at
using rye course planted in
the fall and then terminated at different times in
the spring primarily for control of water.
Mp has been the goal of our research
that's just continuing to be a worse weed every year,
it seems, and we get new resistance that pops up as well.
And knowing that
the herbicide options are pretty limited,
seeing what else we can do to help out rye is one of
those easier to adopt
management practices on a large scale.
And so the last two years what we had
done is looked at different termination timings.
So either we'll just say
no cover crop or the absence of rye completely or
terminated 14 days before planting or planting green.
And in that case, we planted and then terminated
rye either the same day or the next day,
but after planting was the important thing there.
Then we couple that with
the presence or absence of a pre emergence herbicide.
We just happened to choose
fierce common pre mix of a group 14, group 15.
And then what we did was within
each individual management factors,
so rye management and then absence or presence of a pre.
We waited until water Mp was
4 " tall in those plots and then triggered
a post emergency application and then
saw how the overall control
worked at the end of the year.
And the short answer for water him
control is when we had
rye and a pre emergency herbicide in the mix.
Those two things worked pretty well together.
But when we did not have
the rye or we did not have a Pre,
when we started to lose control,
certainly by the end of the year.
And so look at
those two things as complementing each other,
but certainly some folks look towards hope of pay.
Can rye replace a pre emergency herbicide?
And we have not seen that in our research.
Interesting.
That's good. But you're seeing
a contribution at least with the water hamp.
Even though water hamp is one of
those later emerging weeds too.
Yes. Yeah. Probably also
have to keep in mind that everything
happens pretty quick here.
Once we get green up of rye.
It's usually here in Fargo
about the last week of April, 1 week of May.
And then we have waterhemp
emerging about two or three weeks after that.
A much shorter window up here,
which maybe helps out with water management,
compared to maybe where Devlin's
at or where you guys
are at a little bit further south where that
right greens up starts accumulating biomass a little bit
earlier and maybe have
a month head start compared to just a couple of weeks.
Yeah. Yeah. Devlin that ties in.
And Joe, we'll get back to some
more of your work too of course.
But Devlin, if you want to just describe some
of the work that you've been doing
across the state as well.
Yeah, what Joe is doing up in North Dakota
that reflects our situation
in the northern part of Minnesota,
North Dakota or Red River Valley.
Whereas most of our cover crop research is down south.
And we do in the eastern western side of the state,
but in the southern part of Minnesota, as Joe mentioned.
Actually, we're also looking at the serial right,
like false serial right,
as a potential cover crop candidates for Minnesota.
And the whole game is the biomass.
Because if you have enough biomass,
you'll get enough benefits
from the standpoint of weed control,
from the standpoint of
soil erosion control and everything.
It's all about the biomass.
How much biomass you can
get out of this cover crop in the spring.
If you see the reports by USDA back in
2017 when they did the last cover crops survey,
Minnesota was one of
the bottom states regarding the adoption of cover crops.
We had only 4% corn and seven acreage under cover crop,
whereas in the nationwide the increase
2012-2017 was 50% increase and state like Maryland,
Pennsylvania, they had like 22,
35% area under cover crop.
And then if I compare
our Minnesota situation with
like other state as I mentioned,
like Maryland, Pennsylvania, the reason is
like we have a unique environmental conditions.
So as Joes, we have
really small planting window
between the harvest and the first frost in the fall,
and also we have unpredictable weather.
E.g. last fall was so dry in Minnesota and North Dakota,
I know that there was barely
some emergence of cereal rye that was planted last fall.
But again, in the spring after snow melts,
we have just a couple of weeks
before we plant our corn and soybean.
This is the main challenges
for adoption of cover crop in Minnesota.
We are looking at different management practices,
how we can, uh,
adapt the cereal rich cover crop based in Minnesota.
Our research components definitely
focusing on weed management,
but our treatments or the comparisons we are
making are like different cropping systems like corn,
corn system versus corn,
soybean system, including silage corn, if that helps.
And also we have different seeding rate for cereal rice.
We wanted to see, okay,
if we increase the seeding rate,
maybe 1.5 times,
or two times the recommended seeding rate,
whether we can gain the biomass quickly.
But we found that was not the case.
Like if you have
60 pound per acre cereal is seeding rate.
I think that's optimum
which is also recommended by the sale.
And then we're also looking at
different termination timing in the spring.
So if you delay your cover crop termination by a week,
maybe by two weeks,
maybe by four weeks,
how much biomass you can accumulate,
whether that helps with the wheat control.
And so that we have different termination timing,
different planting dates.
And we're like juggling with a lot of factors.
And we're trying to find out what are
the best recipe for cover crops in Minnesota.
And we started this research in 2020.
1.20 22 was our first year when we get the data.
And what we found is 2022 was a good year for cover crop
because 2021 fall was not as much dry as 2022 fall.
This year will be the second year for
our research and we'll look into that,
like how much biomass we can
get this year out of these studies.
Basically, we'll have two years of
data to summarize by the end of this season.
Very interesting. And that's one thing you
bring up the biomass question too.
Just curious because I've seen
the research where they're talking about you need
to have like 4,000 8,000 pounds of
biomass per acre to actually
have an impact on weed management.
What have you found and what kind
of levels are you reaching?
Dublin. And then I'm going to send
it over to you Joe too.
For the further northern parts of the state here area.
Yeah. If I look into last year's data, I mean,
when you planted early last year also our spring was
wet 0 early planting was not really early. It was like.
I would say like it was like tenth of
May when we planted our soybean and corn.
And that time we got about
1,000 pounds per acre type thing.
It was not that much like as you
said like 4,000 No, we didn't get it.
But still we saw with 1,000 pounds per acre,
like we got like some
weed control benefits earlier in the season.
And then when we planted late,
which was end of May,
we got about 4,000 pounds per acre and which
was really desirable because
those plots was pretty clean.
But, you know, sometimes if you wait until end of May,
you may get yield penalty from your cash crop.
That is the whole thing we're studying like, okay,
what is the biomass we're getting and
how much benefit we're getting from that much biomass?
That's why we have
different planting dates, different termination timing.
And as I said,
whatever the biomass you get,
that might be helpful.
But if you get really little biomass,
like this year happened,
like I told you, last fall,
there was not much emergence.
And this year in the spring with the early planning,
we didn't get much biomass.
We'll see how much weed control we can
get out of that, Joe.
Yeah.
How about, how about you, Joe?
Because again, biomass, that
seems a really driving factor,
what we're getting from a weed control contribution
and other potential soil benefits too.
But what amounts are you seeing
and the impacts of
practices on how much biomass is produce?
Yeah, I was just looking this up here.
It looks like about three to 4,000 pounds per acre,
is what we've been getting here in
the Fargo area for our research
over the past couple of years.
That leads into, like I said,
it's not standalone great practice
or replacement of a pre emergency herbicide,
but that's about half of what you're quoting there that
some other states really feel comfortable with getting.
As far as biomass production for
complete wheat suppression makes sense.
It's about a 50% control measured in that case if
we're producing about half the biomass
of some of those other studies.
Now, this year is a little bit different,
certainly North Dakota and Northwestern Minnesota.
A lot of the talk this year has been
that we planted rye and winter wheat for that matter,
into dry dirt, and just never got emergence last fall.
And then finally, when the snow melted,
we got emergence this spring.
And it's a question
of did we get the vertilization requirements?
We actually bolt and try to produce seed.
And here at least in Fargo,
it seems like we did achieve that.
But we're not going to get much for biomass.
And there's certainly a carpet of
water hemp in the research trial that I'm staring
at this year will
definitely be one of those years where we're not
going to get a lot of biomass production.
The overwintering benefits that other
folks like for ancora soil
and preventing blowing. That didn't happen.
But we're still going to see what benefit we'll
get because we're shifting into
a new phase of our cover crop research.
We are trying to delay
termination as late as possible after soybean planting
primarily for weed control but also for
potential yield loss from rye due to soil usage.
That's always one thing that we will run into
is the fact that moisture is very
important and we'll get
these dry stretches and we're in one right now.
A lot of people are too
where we don't want that ride to use up too much water.
We're going to go all the way to V
three soybean this year,
waiting to delay termination until
V three soybean and see when the sweet spot is for
getting weed control without having that
rye use up too much moisture
to take away from soybean yield at the end of the year.
This year might be a little
confounded by the low biomass.
The fact that the rye didn't come
up until about a month ago,
but it will be repeated in
future years and hopefully get back to that
4,000 pounds or so biomass and see what the results are.
And then more typical setting
than the dry fall without emergence.
Yeah, a lot of factors, as you all know,
play a role in how much biomass you get out there.
And what the take is interesting,
it sounds like you're looking at looking at
the V stage of soybeans for when you terminate the cover.
Crap. What aspects have you looked
at Dublin so far too
as far as one to terminate the cover crop?
Because again, there's a lot of
different triggers that you could
use as to one to do the course.
Also going to look at the potential
yield impact on our cash crop too.
Yeah, for the termination,
definitely, As I mentioned,
our main target is the biomass.
Then we also looked at different termination option,
like what are the termination option
you can have for terminating cover crop?
Because we know that chemical termination options
are the best because it works fast, it's economic, but.
We saw that different chemical group,
they work differently. E.g.
it is well known that round up spraying,
round up is the best option
for terminating cereal, right? Cover crop.
It really works fast.
In that case, within ten days we have a field this year.
Within ten days, everything is yellow and brown
and you're ready to plant
even some options like Cleo edam.
They're slow. We select
max type product, they're really slow,
and it takes three weeks to get it yellow and
it's not totally yellow, it's really slow.
We have options when you have like glyphosate type,
like Liberty type product,
it is not 100% kill.
We have to pick those herbicide options carefully.
And also we checked some termination option for
the organic grower because we
thought like some of our organic growers,
they're interested to use the cereal rye cover.
If they have the roller crimper,
that is good idea because they can
roller cereal rye and can start planting something.
But we know from
the literature that roller crimper is not also
100% kill for the cover crop
and it's also stage specific.
We tested some of the non herbicide options
for the termination of
cover crop and different stage of the cereal rye.
And we found that if you were like cutting
the cover crop for any kind
of like feed purpose
or you're doing gradging or something.
Doing it early in the tailoring stage
is not useful because you'll
get about ten to 20% control
and those cover crop will come back.
However, if you wait until the heading stage,
which is probably not desirable for feed
because that time it's like more hards stem but
you'll get about 50% kill of those cover crop with
the telageaw similar thing but if you do
like light telge rototill
just to mix up those biomass with the soil.
Though, in cover crops situation,
our goal is not to disturb the soil because
we promote not disturbing the soil.
But sometimes for the organic row,
you have to terminate the cover crops.
If you do light teelge,
rototill, mix up those cover crop biomass
in the top layer of the soil.
You have to wait until a later stage because that's
the time when you'll get
about 100% kill those cover crop.
However, if you do it early in the tillering stage,
you can get up to 75, 80% kill.
But there will be some cover crop or cereal rye that
will get established after the roto tail.
A lot of tradeoffs in this whole thing, isn't there?
Yeah. Joe, I want to get back to something that you
mentioned earlier too is your work with pre herbicides.
And I understand you've been doing some work
where they're looking at because the nin,
you've done some work too with pre emergency herbicides,
with that termination application of the cover crop.
And there's always a concern about
interception of the cover crop, the pre herbicide.
You're going to get as much activity
and so forth. What have you found, Joe?
If you want to just elaborate a little
bit if you can, what you've found so far.
The effectiveness of pre herbicides,
when you do have a cover crop out there,
they have an impact on efficacy
and how much is actually
actually reaching the soil and so forth.
Yeah. And the trial that I've
been doing that you're referring to as
part of a national effort,
I think 13 or 14 or so states
involved for those states took an additional step.
I was not part of that, but I do
know the results of the data.
But if we look at
just the weed control aspect
from using that pre emergence herbicide in rye,
I'd like to just phrase it as R
plus a pre herbicide is better than either,
either one of those alone.
If we don't have that rye cover crop and just rely on
a premergenc herbicide that
will start breaking after three or four weeks,
which is what we expect when there,
with a post emergency herbicide, we might buy an extra,
maybe 14 days before needing to apply a post herbicide.
If we have the combination of rye plus a pre,
compared to just the Pre alone.
Or just that rye alone.
I've taken a look at it of how many days are you buying
yourself until water hemp gets to 4 " tall.
And looks like, yeah,
about ten to 14 days on average when you have
that R plus the pre combination compared to either alone.
Now, the next step
that those four or so states have taken.
Is taking soil samples from
these plots and trying to
determine where the pre emergence herbicide actually is.
Because we're always concerned about interception of
that pre emergent herbicide with the cover crop.
And the short answer is yes,
the cover crop is intercepting
some of that pre emergent serbicide.
Forget the exact numbers,
let's just say somewhere in the range of
70 to 80% of the herbicide makes it to the soil surface.
So maybe that 20 to 30 was intercepted by
rye compared to a standard check with no rye.
And the same rate of a pre emergent supplied.
So based on the soil core analysis,
we're tying up 20 to 30%
And don't quote me exactly on those numbers,
don't have the data in front of me,
but we are tying up some of that residual in the rye.
But the end result from a weed control standpoint
is they are also seeing
similar observations like I have that you are
getting better control with the two practices combined.
So I know it's
never encouraging to have
some residual tied up in that case,
but the main point there is that
the overall weed control is better in
that system even though we are getting some tie residual.
Bottom line is it's helping out.
Right? That's one question too that's come up and we got
some of these questions at
registration to, for this program.
And sometimes people look at cover crops and for
we control. What do you think?
It's pretty challenging in
a conventional system to get
100% of your weak control from a cover crop?
We've got other tools that we can use.
How do you address that?
Double shoot that over to you first.
Just thinking about people
wondering whether or not the value that
a cover crop can provide from
a weak control standpoint in a conventional system.
Yeah.
I think with the herbicide resistance issues
that we are having in all of the Midwestern state,
we're struggling with Waterhemp
and Joe can talk about Sia.
We have some herbicide resistant weed issues in
our states and we
are talking about diversifying our system.
We cannot only rely on single herbicide to
mitigate these issues because you'll see
some Minnesota Crop News article
that is coming out tomorrow
that we'll talk about some of
the Waterhemp survey we did recently.
And it is showing that
multiple herbicide registered waterhemp
is prevalent in Minnesota.
It could be registered to two sides of action,
three sides of action,
45, up to six sides of action.
Those populations are still slow in
spreading that six sides of action resistant thing.
But in a couple of the years,
we'll see that registered treadmill is still ongoing and
most of our waterhemp
are showing resistance to multiple herbicides.
So that's why we need to diversify our systems in
terms of management practices,
rotation, herbicide options.
I agree with Joe.
We saw the same thing when
you combine this cover crop with a pre herbicide.
Probably you'll get the best benefits
out of this cover crop.
I mean, yes, the cover crop will
add some cost to your program,
but in the long run you'll get benefits out of it and
you'll get your soil seed bank
reduced in a couple of years.
If you diversify your system
that will help you in long run.
Any thoughts do you want to add to that, Joe too?
Because I know again you've had
some significant issues with Kosha and
just looking at multiple resistance
in that weed species too.
Yeah, that's another one,
just briefly on Kosha that we also can get
a benefit using rye for
Kosha control because of that early season biomass.
And that's not work that I'm doing but out in my
not Dr. Brian Jakes is playing around with rye.
And then combining rye with like
a fall application of flumixidenorvalorbiningwo.
Standard practices for Osha
control and seeing how that works,
a more north central part of the state.
But whether it's Kosha or water Hemp,
yeah, we're just getting
more and more herbicide resistance.
And anyone who teaches
herbicide physiology may disagree with this statement.
But the simplest way I think about
it is Ry is basically another site of
action that we can use if you want
to simplify it down to that level,
is that we need other solutions in
the long term for
control of those weeds like water, Mp and Osha.
The solution is not going to come from a jug.
Any new site of action is half a decade off.
At least I feel like we've been
saying that for the last half decade.
But we'll see how
long until we actually do get a new site of
action for major row crops
effective against weeds like water, him, percio.
If we look at just our solutions
we've been trying to achieve or
accomplish by getting
craftier with herbicide combinations.
I look towards the south
and Dr. Aaron Hagrid, University of Illinois,
I think has put it best when he starts talking
about the metabolic resistance that they have in water.
Him, we certainly have some of that
up here and some of our palm raman populations.
But when you look at metabolic resistance to herbicides
and the fact that it's almost
unpredictable which herbicides they will be resistant to.
The Illinois, they're starting to
reevaluate the standard practice
of tank mixing herbicides
as a good resistance management option.
There's some line of thought now that
with these metabolic resistant pigweed,
that tank mixing may actually increase the frequency of
how often resistance or
mechanisms occur or resistance
to new herbicide active ingredients occurs.
When we look at it simply
from trying to control using herbicides,
that I'm not going to put a date on it.
Those days are coming to an end at
some point in the future and
we need to integrate other tactics.
And that's why we're looking at easier
to adopt on the wide scale things like rye.
Now, harvest weed seed destructors
are now coming into the scene.
Some of these other tactics beyond
just a herbicide to really get
a handle on some of these really problematic weeds.
Most definitely. Diversification is key.
And I see we're just about out of time.
But any parting thoughts that you wanted to say here,
Devlin, as you wrap things up?
Early season weed control
here with cover crops or anything?
Yeah, this year I am skeptical how
much benefit we can get out of
cover crop because of the last dry fall.
And spring was also a late,
we got a lot of snow last winter.
It was late start for the rye in the spring.
But as we mentioned,
it's always good to start clean and
stay clean even if you're
adapting cereal rye as one of
the diversification key in your systems.
It is still good idea to have a Pre
on in case if you missed your Pre this year
because talked to a lot of farmers this year and they're
so busy and they're in a hurry to plant their crops.
Some of them missed their pres and I talked to them.
But I highly recommend them to come back
with a post emergence as soon as
possible or as soon as they see the weeds.
And weeds are like less than 3 " tall, like tank mixing.
Those post emergence with certain some type of
residual herbicides will definitely
help with the water control.
But yeah, that'll be my last thought for this spring
because we have a little bit different year
this year compared to last year now.
Thanks Lin. And how about you Joe?
Any parting thoughts here as we wrap things up?
Yes. I'm just going to take, not a 180,
maybe a 90 degree turn here and focus just on how
warm it has been this spring
with regards to premergent
herbicides because we've been warm,
dry in the last week up here, we've been very windy.
And just a reminder for folks that
many premergent herbicides cannot
be used once crops are starting to emerge,
we focus on soybeans,
things like Fumi Oxygen or
Valor Soft Ventrone or the Spartan Authority products.
Once the soybeans are emerging,
we can't use those products due to a high risk of injury.
We've had a situation up here where
we've planted and just had
30 mile per hour winds and not been able to
get a Pre on before the beans come up.
I know we still have maybe 30 or
40% of our soybean acres to go in.
I'm assuming it's similar on
the other side of the river up this far north.
Just a reminder, if you're going to
get that pre on and we're challenged by
weather just to make sure that
the crop is not emerging because
it's happening pretty quick here,
certainly within five days of planting for soybeans,
which is a lot quicker than we're used to.
Excellent points. I should note that in the chat,
there's a link to Google Doc that has a lot of links.
If you have any links to add to that,
Joe too, we'll certainly throw those in there.
But again, to the cover crop website,
more information on planting green as well too,
because we just pretty much talked about weed management.
We didn't talk about all the
other potential tradeoffs and
challenges you might have from like
an insect of things too.
And the need to be scouting for
things armyworm and things like that too.
But anyway, I encourage people to check that out.
But again, I better wrap things up here.
Again, I'd like to thank everybody for attending
today and especially our speakers, Dr.
Sang Dr. and of course our sponsors as well to
the Minnesota Slaving Research and Promotion Council
and the Minnesota Corn Research and Promotion Council.
As you sign off today, again,
there's going to be a really quick survey.
I hope you'll take that. Also ask for input,
what we should talk about in future sessions,
things that are concerning you.
Next week we will have Dr. Sharma
and Dr. Fernandez on moisture issues,
looking at two dry and two wet and
supplemental nitrogen issues again.
Thanks everyone and have
a great rest of the day and hope to see you next week.