Strategic Farming: Field Notes

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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.