Hi I'm Daniel Smith, southwest regional agronomist for the University
Wisconsin and UW Extension Nutrient Pest Management Program and today I'm going
to talk to you about interseeding cover crops so look at interseeding cover crops.
You can accomplish this task by several different methods. One would be to broadcast
seed. So in these photos you can see a broadcast spreader on the back of a
tractor. You can pick these up for under a thousand dollars sometimes even under
five hundred dollars. And they do a nice job of broadcast seed and fertilizer and
crops and lime across the landscape, and they can be a good tool to have in the
toolbox for certain cover crop applications. And you can see in this
photo these were broadcasted oats into seed corn a nice heavy residue of
residue there that we could easily no-till plant into. We think about
interseeding, we often get questions like: Well, can I enter seed into soybeans? And
the answer is No. We have not been able to make interseeding work into soybeans.
We're talking about interseeding, when we plant a cover crop during the
vegetative growth stages of a crop. For corn (and soybeans) this is typically
between v3 and and v5, into v8 for corn. Then of course there's just too much
canopy pressure, from even 30 inch rows- in soybeans. Too much shade pressure to
allow this cover crop to stand the canopy pressure. These photos show those
mixed results. We have the innerseeders set up here for soybeans we see that we
got the radishes to germinate, however come harvest we only had radishes on the
field edges, in this particular case. We did have some winter rye that survived
that shade pressure, but a really poor stand of cover crops from that
competition. And again we'd suggest that this is a failure as well, so soybeans
interseeding are not likely going to work on your farm. We think about (corn) interseeding
though. And in most of research we've worked on the University of Wisconsin
has been with a modified no-till drill. So this is the drill that we have at the
Lancaster Agricultural Research Station that's been modified to allow the the
corn rows to go through the drill and not become damaged during using
that equipment. And this allows us to seed 3 rows of cover crops within
those 30 inch rows of corn. And that allows really good seed to soil contact.
It also allows for consistent seed metering for an accurate seeding rate. We
look at some of the challenges of using a no-till drill as topography so we look
at this photo of the Lancaster area culture research station and the
Driftless region we see the contours and in the rolling topography and a drill
may become a little bit more challenging to use in those landscapes I have used
with success a drill in those landscapes but it required some pre-planning and I
really considered some some forethought on how we're gonna set up that drill to
work in those scenarios we can see that our drill really closely fits in in the
rows anyways we're touching that outside row corn with the end wheel we also have
a three-point drill that we use for the application so we tighten up the
three-point linkages to prevent that drill from drifting down the hill this
is where the broadcast seeder is gonna have some advantages the broadcast
seeder is also going to have certain advantages when it comes to speed but
the drills tough to beat when it comes to good seed to sow contact and having a
really good stand in the fall we also want to think about mashing our
equipment size to our planter and this is really important in rolling
topography because we want to match that equipment so that we're planting four
rows of corn to a four row width piece of equipment for our cover crop
interceding twelve rows of corn planting equipment to twelve rows of and
receiving equipment that type of thing that way we don't injure those outside
rows of corn or it may even destroy those outside edges the corn where the
equipment we run we want to also consider herbicide persistence and
carryover before we're interceding so we want to plan our herbicide applications
to allow us to intercede cover crops in our research we have relied upon
glyphosate alone most often the cases that we will really want to incorporate
a residual herbicide into our program however we don't just to prevent injury
to our cover crop but for a best management practice out in the farm
landscape absolutely use a residual herbicide and make it work with recover
drop in your seeding program the easiest way to think about how to make this work
is if you have a residual if you a weed problem that's of a broadleaf
weed species think about using a residual broadleaf herbicide program
that doesn't have any grass activity and then you can intercede a grass cover
crop if you have a really bad grass problem use a grass Raziel herbicide and
use a broadleaf cover crop to intercede there's different ways of making the
system work and there's some really good research out there from Penn State on
some of the herbicides that work in this system we think about using interceding
in organic production we're gonna want to intercede and we're doing our last
cultivation pass so you think about mounting some of the specialized
equipment on our cultivator and combining field passes a great way to
save some time and save some fuel I mean a great way to get a cover crop
established out there on the landscape we look at modifying our drill how we
modified our drill is we took some row units off the drill to allow for those
three seed units to be placed within that 30 inch row of corn that allowed us
to easily intercede across these three rows of corn here are three the the
three rows of corn were interceded then during that 10 foot pass obviously we
did have some Simba's areas where were not interceding so we'd have to run our
drill back through one of these other rows to fill in those areas but again
it's all about mashing that equipment size to planter size to prevent any crop
injury we look at some of the species that work the best and are interceding
trials we've had good luck with red clover and corn grain and corn silage
that's by far the best cover crop to intercede we look at winter rye we've
had really mixed results with winter rye and corn green we've seen some corn
grain yield implications we've also seen some cover crops that didn't make it all
the way till harvest silage corn however we've seen some really excellent stands
of winter rye and red clover both also to consider radish and in ryegrass to
add into the inner seeding mix we've seen some limited success with those
species as well one way interceding we want to use best management practices
for depth and rate of that seed and we ensure that good seed to soil contact we
start to look at some photos from our interceding plots our very first photo
here's of our oats and peas still alive at this point but it's
struggling we want the interceded cover crops to look tough that means they're
not competing too heavily for resources with the corn crop but yet they're
focusing on root development but again this is probably a little bit too rough
we move on to the next photo this is red clover again a tough standard red clover
but this is going to stick around this is focused on some root production and
surviving that canopy fresher radish a decent standard a dish and then a really
nice looking stand of winter rye we move on to harvest though however in the
fodder covers up all the cover crop biomass we head out in the field and
we're thinking gotcha I don't know if it made it through the
combine past it was a little bit wet at harvest we maybe had some compaction
issues what does that cover crop look like the next spring and we have this
really nice stand of winter rye this is a great success story when it comes to
interceding we had our winter rye out there in the spring already taking off
from underneath the corn residue and gonna produce a nice cover crop to
no-till plant back in to look at a few more photos from summer 2015 then we
have our nice stand of winter rye radish and red clover at this point the oats
and peas mixture didn't even germinate under that severe competition from the
corn canopy so again showing some of the very abilities of the system probably
not a species that we should be thinking about interceding we look at harvest
then we look at our winter rye rash and red clover plots and they look really
nice our red clover pod particularly looks really good nice strong stand of
red clover so we started to look at some corn grain yield and we've done these
trials at Lancaster in Arlington and this data table shows us a few things it
shows us something very far left we show our our plot our treatments and then
moving on we show our years across the top 2016-2017 and then we show our our
seeding method so we interceded b5 we broadcasted a v8 and we over seated to
simulate an aerial application and then could start to make some comparisons in
the bold text indicates that the cover crop was still viable at harvest so you
can see and are interceding and even in some of our broadcast applications the
cover crop was still viable at harvest however I
our aerial applications we had a little bit more variability in crimson and red
clover they were not viable so harvest we look at our yields though none of
these are significantly different so we should really look at how much biomass
was produced by some of these seeding methods to start to narrow down which
method may work best on my farm should I also consider the economics of these
systems and existing equipment that we have to make a good decision we look at
some of the red clover growth that Lancaster these were some broadcasts
interceded red clover plots we have a nice standard red clover here that we
broadcast about twelve pounds per acre one month following harvest we have a
nice stand red clover that's growing through that residue and then in the
next spring we had about 500 pounds of biomass out there on the landscape that
we harvested then for our trial we think about adding livestock into the crop
rotation and how can how can we make this system work for our livestock
producers and this is where we're thinking about interceding silage corn
so we can intercede our silage corn at a time of year work we may not be as busy
trying to manage crops trying to harvest forage this allows us to have a cover
crop then immediately after silage corn harvest that's going to take off so this
photo demonstrates over here on the far right hand side how our nice-looking
standard red clover looks that has been interceded the next spring then that the
spring growth we think about a green rotation we're trying to get away from
our tillage passes so how do we incorporate a cover crop into this
system we think about broadcasting to the cover crop with a broadcast spreader
again if we have a drill that we have access to we could think about modifying
that but that's more on the livestock side of things is where we'd expect to
have our drills on the green side of things we think about maybe having a
custom applicated come in with a fertilizer spreader and spreading our
cover crops and getting our cover crop established it that way and again some
great soil health and soil conservation conservation benefits from having that
cover crop out there for species I think about red clover winter rye and your eye
grass and maybe throwing a few radishes in there in the mix but again we're
likely going to see little above-ground growth
out of any of our cover crops species until the following in spring so that
concludes my presentation I'd welcome questions at the email and phone number
on the screen and please reach out to your local Extension educator for more
information
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