Managing Phosphorus for No-till Corn and Soybean

Managing Phosphorus for No-till Corn and Soybean


(Music) And I’ll be taking the first part
talking about really phosphorus management and no till corn and soybean. Jason Miller with NRCS will be doing stuff
on how own sampling. So that’s how we’ll work it, kinda half of
each and so none of us will get too tired then. And so I guess we will just follow the outline
and we’ll look at some of these plots that Dwayne set up for us this spring and on starters
and phosphorus application and we’ll look at that. I’ve got only one replicate there that’s labeled
but I think we can see some things in that too. And so really what is a starter, we got a
concentration of nutrients close to the seed, that’s what I consider a starter or pop up
some people will call it other names too. But that’s what I call it. And it gives us that rep, sure okay, that
gives us that rapid uptake especially of phosphorus right away that we’d like and by the primary
root system and that’s the whole idea especially under stress conditions. Boy if it’s a good year or good spring. You really don’t see that much phosphorus
starter response. But years like this year, it’s cool and cloudy
for long period of time, we see a pretty good starter response and this is one example of
it here. That I got north of Pierre and seen that early
about three weeks ago too and pretty much, it’s pretty much due to the phosphorus that
he had fairly close to the seed. Ans so we’ve got some back in Brookings too
that pretty good responses this year. But it’s too cool, too wet, too dry, compacted
soils or any kind of stress that limits that root growth. That’s when it’s particularly important to
have those nutrients, especially phosphorus close. We need that intake of P fairly quickly in
that plants life. So that’s really important but other nutrients
you see in there are nitrogen, that usually comes with the MAP or the DAP or the 1034O. We don’t need a lot of N, especially if you
put on before you plant for corn or whatever crop. So or if you side dress that little bit of
N that comes with the phosphorus or that is there already is usually sufficient to get
you by. So we haven’t seen a lot of response to starter,
starter nitrogen. And a lot of times you will put in sulphur,
if you’ve got sulfur problem, we’ll talk a little more about that and maybe a little
zinc. If you got zinc problems, I usually tell people
put on five, ten pounds broadcast some way just take care of it and don’t worry about
the starter zinc unless you’ve got some nobby hills that are high in calcium carbonate to
tie up that zinc with a higher PH. I’d put a little starter too of zinc on there. And potassium, again if you got K deficient
soils, then it’s nice to have a little K in that starter as well. Although you need most of it in some other
application method. And so why important or why do we need it
again, like I said stressful conditions is when we need that nutrient close and that
early P uptake is important and phosphorus is not very mobile so that root growth has
gotta get to it. And when we talk about that root growth, see
the primary root. Just pulled these up out here. This is coming of the seed right here, that
primary root and it’s going off at about a 45 degree angle and then about the third leaf
stage it doesn’t do a whole lot anymore, the nodal roots, the secondary roots that take
over. But it’s really important, up to the V-3 stage
about getting the plant off to a good start. Is that mike working okay? Okay. And you see that chart we’ve got here, you’ll
see this early growth response a lot with starters but it doesn’t mean it’s going to
yield more and we summarize 61 starter studies that we did over the years. That top graph there, you’ll see it’s very
low, low phosphorus soil test, medium to high or very high is what that stands for on the
bottom there. And that first chart there on the top is measuring
early growth response. And you can see two-thirds to a half give
a pretty good early growth response. Even if it’s very high phosphorus, we see
some of that early growth response. But when you look at actual yields on the
bottom, bushels per acre yield, yeah if you are low in phosphorus, you tend to get pretty
good yield increases. Moderate in that medium to high category but
very high. It’s really averages only one bushel and most
of the time, you don’t see it. It does about tasseling time you see a lot
of these evening out and you don’t see it. I still like starter though, not a lot but
I still like starter even on our very high, if you are really high like 30-40 parts per
million Olsen you probably don’t need anything but if you are under that, I’d still like
to see it just because you get that early growth response, shades weeds, it prevents
some evaporation so you get that row cover and so and some years it does give you a yield
bump but not too often. (how many parts per million is your medium
or high) Um, medium and high vary with your soil test but with the Olsen you are talking
about a medium of 8-11 and high up to that 15 part per million. Very high is over 16 so it, that’s where we’re
at. The source of phosphorus there on this chart
down here, really doesn’t matter, if we are talking liquid, poly phosphate or if we are
talking dry ortho phosphate, this works was done by. So where in the heck were we. Starter sources of P, it really doesn’t matter
if it’s liquid or dry. They’ve shown that quite a bit over the years
and where to put that starter, we mentioned that band near the seed and yeah we looked
at this primary root and coming off that really a 45 degree angle and that’s what most of
them do come out and they talked in the early days well if we put a band two inches below
and two inches to the side, that should be about just right or that root to intercept
that and get that early season growth. The problem is putting it almost four inches
deep, it just doesn’t work in a lot of years. It’s just too dang wet and it can muck it
up, it can disturb your seed zone so hardly anybody does that and so that’s the problem
but over the years we found that boy if you just get it near the seed, it does as well
if not better than a 2 X 2. But there are some problems there that we
will talk about there too. This chart up here on page two, band is more
efficient that some work we done at Watertown, really it was only three or four years in
no till but it’s an average of two year and if you look at the different rates and its
yields there on the y axis. Zero had 157 bushels per acre those two years,
where he put 20 pounds of phosphate on as broadcast, it didn’t do much better than the
check but where we banded it 2 X 2 at planting, bumped it up 10 bushels at 167. Now when we bumped it up to 40 pounds per
acre, there the broadcast looked pretty good. It looked about as good as the band so it
tells me we probably can get by with a little less with band if we have to. The problem with that is if you are trying
to build or maintain soil test, 20 pounds usually isn’t enough for our yields. And so if you got real high soil test, you
probably only need 20 pounds with a starter. If you got lower soil tests, we usually are
trying to at least maintain what we are taking off with our yields so. You can do that for a couple of years if you
got real high phosphorus prices, you can cut back and go to a band for a couple years,
it’s really not going to hurt you any in yield or soil test level. But after that you probably drop in soil test
levels. This next chart is some work that we did over
the long term with long term no till, over about 10 years and a corn-soybean rotation. What we are showing here is just corn yields,
either at Beresford or Brookings, at different rates. Zero, 20, 40, and 60 pounds of XO phosphate. We either put that broadcast after we planted,
we didn’t want any incorporation and we put it right after we planted or we band applied
it in 2 X 2. And again this was long term no till and if
you look at those yields between broadcast and band, there’s not a lot of difference
and so broadcasting that on long term no till, we feel works pretty well and the reason we
think that does is the mycorrhiza fungi attach to the roots with most crops. They act as root extension. They can actually feed at the surface, even
when soils are fairly dry. They attach to no till plants very very quickly
but if you are on a till situation, the tillage destroys some of those hyphae and it takes
longer for them to establish. So get in that early phosphorus with no till,
still works with the broadcast application and I would recommend that if we got really
good slopes where we could get come run off or erosion that might take that broadcast
P with it. For a lot of no till fields we don’t have
a lot of problems with run off so that is an option, that is an option for no till where
tillage it really doesn’t work at all. There’s no reason not because we can till
that P in. Yeah where to put the starter, we mentioned
2 X 2 right with the seed or close to it or like Dwayne does, he puts it in a planting
v after the seed firmer wheel goes over it and so there’s a little soil left that falls
in but you are still getting that P starter fairly close to the seed. You can, some work shows putting it below
the seed may be have an advantage or even above the seed. We did some work, this lower left hand in
the chart there where we put it either with the seed or two inches away, four, six, eight,
all the way up to 10 inches away from the seed. It was about horizontal, the same depth as
the seed, about two inches, not quite. And this measured early growth, early growth
difference, we just measured the dry weight and you could see there, no P had gave us
the less weight but then the 10 inch gave a little better but no much. Then it goes right on up, six, four, two inches
and the best, where it gave you the best early growth was when we had it closest to the seed. Right with the seed. So, probably even better than 2 X 2 but it
really was like two inches over at the same depth. Then we also put it three inches below the
seed, kind of to mimic that strip till. You are putting that phosphorus below the
seed and that didn’t do as well as we had expected. Really need to put starter even if you are
strip tilling. You are just putting most of that phosphorus
down deeper for later uptake but not for that early uptake. But we seen all that yield growth, we didn’t
see any difference in yield. Even though phosphorus was really low that
year, there was no difference in yield, they all about the time of tassel. They were about all equal growth and they
all produced the same. Then Dwayne and Walt Rydel on that next chart
they put some phosphorus at different placements with the seed, 2X2, and surface band over
the row and looked at P uptake, early and then yield. And yield, the surface band right over the
row wasn’t as good as a 2 X 2 or with the seed. That’s what you would expect in most situations. So, that was some data there. Lot of people ask how much starter you put
on and usually 15-20 pounds to apply is plenty. You don’t need a lot to get a boost and so
that 30-40 pounds of MAP, it doesn’t take a whole lot. And then the next question is if you got low
testing soils you usually got to put 60-70 pounds of phosphate on them and people say
well as long as I am putting starter on, I’ll put it all on and that’s phosphorus salt too,
it’s not as bad as nitrogen or potassium, it can influence germination too with too
much of that there. So a lot of times we cannot put it all on. But there is a number of factors that do affect
if you are going to have problems with germination and fertilizer next to the seed. One of them is crop sensitivity. As we all know, soybeans are pretty sensitive
to those fertilizer salts. Wide rows especially we can’t put a lot of
P with soybean. Where’s corn is one of our least sensitive
plants and we can put a lot more phosphate with that. So an actually small grains are just below
corn as far as sensitivity but since we have narrower rows, we can put a lot more because
we’ve just got that phosphorus or fertilizer diluted a lot more than if we had wider rows
like corn. How much you scatter that, if you got a wide
furrow like we used to have with some of these small grain seeders, you scatter that fertilizer
over a bigger area and you are just diluting it. If you just got a small v notch like we do
with most row crops, you are concentrating it pretty good. Row width makes a difference. Wider rows your are concentrating more of
that fertilizer with the seed. And distance of fertilizer from the seed,
each time you got a buffer there of soil between that seed and fertilizer, it makes a lot of
difference. Getting by with actually more fertilizer than
if you just putting it right with the seed. And as Dwayne was telling us, most of the
planter’s today do not run fertilizer directly in the seed. They are putting it, like he’s doing where
a little soil falling on top of that seed and so we don’t have as much of a problem. Rainfall after planting of course makes a
difference, it of course dilutes the salts. The next chart there PH makes a difference,
soil PH. If you got a high PH soil, it’s usually more
damaging if you are putting on something like DAP, 1846O. It tends to form ammonia in high PH situations
and it’s a little more toxic than NAP would be.So if you got a high PH soils, I’d sure
recommend NAP if you can get it or N34O, a liquid source. Soil texture, organic matter, or CEC soil
tend to have more problem. One thing they tend to be sandier and they
have got less moisture there, dryer conditions, more concentrations so. And of course fertilizer rate, the element
and the analysis will make all the difference on the, how much you can apply. Some of our data, starters can delay emergence,
I compare MAP and 1034O and it how much it delayed a seedling emergence.Typically always
when you put a fertilizer down, it will delay a little bit of emergence. Sometimes you can’t measure it but if you
look at it, you can see it. There’s a couple of times where it actually
did increase emergence but that’s really unusual and I can’t explain why it happened but maybe
we got something mixed up but there was a couple times that I’ve seen that. But usually it delays it. And if you look at MAP at 12 1/2 pound phosphate
rate, it delayed it only about half a day, that ‘s about as much as we could measure
but 1034O didn’t seem to do anything and if you got a higher rates like 50 pounds of MAP
or 25 pounds of phosphate, that delayed it about three days emergence. And if you had the whole field like that you
wouldn’t really even notice it but it did delay it from the check, that much. 1034O was about one and a half days. Now we think dry fertilizers are a little
more toxic is because when a pellet falls down there by the seed, it tends to dissolve
slowly and those salts are concentrated right there. Where you put on a liquid and it tends to
disperse as soon as it hits that soils and so a little less salt effect is what our theory
is there. We see that in the lab or in the field. That less effect from some of the liquids. Some of our liquid starters are the lowest
germination problem, with some of those. And 1034O is one of the good ones, you get
a little phosphate there and not much salt damage, germination damage. This picture down here, I don’t know how many
of you use that but that’s a calculator trying to with different crops, different fertilizers,
how much we can apply. How much we can apply with the seed, with
different field conditions, moisture, row width and that sort of thing. You can estimate how much you can put on and
so a lot of people use that, we are in the process of updating that with some new information
that we got for different crops and fertilizers. And so but the websites there you can access
that. Now a little bit on the starter study that
we got here and talk about that. Some soil tests that Dwayne took this spring
actually indicated a really low phosphorus test and he’s trying to pull these tests down. Only three part per million and so it’s fairly
low. So i’d expect a fairly good phosphorus response
from the phosphorus that’s out there. And then he’s got some pictures of the planter,
he’s graciously pulled the planter out and we will take a look at that how the fertilizer
was applied. But there is really four different treatments
he put out here and treated in four replications, four times and one of those was P width, the
lower chart down here. P width, close to the seed and like I said,
that was put on right between right behind the see firmer and we will look at that on
the planter, either zero or 35 pounds of MAP which comes out to about 18 pounds of phosphate. Then the other was the side place application
of phosphorus where most of the P for the plant, he’s giving that starter effect by
putting it close to the seed and then he’s putting his nitrogen and most of his phosphorus
about three inches away from the seed with a fertilizer opener and so we’ve got combinations
of those four different treatments. Those are listed there and that’s what we
will take a look at here in a minute. If this were a sandy soil, he’s putting about
228 pounds of urea and 57 pounds of ammonium sulphate in that side bin. Comes out to 117 pounds of N, 14 pound of
sulphur. If this was sand I would be a little worried. I guess one of the reasons are is this chart
we got down here, this was on a heavier soil again, it was on a fairly moist soil. We put urea which is again what he’s putting
in the side bin, which is pretty toxic to seed because it forms ammonia, which is pretty
toxic for germination. But what we did there is just put the urea
right on the seed or moved it over in inch increments up to, what is it, four inches
away. Just to see what we would get for germ and
emergence. Of course right with the seed, it really knocked
the heck out of it as you would expect. 100% emergence with zero rate and only about
25-30% with the high rate or urea there. Now we moved an inch away, 30 pounds really
didn’t effect it at all. But the higher rates still did, that wasn’t
far enough. When we moved to two inches away, pretty much
all the rates except the high one, that knocked it three to four percent germ at 120 pounds
of actual N. That’s almost 270 pounds of urea, quite a bit of urea there. And it didn’t have a huge effect at two inches. At three inches, there was virtually no effect
on that, at three inches away. Again that was a heavier textured moist soil. Dry sands some spring, I would be a little
bit afraid of putting that much on that close. But I think for these soils, we are plenty
safe with the rates he’s putting on. And so with that, if there’s any questions,
I will try to answer them, otherwise we can move over and take a quick look at the plots
and then I will turn it over to Jason. Oh just one thing while I got you here, anybody
seen striped corn this spring? Anybody seen some of that? Quite a bit of it around. Yeah that’s a good point, did anybody not
see it? There is still some around in the north part
of the state and the eastern part of the state and you see it but a lot of it is disappearing
but you can see it here. This was taken up by Gettysburg and two weeks
ago it was really bad. It was yellow and really striped but it’s
starting to come out of it. And so this is characteristic of sulphur and
typically but there’s a lot of springs we see it. It doesn’t hang on as long as it did this
spring but we were unusually cool and cloudy and I call it more of an environmental effect
than a sulphur deficiency because it usually disappears once your soils warm up and it
goes away. Now the exception will be the sandy soils,
low in organic matter, eroded soils that are low in organic matter that hangs on and hangs
on and the plant is still pretty striped there, that could be a factor. But we’ve seen this this spring kinda where
we treated with sulphur, we see the striped so I don’t think it’s really a sulphur problem
and I think most of these plants, on the heavier texture soils will come out of it just fine. And it, really the same thing happened in
2003 and we had sulphur plots at Brookings, at Beresford and sulphur plots looked pretty
good but we seen striping in corn all over the place and but it came out of it and the
sulphur plots didn’t yield any more than that ones that didn’t have sulphur, so most years
it will come out of it. (inaudible) No soybeans, harder to tell nutrient
deficiencies, especially like phosphorus. You will see a little growth difference, you
get plots but if you get the whole field that is mainly phosphor deficient, it is really
hard to see but you can get five, ten bushel on low or very low phosphorus testing or responses
on soybean. The biggest thing in soybean is probably IDC
or iron deficiency chlorosis and I’m beginning to see that in some lower areas that can be
kind of wet. It’s something you really got to take care
of before you plant resistant varieties and Soygreen would, it’s an ortho kelated iron
has shown some promise to applying that within those areas. And so typically on soybean that’s really
the two major ones. The sulphur we don’t see it much, see much
response in soybean at all. There could be exceptions in real sandy stuff
but those are the main ones in soybean. And of course if you are growing soybean on
ground that hasn’t had that for seven, eight, ten years of course you need to inoculate
because you will see nitrogen deficiency on some of those as well. Any other general questions? Let’s go in the hot sun and see if we can
see a rattlesnake or whatever out there. And so if we’d looked at this earlier we would
have seen more differences but and the hail of course really did some problems too. Now you always see one row in each path that
doesn’t look as good and Dwayne said that one had it’s nitrogen and phosphorus plugged
and they wasn’t getting anything to the side. So we are getting a nitrogen response as well
and at this time, you’d expect to see that too. That really shows up there. Though but you see that in every path. So that was that treatment. This one had both. 18 with the seed and the 50 P so it got both. Again I don’t see a lot of difference between
those two and like I said, if we’d looked at it earlier maybe you could have seen something
but at this stage they are well within that 50 pounds of P on the side and I don’t see
a lot of difference. But again the stuff we are putting on the
side, to help with the phosphors needs here in the season, the growth is with the 18 pounds
with the seed pretty close to it. (inaudible) Well I think here yeah because
we are pretty low on phosphorus. I think if you were high in phosphorus you
wouldn’t need that 50 pounds of P. You would lower your phosphors level but if you are
in medium soil test level, you really need a little starter, that’s about it. And so it gives your some options too. If you build your soil test up a little bit,
you don’t have to worry about high phosphorus prices because you can put a little down as
a starter and that should be good for a couple of years.This one here only the width, didn’t
have any to the side and that really to me looks pretty good. This one here, the check where it didn’t get
any and I look at these two I see a pretty good difference there. I don’t know if that’s real or variability
but this strip look a lot better to me than any of them. Defiantly we need P, like rate of nitrogen
is critical. Rate of phosphorus a lot of times isn’t. We get a pretty good bang for a small amount
of P but eventually it’s going to lower your soil test, that you don’t put enough on and
you are removing more and then you could run into problems. It’s modified almost every year too. He’s got really good ideas I think here. His fertilizer openers up front, single disk
openers where he ‘s putting most of his fertilizer is N and his phosphorus is offset three inches
from the seed. I ask him about wet soils and he said yeah
he bumps it up a little but he’s still getting that covered with soil and that’s important
I think. Then the starter, what I call starter are
going close to the seed, his seed firming wheel is here, that’s going into the v notch
and then the dry is blowing down here and so you are getting some soil probably over
that seed but you are still getting quite a bit of fertilizer close . There is probably
some that ends up on the surface too but still enough to do the job and then the closing
wheels are covering a lot of that so that’s essentially putting on his fertilizer. And I like the ideas that he’s got urea covered
because of the volatilization and a lot of times we don’t run to it but this last year,
it was so dry in the spring for so long, guys told me particularly in central and western
part of South Dakota, they put their wheat in early and they didn’t get any rain for
a month and they thought they lost most of there nitrogen and I believe it. Because they didn’t get any response even
where they put on AGROTAIN which is a urease inhibitor. But that gives you maybe 10 days of protection
but if you don’t get rain in time you can lose that N too. We were so hot and windy, warm for that time
of year, those are the conditions you get that volatilization and so we can lose it. That’s what I like about this system here,
putting it on at planting with that phosphorus and away from that seed. Guys will tell me but gee they don’t want
to fill up that much when they are planting. They just want to plant. Yeah there is something to that but agronomically
that’s a good way. I mean if you are gonna lose a lot of your
N and not get benefit from the starter. I think it makes a lot of sense to maybe take
a little more time and get that on. But that’s how he’s got it set up and seems
to be working well. (Music)