Articles, Blog

Adjusting Nutrient Management to Modern Corn Hybrids

August 10, 2019


Well, thank you very much It’s a pleasure to be here. It’s my first time speaking in Alabama and I feel a little bit out of the water in the sense that My family history is in Ontario Canada, and I have three or four brothers at farm three or four meaning Yes, I have four brothers one of whom farms part-time, so I don’t sometimes know whether to count that as a farmer But it’s also an interesting thing in the sense that I’ve always been a student of corn going back to my university days And I also Am very passionate about farmers because farmers are the ones that really put the system together And they put the system together for you know the current genetics at the time on their soils with the best possible management advice and and sometimes that passion for Production is is sort of what drives. You know being satisfied with the yields that you got for a given season for a given hybrid etc and so I also Have the have the opportunity to do not only work at Purdue where have been for the last 16 years But I also have an opportunity to watch over the shoulder of my son who is farming in Texas In irrigated agriculture, so I don’t profess to be an an expert here. I’m still Fairly young in the sense that although I’ve worked on corn for 30 years I’ve got a lot to learn and so I’d be appreciative of your questions as we go forward here In the research that are going to talk about today. I’m going to say that my context essentially is one of trying to Do the best possible job on the production side but not forgetting the environmental side and so for most of my career now? I’ve kind of promoted the concept of no-till and stripped tail corn production systems in order to save soil and So we’re regardless of whether we’re looking at nutrients or hybrids, it’s important to be part of the sustainable system first of all because Lord requires us to be stewards, but secondly because of the fact that we want to essentially enhance the Soil health it’s a very popular term of course at the moment And so what I’d like to do is to start off with a bit of context In Indiana, We have Certainly both forests of soils as well as Prairie soils and when I came to Purdue 16 years ago I was able to inherit one of the long term tillage plots that have been in existence since 1975 and that study is one in which we’ve been able to compare no-till and very strip till and and other systems so this is a dark Prairie soil and And these are our plots, 150 foot long, 30 feet wide the average strip till Corn is here in the grain and it’s averaging about 210 bushels per acre and a corn soybean program and it’s everything about 190 bushels per acre in continuous corn But the main reason for showing this slide is essentially to say that There’s nothing better really than growing corn and rotation the continuous corn yields continue to suffer at the rate of At least 10 and sometimes as much as 20 bushels or more and that was also true this year when we had 270 bushel corn Because we had a much higher productivity season But one of the things that any system does on farms is that it affects, sort of, the soil properties not just a structure or the relative amount of wind and water erosion But it also affects nutrient stratification And so as we think about trying to push higher yield levels we need to think about nutrient stratification and whether or not the new roots for any particular stage of corn growth are actually in a zone where Nutrient supply is adequate and so for instance, in this experiment, we’ve been doing moldboard plow chisel plow strip tail in no-till for many many years And you can kind of see that in it can newest notail program for corn-soybean There’s about a three to one ratio for soil phosphorus And the top four inches compared to the lower four inches but you also see a similar degree of stratification not quite a severe in a chisel plow system and Indeed anything other than a moldboard plow will lead to stratification now In a sandy or soil situation you wouldn’t have quite this extent of stratification And it’s also true that everything depends on how much rainfall Do you actually receive for how much irrigation water do you apply? This is true for a silty clay soil which holds on to P and K fairly tightly For a situation where we have 40 inches of natural rainfall per year and where there is no irrigation The influence on soil test K is almost exactly the same in terms of tillage systems fairly uniform Averaging about one hundred and forty parts per million. This is parts per million down here, so this would be the same thing as two hundred eighty pounds per acre fall to the plow stratified and no-till stratified even more And so that’s just something to think about as we think about nutrient application Programs because if your only program is one of broadcast application, then for a given soil and a given rainfall and a given cropping program, where you’ve got removal from these different depths and where you’ve got the depositing again of The Stover let’s say that’s left over on surface. You’ve always got a recycling going on and The amount of stratification that you have is not just dependent on yield levels But it’s very much dependent on where you’re actually placing the nutrients themselves and so for For several years. We’ve been looking at nutrient placement options other than broadcast and and sometimes those are part and parcel of a strip tillage program where we’re essentially trying to do some fall strip And here you see what we were doing in November. That’s one of the problems with With Indiana compared to Alabama’s that we get snow and we have to do Frost and all of that sort of thing But it does mean it’s kind of a pretty picture For what we were doing here in November so the the interest really is in in one of applying Phosphorus or potassium at the same time in a fall program in Indiana we do not recommend fall anhydrous application But in states to the west of us that happens to a greater extent. I don’t think it’s a very wise stewardly management of nitrogen necessarily But it is a response sometimes to achieve for price of nitrogen in the fall as well as an opportunity to get Some of the spring work out of the way And at the end of the day What I’d like to do is most is perhaps not just learn about corn but train graduate students And and and that to me is is one of the most fulfilling parts of what I do and so put a plug out there if you’re 22 or 42 60 to maybe it’s a little late to start graduate school but you know anywhere in the range of 22 to 42 if you’re looking for a grad school program come to Purdue we we promise to boiler boiler up Why that didn’t compress very well anyway modern hybrids that’s really what you asked me to talk about and And what does that mean so modern hybrids as? The previous speaker Ron also talked about are going to be perhaps especially with dirt on hybrids going to be more resistant to water stress They’re certainly going to be green longer and so that’s shown here Compared to hybrids that senesce much earlier in the grain feeling period on the right hand side And what does that mean for nitrogen? Options in terms of timing and and rate, and that’s a little bit of what I’m going to be talking about today And this is sort of one of the high clearance options in this case with Coulter’s so that you can inject Let’s say liquid uan between rows even fairly late in Vegetative growth now all of this starts from the presumption that hybrids are different today than they were– 20 or thirty or forty years ago It’s a challenge in agronomic research as you know to always have relevant research to today’s genetics because today’s genetics change so quickly and And you saw that with dr. Ron’s program earlier is trying to use you know modern pioneer dekalb or Syngenta hybrids To reflect on you know how do they respond to management in a particular environment? But I I want to go back a little bit and essentially say that one of the things that’s fundamentally different about today’s Hybrids in general is that? They are higher yielding of course which is kind of what you expect But they are also Much different in their nitrogen timing of uptake and their efficiency of utilization of nitrogen so We went through all of the known literature around the world and divided the corne results that we found from published literature from before 1990 and then in the period from 1991 to 2011 the Average year that was the average for the results of the trials that were reported was 1984 from this 50 year period and the average for this 20 year period was actually 2001 right in the middle nitrogen rates in these various trials Had a whole range 0 to 500 pounds But the average for what we’re reporting here is 125 pounds the average density is 6,000 plants per acre higher The average yield is 30 bushels per acre higher And what are the main differences the main differences essentially are that we are producing more grain per unit of? Nitrogen taken up in the plant, so we’re now producing an average of 56 pounds of nitrogen Of grain, I should say for every pound of nitrogen taken up above ground And then the other main thing that’s occurred is the fact that while we’ve increased Yields and while we’re being more efficient in producing grain per unit nitrogen is that our grain? Nitrogen concentration or in other words a protein content has gone down as has our average Stover nitrogen gone down so But I don’t want to pretend that everything is just so cut and dried and there can be a lot of variation and how much yield is produced per unit of Nitrogen taken up above ground so this is only looking at the modern period here of 1991 to 2011 we’ve got 2000 data points in here from all over the world and this kind of shows that say for n an average yield of let’s say 200 bushels per acre going over here that that we can Essentially have quite a wide range in the actual nitrogen uptake in terms of pound per acre basis so you could have as little as a Whole plant uptake of a little bit less than a pound of nitrogen per bushel, but you could also be requiring as as much as 1.6 pounds of nitrogen per bushel so this range is Quite broad and what what accounts for that a large part of that is accounted for by number one there are differences among hybrids even within a seed company for a particular year even within a maturity and then secondly there’s a huge impact of management on in terms of the responsiveness of Of corn to how much grain do you produce for every unit of nitrogen you take out and and some of that is the plant? Population some of that is planting date and so there’s a whole host of factors that go in so when we think about being stewards of the nitrogen to Keep it going into the plant instead of disappearing off into the environment we have a large range to play with in terms of thinking about modern corn hybrids and so That brings us around to just how do we put on our nitrogen today? And are there options to consider if we’re thinking about being more responsive to hybrids Taking up more of nitrogen later today than they did before and so here are sort of you know the four Options that we we see the most of at least in Indiana And that is essentially fall pre-application normally with anhydrous ammonia or my son here in Texas spring pre plant or at plant with which takes a lot of normally liquid and and and it’s not so nice from a planting point of view because you’ve got to slow down so much to refill the nitrogen or a side dress application So I’m going to stop here from on and just I want to get a feel for how many of you are doing eighty percent Or more of your nitrogen pre plant just raise your hands. How many are pre plant with eighty percent or more of their nitrogen? Anybody in that category okay? How many are? eighty percent in or or more in a side dress application Then is that the majority of you, okay, I want to know for those of you that are in sort of a You know side dress or after plant phase how many of you are? Doing two applications are there any that are doing to post planting applications, so there’s some of you that are doing okay? There’s more of you that are doing to and I think that’s sort of the direction that Represents perhaps the biggest efficiency gain that we can do with modern hybrids The previous study that I talked about is It’s kind of like a snapshot of what’s out there the problem with that study is that it took a study. That was done Let’s say in North Carolina and another study. That was done in Alabama and one in Indiana for a particular set of time so You know perhaps professor a he you know worked at Auburn University those fired five years later wasn’t able to continue And so there is this paper out there what that doesn’t do is that doesn’t compare the hybrid side-by-side growing in the same environment And so what we did a couple ago is we? got some funding from Monsanto’s well some Indiana corn marketing council and we began to side-by-side plant hybrids from different decades going from 2019 60 to 2005 and we planted them at 22 32 and 42 thousand plants per acre at two nitrogen rates 50 pounds to give some stress and 200 pounds for a corn soybean program, which should be more than than adequate and we do a lot of Processing of plants in a trial like this in order to try to capture When is a nitrogen taken up how much has taken up at a different population for a different hybrid? Representing a different era of of production and so it’s a large crew that we put together to do this I’m going to look at just I had eight hybrids in that one I’m only going to condense it down to just looking at the the The three extremes or the four extremes in the next slide And I’m going to look at a situation where we compare 2005 hybrids versus a common older hybrid of from 1975 for the nitrogen rate which should have been more than adequate for corn-soybean of 200 pounds of nitrogen per acre, and this is done with a PhD student And what we’re looking at here is green yield so the two modern hybrids One is a triple stack one is just Roundup Ready isoline only 225 bushels per acre compared to The older hybrid here and in this and in subsequent slides whenever you see gray You’re seeing like an old hybrid It’s just like why do I wear a hat today cuz I’ve got so much damn gray hair They can’t do anything about it. So I covered up so when you see gray think old alright, so that’s essentially what you’re doing so Essentially so this older hybrid here is yielding about 35 bushels lasts And it’s also taking up about 40 less pounds of nitrogen And a big part of that reduction the fact that it’s taking up 40 pounds less nitrogen in the above-ground parts of the plant Because it’s taking up a much less fraction of that total nitrogen in the after Silking period so this is about 38% This is 30% so what that means is if you grow these hybrids side by side the older hybrids are taking up less Nitrogen, but the biggest difference is that they do not continue to take up nitrogen as long in their growth cycle This is hybrid era influence again and again all I’ll bring up the Bring up the old hybrids here in this case We’ve got the same 75 hybrid as well as one from 1967 and again showing the fact that we’ve got a lot more nitrogen being taken up at the In as we go from 50 to 200 pounds and we do with these these older hybrids So that’s one aspect Which is very very important is just how much total nitrogen? Do you need to satisfy the yield levels of current hybrids? But the other one need to think about is the timing of as to when that nitrogen has taken up And some of the most intensive work that we did was essentially to look at various, nitrogen amounts medium low and high This particular case is the starter only? Medium was 100 pounds high was 200 pounds in a corn soybean program And we had three plant populations again because just as is I’m sure a true here in Alabama plant population is increasing these this just shows the results for Indiana we’re Increasing at the rate of about 330 plants per acre per year because the modern hybrids are more stress tolerant in terms of being able to produce higher yields at higher densities, so We plan our plots with RTK precision guidance and We do a lot of work then to try to figure out When is that nitrogen taken up and and how responsive is it to the? intersection basically of nitrogen and plant population and So here in this particular case we’re working with Dow hybrids because funded this particular program 22030 2040 mm and the yield responses averaged over to two hybrids two locations two years and The main thing I want to demonstrate from this is what happens that lets say a hundred pound nitrogen rate We know that our highest yields occur at 32,000 with 200 pounds so that’s shown here But what happens at this intermediate nitrogen rate in this victor case it was 100 pounds plus 20 pounds of starter and essentially What you see here is that we’re producing around? 170 bushels or so at the hundred pound great at 22,000 as we go on to 32,000 this to intermediate nitrogen rate drops in yield and here again at 42,000 that drops even more in yield so that now we’ve got at least a 20 to 25 bushel difference between The 20 mm and the 40 mm So one of the challenges here is that as we go to higher densities? There is a bigger risk? associated with nitrogen deficiency stress so higher plant densities are fine in and of themselves in responsive hybrids for a given water availability But there is an inherently bigger risk of having a yield reduction come about At the high density because in fact That high density corn is more likely to suffer in yield when nitrogen Is deficient and this just shows essentially the green yields in this trial? for a two-year period For the different nitrogen rates red is zero Blue is a hundred pounds and yellow is 200 pounds and essentially showing the rather straight-line relationship between whole plant nitrogen uptake and yield levels So higher yields essentially then require more nitrogen in this particular trial we looked at nitrogen uptake at V 5 V 10 V 15 R 1 R 3 and our six and the and and and this essentially shows How much nitrogen is in the plant at a particular stage, so let’s just say here This is for the 200-pound nitrogen rate. We’re here at about a hundred and sixty pounds of actual land That’s taken up by that particular time, but there’s more to come and in fact We’ve got about 71% of our nitrogen in the plant at silking Which means that we need in this particular trial to accumulate another 30%? during the Period from during the green field period so we’ve essentially got You know another 70 or 80 or sometimes in some cases 100 pounds more of nitrogen to go in after after flowering? and The story is a little bit more complicated than that and that is that reefs more recently I’ve been a lot more concerned about not just nitrogen by itself but nitrogen and it’s consequences for the availability of other nutrients that are also very essential and so In this trial you’ve seen this slide was sort of a small slide that I showed just a previous one But there’s more nutrients going in than that obviously and so one of those is phosphorus By silking time only 45% of the phosphorus is in the plant the the during the green filling period we’ve got 55 percent of the phosphorous going into the plant so the majority then of the total phosphorus is going in after flowering The majority of zinc is going in after flowering At least 40% of her sulfur is going in after flowering 30% of fur bikinis ium and in potassium potassium is the only one that’s sort of out there by itself Potassium is essentially in the plant For all intents and purposes at flowering time it may accumulate a little more But it also tends to lose potassium pretty quickly as you go towards black layer on Corn because it’s beginning to be leached out of the stalks and the leaves already So this is a kind of a wake-up call in the sense that it’s not just Nitrogen need to worry about you need to worry about the Seas long availability of some of these these nutrients And it’s also possible that When you go to higher yield levels to you in fact might in some cases Lose some of that efficiency that I was talking about so we’ve had experiments. Where essentially the Nitrogen efficiency didn’t increase as we continue to go to higher yield levels in fact We’ve seen some situations where in order to get to let’s say 200 bushels We needed to have around one pound of nitrogen per bushel of grain but to get to yield levels of 275 Plus we needed to have something in the neighborhood of 1.2 pounds of nitrogen in the plant to get to those higher yield levels a big part of what we do is Trying in trying to estimate Nitrogen has historically been to measure soil nitrate status So you might say do a pre side dress soil, nitrogen test or you might You might look at let’s say, you know stock in at the at the end of harvest But what we do really too little of is to try to analyze our Plant right at the time when it’s taking up the majority of its nitrogen and that is right around the silking period it’s still You know at that stage. It could be taking up five pounds of nitrogen per day it’s a massive amount, but it’s also during that stage that the plant can tell you whether or not, it’s Sufficient not just for nitrogen But for other nutrients as well and so this is pioneer hybrids 1395 and 1567 growing at a nitrogen rates from zero to 180 plus 20 pounds of starter And this is essentially ear leaf nitrogen concentrations at silk’n time so what I’m going to do. I guess is to encourage Two things today the one would be late split, nitrogen application But for those of you that are corrupt consultants I would encourage you to spend more time in the fields at flowering time absolutely the worst time perhaps to walk through a cornfield But it is the best time to get ear leaf samples in order to tell you whether or not you are in the right range with nutrient concentrations, not just for nitrogen, but for other nutrients as well, and so these are some of the yield results here from 2010 2011 and 2012 which was a drought year for us and our yields didn’t really get above 150 bushels per acre What year leaf nitrogen concentration did we knit need to get to the highest yield levels and and usually that’s here It is in the range of two and a half percent plus Phosphorus is also determined in this ear leaf test and again the the relationships except in 2012 where there is no relationship are positive with ear leaf Phosphorus concentration, this is for a situation where the sole test P was between 20 and 30 parts per million when we sampled down to an 8 inch depth and For a situation where we added starter p2o5 of 60 pounds per acres, so we’ve got fair a fair fairly high dose of starter phosphorus in this situation And I think it’s sort of time that In land-grant institutions at least we spend a little bit more time determining. What is the sufficiency level of? Ear leaf nutrient concentrations at in modern hybrids at substantially higher yield levels And that’s shown a little bit here in the sense that here are the yield levels going from 0 to 250 for nitrogen first of all and This essentially shows that in order to get to higher yield levels. We need to be above about 2.9 percent And that is in fact where the Indiana tri-state Nutrient sufficiency concept is so for this one. This is a published rate 2.9. Percent plus and and here I think we’re pretty good this is phosphorus and Here the minimum level, that’s suggested is perhaps somewhere around 0.3% So that’s shown over here Here it’s potassium the minimum level for potassium. That’s recommended is essentially 1.9 Percent and these results here say that we should really be in the neighborhood of 2.3 plus Percent potassium, and this is the range for for sulfur Compared to the published critical levels in the ear leaves this is the relationships for zinc Mind you all of these experiments are responses to either nitrogen or – phosphorus And here it’s 2 for manganese 20 parts per million is often determined to be The critical level this results here kind of suggests we ought to be Around 30 to 40 parts per million in the ear leaf iron the critical level here It’s at 20 parts per million these results here suggest that we ought to be around 60 or 70 Parts per million and and so on so I guess what I’m trying to build the picture of here Is that the advantage of a nearly sample is that it tells you not just nitrogen? But it tells you some of the sufficiency of some of these other nutrients And I believe we should pay more attention to achieving nutrient balance not just simply looking at nitrogen because it’s the most expensive nutrient And it’s perhaps the one corn is most responsive to but it is very critical that we determine just where we’re at in terms of these other nutrients and so recently we we also again did a around-the-world study on looking at ratios of nitrogen to phosphorus and nitrogen to potassium and This is another sort of balance question for me I mean the the Balance in your personal life tells a lot about who you are and and how you will react to stress And the same thing is true with the corn plant if a corn plant is better balanced in terms of its nutrient Composition for the critical growth stages it will also be better able to tolerate the temperature stress or a Moisture stress, and so this is essentially shows altaïr of looking at nitrogen to phosphorous ratios at the end of the season and the bigger balls here or the bigger squares kind of indicate higher yield levels The data in the red is all from the US and the yellow data is all from the rest of the world 2,300 points in this one and basically the ratio that is ideal in a corn plant for higher yield levels of Nitrogen to phosphorous is five to one at the whole plant level and the ratio that is ideal for higher yield levels in Terms of nitrogen to potassium is essentially one-to-one so if you hear Presentations that say we should be taking out 250 pounds per acre of nitrogen That means that at maturity now, we should also have about 250 pounds of potassium in lis and the corn plant So most of the focus cell on late application is with nitrogen and this can be done In a number of ways it could be done with you know perhaps a bulk spread urea or a ESN or something like that but in our program, we’re putting more of our attention on using injected you am using Coulter systems between rows and the the hypothesis here Is that basically modern hybrids are going to be more responsive to that late split nitrogen and also that we ought to be thinking about Doing a late split as a pre planned program We face sometimes Very high rain amounts Where instead of having let’s say 4 inches of rain a month in June July in August we get 8 inches and whenever you have excessive rain you have losses due to denitrification as well as due to leaching and A side dress program is already a big step forward compared to a pre plant nitrogen program Which is what the majority of Indiana and Illinois and Iowa armours do but even then I think that we should move towards the intentional Late application of 30 to 40 units perhaps 30 to 50 units of Nitrogen so if the recommendation for nitrogen for a particular yield level is that say 200 pounds then I would recommend that we go in the direction of essentially saying we’re going to apply that last 40 or 50 pounds or And we’re intentionally going to apply it later and by later I essentially mean we’re possible to go after the v10 if not after the b12 stage because of this high amount of nitrogen that goes into the plant at later stages and This coming season we’re going to be Working with some producers in Indiana who? Are working with high clearance applicators? and one of those that decided was kind of a unique picture is essentially showing a beauty an Injection system with Coulter’s every second row rather than every row as it’s shown here and in the soybean field So the idea here is be 12 plus Application in high-yield corn and so because of the funding from pioneer Again working with another young lady as a master student shown here with some of the pioneer agronomist And we’re essentially looking at this whole thing of essentially how much yield benefit may there be for hybrids by intentionally going late These are the old hybrids here 20 year old hybrids 33 35 33 94 Here is 13 60 as well as 1498. It’s a hybrid that dr. Ron referred to in his previous presentation and essentially this is the results of 0 plus 20 pounds of starter going up to 140 you can go on to 180 pounds as we’ve done here or 220 pounds as a side dress, but what if you took? Let’s say 180 late? this is a split late application so this would be a hundred and forty pounds of Side dress application at let’s say the b5 stage followed by another forty pounds after b12 and That’s essentially where we got the highest yield so the seventeen bushels higher than the hundred and forty pound great for that hybrid Another hybrid though. Also one hundred and fourteen day hybrid did not respond the same way, so this is essentially just first year and we’re going to be expanding that with other hybrids and on-farm situations is coming here, but essentially I Believe that there’s quite a few hybrids today that are very responsive to a late split in And I think that from a stewardship point of view it makes sense to plan on a late and rather than to only putting on a late in in a rescue situation the rescue situation is you put on the fold Intended rate now. Let’s just say for argument’s sake that’s two hundred pounds, and now you find Oh, I’ve lost a fair bit of nitrogen because of excessive rain And so I’m going to put on another fifty units of actual land At a later stage whether it’s with an airplane or a high clearance applicator And I think we got to be moving away from that because we’re really we’re stewards of the land but we’re also stewards of the air and the water and One of those whole issues is essentially nitrous oxides emissions Into the atmosphere and most of those come from our nitrogen fertilizer applications and we have a responsibility then from an air quality point of view as well as from a water quality point of view to reduce that And so essentially part of the stewardship aspect of the program is essentially looking at let’s say side dress nitrogen application or this late split nitrogen application and essentially studying the loss of greenhouse gases when we let’s say put on a particular rate at a particular time of Uan and when we also add on let’s say nitrification inhibitor, and this is with a sidekick system And this is essentially adding stinked which is one of the products from dow Which is very similar to an serve? Let’s say for an anhydrous, ammonia? Application and what happens with that is if we if we do it well we essentially have much lower nitrous oxide emissions With Instinct in the red compared to you en alone and In some cases that can mean quite dramatic results here We’re losing four pounds per acre of nitrogen with UA n plus instinct to the air above with ua n alone we’re losing fifteen pounds of actual nitrogen per acre, so it’s a lot of loss that can occur and But even a better situation would be never to rely on a single technology always put technologies together when you’re trying to be a steward of the nutrients and so in this particular case we applied the same rate of nitrogen to no-till and chisel plow with and without you en alone side dress compared to UA n plus instinct and We were able to get nitrous oxide emissions down to effectively one and a half pound in the situation where we had instinct compared to a chisel plow situation where we Had about three pounds of nitrogen law says as nitrous oxides now nitrous oxides are just a small part of the total land loss that occurs a lot of this end loss that occurs is occurring in the form of N2 from denitrification, so there’s more going on than than what’s shown here But nitrous oxides are the concern from a greenhouse gas point of view So I’m going to wrap it up here by saying modern hybrids. They’re entirely different Yes, there are big differences sometimes between hybrids, but as a group modern hybrids take up More of their nitrogen post silking they probably take up at least 40 pounds more and in 200 bushel plus corn Sometimes as much as 8 pounds per acre more Post silking nitrogen now makes up at least 56 percent of the final nitrogen in the grain Higher plant densities can really be heard when nitrogen deficiencies compared to lower plant densities no-till can limit nitrogen losses and putting it together with inhibitors and so on are a good thing from a nitrogen stewardship point of view But I think we ought to have a lot more research that goes on into this late split nitrogen application and as well as some of the risks associated with that in terms of damage to corn and We need to focus not just on nitrogen alone But on some of these other nutrients which are also limiting especially when you consider how much of those nutrients is coming into the corn plant after flowering rather than the vegetative period that we typically worry about and so I’d recommend this one strategy essentially doing a lot more effort in in sampling ear leaves at the r-1 stage And so finally side dressing some are all is certainly the superior to pre plant alone enhanced efficiency fertilizers where possible especially in pre planned applications and then late season applications especially Of course where there’s losses, but maybe for modern hybrids Maybe we ought to go to a different strategy of essentially saying we will never put on more than let’s say 50% Of our total nitrogen application at any one time, and we will intentionally use that resource More in synchrony with when the modern hybrids take up their their nutrients and and the nitrogen nutrient in that specific case over the years have had the benefit of loans and Grant funding from number of different seed companies and without their work. I would not have been able to train graduate students or learn and I’d be happy to answer any questions Yeah, I hear you in the sense. There is a challenge in getting nitrogen on the The challenge is less daunting if you’re in the irrigated corn system where I believe that you could still with a r1 sampling still have a nitrogen Application in response to let’s say a fertigation program for the last 30 or 40 units Applied even as late as the as the r2 or even our three stage Because we’re still getting a lot of nitrogen going into the plant if the r2 and r3 stages It is true that from a management point of view sampling at the r1 stage may not be a good strategy for let’s say a You know a situation where you’re trying to apply to be 12 B 14 But it represents the best known benchmark We have today And the benchmark goes you know all the way back against You know datasets from people doing research on corn 40 and 50 years ago And it represents a benchmark perhaps that’s as important for determining the sufficiency of the other nutrients even more so than for nitrogen itself and so I Think that’s why I’m going in that direction is Yes for a rain-fed system Without you know really high clearance capability It’s a post-mortem for the nitrogen, but it’s also a way of telling you whether you are in the Sufficiency range for these other nutrients right at the time when the corn plants taking up the most of its nitrogen We are also going to be studying It’s a very important point you make this whole aspect of trying to determine earlier sampling, and I don’t believe that v6 leaf stages tell us very much at all and So I believe there is Progressively more benefit from later sampling and and perhaps in the long run Maybe what we should be doing is putting more focus on. Let’s say a v10 Application now or a b10 sampling the way that that’s done today is entirely different Essentially because we’re essentially relying on sensors like crop circle and Green seeker. Thank you, and there’s a precision agriculture expert, so she can tell you how to work with that bit the best right? B sticks is terrible right so for that kind of application But that’ll so that is a technique that can be That I would say can compliment a actual And an actual plant sampling right I guess I’m sort of more stuck in trying to Determine as much as possible what the nutrients are inside the plant rather than only relying on a reflectance To tell you but it is true that the reflectance Systems are very effective as provided that you have a true adequate nitrogen control for the same Huayra planted on the same day other questions or comments Thank you, it’s pleasure to to be here and I Also go into a CCA conference for Indiana that we’re Posting for the next few days, and and this is a really important educational opportunity And I wish you all the best in this coming Christmas season But also in in your work at being stewards not just on a financial basis, but on an environmental basis So thank you very much

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