Stop Wasting Money on Nitrogen and Potassium Fertilizer—What the Research Shows

0:03 Okay, getting it going out on Facebook here as well.

0:47 Okay, so we got people rolling in here. Good evening everybody and welcome to our green cover webinar. This is the last in our series, I believe six or seven that we've done this fall, and we're excited to have a really good one to end on. They've all been really good, but this is going to be very appropriate and very timely with the situation that we find ourselves in with high fertility prices. So I think everybody that is either watching this live or we'll be watching it later on YouTube are really going to get a lot of good information here that can potentially save you thousands and thousands of dollars.

1:28 It's really good information, so we're glad that you're here. Just a few housekeeping things: if you are wanting to ask a question, you can ask that through the chat tool at the bottom of your screen or on the Q and A. We will have our presenters go for about 45 minutes and then we'll leave 10 to 15 minutes at the end for a good Q and A session as well. So we'll try to cover as many of those questions as possible at the end.

1:58 So I just want to introduce our panelists, our guest here tonight. Dr. Richard Mulvaney is with the University of Illinois. I met Richard a couple years ago; we were both speaking at a conference out in California, and I heard him present some of what he's going to be presenting here this evening, and I thought, man, that is such good information. We've got to get that out to more people. So we are having him present this tonight, and it really all has to do with nitrogen—nitrogen recommendations, nitrogen utilization and plants, and how many of us have probably been over-applying nitrogen for quite a while. So we're excited to have Richard on board to share that information with us.

2:42 And then, Richard, I'm going to let you introduce your colleague Syed because I just met him for the first time here this evening, so go ahead and introduce him as well.

2:52 Okay, my colleague is Syed Khan from Pakistan. He's now a resident American citizen, and I'm not sure if that's good or bad, but that's what he is.

3:10 Yeah, it depends. I met him back in the mid-1980s when he came here to do graduate work, and he completed that part of his life in about 1991. He went back to Pakistan for a couple years—he was a department head over there in soil fertility. He came back here in the mid-1990s, and he started to work in my lab, and we worked together for about 20 years. He was a very, very valuable colleague, and he has great expertise on the topic he'll be covering tonight, and that's potassium. So I think you'll benefit from what he has to say.

4:02 So you're going to get the 1-2 fertility punch tonight. You're going to get nitrogen and potassium, so it's going to be a really great presentation. So Richard, let's not waste any more time. Go ahead and share your slides there and let's get going. I'm going to hide my video here so that people can just watch you.

4:23 Okay, Keith, and thanks for giving Syed me the chance to share our message on your webinar. We kind of put a catchy title on this, which is relevant to us, especially because it literally took Syed and myself years to escape some of that futility that we're going to be talking about. I think the best way to begin here is with a quote.

4:56 I don't see your screen yet; I don't think you've shared it.

5:02 Okay, there we go. Yup, got it, thank you. So our title is kind of catchy, and it took Syed and myself years to escape some of the futility that we'll be telling you about. Maybe the comments we can make tonight will help you get out of it sooner than we did, I hope. So what I want to do is start with a quote from Will Rogers. I don't know if he had soil fertility in mind when he said this, but he sure could have. And it just makes the point that the problems we face isn't what we don't know, but it's the stuff we know that ain't so. And boy, that is so relevant to the things we'll cover tonight.

5:55 We're going to start with nitrogen and go through some slides on that subject, and then I'll turn it over to Syed and he'll tell us about potassium. So on the nitrogen coverage, we'll be asking a series of five basic questions, and the first of those is about as basic as you can get.

6:19 What is the main source for crop nitrogen uptake? And when I pose this question I'm thinking about corn in particular. So it's going to have basically two sources to feed on. One would be the fertilizer that is now very expensive, and the other would be from the soil. And that's the point of this figure I'm showing here.

6:44 I've summarized the yield data from 47 on-farm response trials that were conducted beginning in the early 1990s and going into the early 2000s. And what I've done here is to choose the sites that had not been manured for at least three years before they were studied. We have a total of 47 of these here in the figure.

7:10 What I'm showing is in the green part of the bar—that is the check yield, the unfertilized yield. And then for the majority of these studies there's an additional component that's shaded blue here above the green, that would be the additional yield coming from the economically optimum N rate at those sites.

7:37 So there are 47 of these studies. I've organized them in order of decreasing check yield as you go from left to right. And you might notice that most of the bars do have a blue bar above the green, but there are some that don't. In fact, there are nine of the 47 that have no blue bar, and that's because those were sites where there was no statistically significant yield increase with fertilization. They were what we would call non-responsive.

8:16 So we look at this set of data, and the most important point addressing the question I posed is that the green bars are pretty much all taller than the blue bars when there is a blue bar. In fact, there are only four exceptions to that in this set of 47 data sets.

8:36 I've summarized the overall picture for this group of sites. The range in N rate was from 0 to 210 pounds per acre. The average optimum N rate was only 85 pounds per acre, and that corresponded to an average yield increase of 42 bushels per acre.

9:02 So from this figure I hope we can get an answer to the first question—that the soil is the main source of nitrogen. So the second question I'd like to put up is: how does that soil nitrogen become available for uptake by a non-leguminous crop like corn?

9:24 Well, we don't have time to go into the details of this—this is like the subject of a college course—but I'm going to give it at least one slide here, and it kind of puts it in perspective, telling us that the key players are the microbes that live in the soil. Now I'm not telling you that those microbes look like this figure, but they are the key players. They run the nitrogen cycle, and they consist of bacteria, actinomycetes, and fungi.

9:59 So collectively, these guys can total up to more than 20,000 pounds in the plow layer per acre. And you might equate that to maybe the biomass in something like 15 cows per acre. Their job is to decompose organic residues. And if they didn't do their job we would be completely overrun—we would be dealing with a massive accumulation of residues, and it would destroy life on earth. These guys recycle that. They cycle nutrients, and one of the nutrients that they are crucial to is nitrogen. They make it available through a process called mineralization.

10:49 So here's the players that make that soil nitrogen available. The third question I'm going to put up is about yield-based recommendations that have been the norm since the mid-1970s when it came into vogue. It's a very simple approach to making nitrogen recommendations, and that's part of the reason why it became so popular. What you do is to take the expected yield goal for corn, multiply it times 1.2, and then deduct from that any appropriate nitrogen credits for legumes or manure. Now, the nitrogen credits especially pertain to

11:39 Corn soybean rotations with a 40 pound per acre credit for the soybeans. So this method came into use in 1975 was the beginning. It spread throughout the US many parts of the world. But do you notice here in this simple formula there's a word that's missing. The word is soil. And we just said that soil was the main source of N for crop uptake. Well that might lead to some troubles with the recommendations from this proven yield method. And sure enough, it does.

12:21 Here we're looking at the accuracy of those recommendations for a total of 102 sites—these are on farm sites. And we're looking at the occurrence where I've grouped the errors in the proven yield recommendation into these different categories and ranges listed here on the x-axis. So the place to be is in the green bar. These are the guys who got the correct end rate to within 20 pounds per acre. Unfortunately, there was only about 20 percent of those of the sites that fell into that group. The others were either underfertilized in the blue bars or much more commonly they were overfertilized. And you can see that with the red bars.

13:14 On average, the recommended end rate for these 102 sites was a 138 pounds per acre. But based on the yield response data, the actual optimum end was only 80 pounds. About 60 pounds less than the average recommended end. So we're looking at a method here that promotes over application of N. And it does that because it undervalues the soil and it overvalues the fertilizer. So there's the yield-based approach. It's not the best.

13:55 So then we look at the more recent option that extension has come out with in the Midwestern states and that would be these mandated end recommendations that go by the name of this end rate calculator that is headquartered in Iowa State. And it also is called the MRTN system—maximum return to N. They came out with this system as a replacement for the proven yield method, the 1.2 method, going back to 2009.

14:28 Here's the home page when you go to this website that I've listed here. And to use this, you're going to be dealing with an economics-based recommendation. And so here's the point of data entry here. You have to choose your region, your state. And the rotation can be either corn soybean or continuous corn. Then you put in some economic numbers down here with the price of the fertilizer you're using—here I've chosen anhydrous ammonia. And we put in the corn price here.

15:07 So what you get is a graph like the one shown here at the lower part of the slide. And you're seeing this gray shaded area that gives you the optimum end recommendation for the conditions that you have specified up here. And in this we're looking at a corn soybean rotation in central Illinois. And the center of the gray shaded area would be 166 pounds per acre. Now that's coming from a database of past N response trials in the area of interest. That's what the basis is for this thing.

15:47 The big advantage is that it reduces N rates compared to the proven yield method and it escapes a big problem that extension had where the escalating corn yields were escalating the end rates. They decoupled it with this system. And the impact is shown here in the bar graph. You get lower end rates with the MRTN than you do with the proven yield.

16:13 Okay so that part of it's potentially good. But there's a fatal flaw. And the flaw is again that the calculator has no way to factor in the soil. It's assuming typical N response from that database of response trials.

16:34 So I've tried to do to indicate what the consequences are with this figure. The problem is that if you have a really good soil, say a manured muscatoon, that shows almost no end response—almost no effect of fertilizer N on yield—you don't need much N at all, if any. But for other soils you need more. The curve is showing a steeper slope. But for the MRTN system, they're assuming that all soils respond here in the central area. They give it an average recommendation. They make no distinction.

17:17 Between a manured muscatoon and an eroded blount there's no difference. So it means that the good soil like the one here in green with their average recommendation gets way too much in, and the poor soil like the blount here in red doesn't get enough. So there you go, manuring isn't factored in. It doesn't make much sense considering that soil is so important to supplying the crop.

17:49 So that brings me to the last question I want to raise: what about soil science? What can we do to make things better in terms of end recommendations? Well, the system that I worked on is called the Illinois Soil In Test, abbreviated ISMT. And it's a very simple test to run. It started out in mason jars and used a pancake griddle for five hours of heating. And the purpose is to estimate the soils and supplying power. We won't go into detail on it, but we have published a number of articles on this, and it basically is measuring an organic source of soil in.

18:36 Now when we came up with this back in 2001, we were interested in evaluating it with some on-farm response soils that we had. And here we have 25 of those sites. There were 12 here that were non-responsive and 13 that were responsive over here on the left side of the figure. And we found it was possible to separate the two groups assuming a critical test value between 225 and 235 parts per million shown here in this green shaded area. And to the right of that we have the soils that did not need end fertilizer—they tested higher. And the ones here to the left that did show a response, they tested lower. And so that was a big deal to us. This kind of relationship had never been seen with any other soil end test.

19:35 We did a lot of work on it. We came up with the idea of soil-based and management, recognizing the critical role of the soil and supplying in. The fertilizer is a supplement. It could be an important supplement, but it's still secondary to what the soil supplies. And then the point about poor soils needing more and than good soils is exactly the reverse of what yield-based recommendations would teach. They'd put the in on the good soils. We would say put it on the poor soils to boost their productivity.

20:16 So we did a lot of work on this, going back some 15 plus years now. And we published a major paper in 2006, and that was exploring the factors that affect recommendations by this soil-based approach. There are many of those factors. One of them was plant population, and we have a little bit of detail on that in the table shown here. We found out there was a fundamental interaction. We're listing here three classes of ISMT going down the first column and two groups of plant population from lower and higher going across the table.

21:00 So within a given range of plant population, as you go down the table, you're getting higher is t values and you're going to need less in fertilizer. The soil is better. And then as you go and stay in a given is and t range and go across from lower to higher population, you can see you need more in because it takes more in to feed more plants. And with the big increase in planting rates over the years, this is a really important interaction.

21:41 We felt really good about documenting this interaction, but truth is it was known long ago from an experiment station bulletin we came across, telling us to plant corn thicker if the land is rich and thinner if the land is old and thin. It's this idea, but now we can put a number on it with the ISNT. The high ISOT areas are the most valuable land you can farm. They give you the option to cut the end rate—you don't need as much fertilizer—or you can boost the plant population to take advantage of higher fertility.

22:19 And so my last slide on nitrogen gives just a brief summary of the commercial interest in the ISNT. It has been used by several private soil testing firms. I list two of those here with cropsmith.

22:36 Actually in Farmer City Illinois and VH Consulting up in Hudson Wisconsin, then I give you three points from Rick van Hoovel at VH Consulting and he's used this extensively in northern Iowa. He says that end rate reductions with this T approach typically start out at 25 to 30 pounds per acre but pretty soon they're up to 50 to 60 with no effect on yield.

23:08 Many fields will show end recommendations that differ by over a hundred pounds per acre in different parts of the field. And finally, many of them have high testing areas where you don't need any N at all. And so he makes the point and I would second it that N should be applied variable rate and this is the way it can be done.

23:34 So with that I will turn the presentation over to Saeed with potassium. Thank you Richard and thank you Keith and all the listeners for the topic. I'm going to give you a couple of slides to explain potassium management.

23:52 This story is also just like what Richard told you about nitrogen. Just to understand a little bit potassium, let me say something that you won't find this in the books: that potassium exists in three pools, three forms and they are very much in dynamic with one another. They can go up toward mineral K and they can also come from mineral tray to the intermediate clay fix non-exchangeable and then exchangeable.

24:19 Currently and also for the last seven decades they are using just a small fraction of exchangeable gain, but this they assume that exchangeable K is a static amount. They just stay is exchangeable, okay, but this is not the case. Potassium is completely different from nitrogen sulfur and phosphorus because it exists, all forms exist is inorganic and when they are inorganic and they don't need a potassium and they also stay as a potassium they never become organic like amino acid amino sugar or phospholipids. They always stay as inorganic and they can go and they can and they are also water soluble. They are not really any, we don't need any microbes to change mineral care into exchangeable so this is a very dynamic. It can increase any time and it can go back if you put fertilizer or any come from plant or any residues they go back to the mineral cage.

25:27 So salt testing estimate just exchangeable potassium but ignore the base K reserves that supply the exchangeable fractions.

25:39 Now to tell the point, this is one of my PhD plot. There was six plots, this is the zero plot drummer soil, very rich corn soybean rotation. They have never been applied K since 1970 and I start working in in 86 on this. In March 1986, so I am just showing you how dynamic it is. I remove the potassium exchangeable scientists in year 86 and then I have the samples. I also took that sample. I was talking bi-weekly samples from six plus on a moist basis and air dry basis.

26:22 So I went to those samples and I remove the exchangeable K and then take the same soil and remove extracted non-exchangeable with successive instruction with HNO3 and I would just take out the same soil. I was not throwing anything in a test tube and put 10 ml of nitric acid one normal for 10 minutes and shake it and then take out the upper solution and keep the soil and if you take instruction number one and 96 I remove 214, then followed by instruction number one 936 pounds per acre, the next was 550 and I'm talking about this is just within hour I'm doing per hour, per hour like this and 550, 413, and that has become 313, 225 and and three.

27:20 So I remove, I'm showing here one to six, but I started up to twelve. I was naive at that time, I thought I can dark down the whole non-exchangeable. I spent all night I couldn't do it. So I went to the 86 and the same sample but in different time, the same plot. 218 exchangeable and then follow the full six section, look at 2696, the same amount, a little bit, it's not going down. Then I went 88 and then ex instruction number one and two and and although 29, 26, this was a little bit up because 88 was a very drought here and you can reflect that 1000 first instruction non-exchangeable, it was not going towards the plant, but it was just there was no water. So if you see this non-exchangeable is

28:12 So dynamic and so huge, it's an ocean, and that created problem for that exchangeable testing. They don't take into account and remember that this soil has been depleted for 13 years and then four years more, 16 years it was a mining, two crops per year, and then it's not going down.

28:37 Okay, and I also are doing a bi-weekly sampling on the same plot which I show you. I would go by weekly in 86 and I was going up to 90. Look at the lower, the chaos and the disturbance and the cyclic nature. In winter they will go up because water was more and they will come out from the non-exchangeable to exchangeable both wet and dry both, and then when crop would come in April they would go down. It's cyclic.

29:09 So one should be very careful if you are doing exchangeable care testing or six inches with even today they are doing it. You are wasting time and every week bi-weekly it's a different number.

29:25 And then the main difference I am showing you that when I started the chat plot in 86 March was somewhere in 150, the lower line. This is my sample, is the what how much moisture is 20, 15, 16, 22, and I would measure the moisture and do the test and then take the same sample and do dry testing. And you see the dryer is always higher, 50, and as time goes by it's increasing despite the fact that we are mining it for the last 13 years. Why is increasing I will explain later on that.

30:05 So in order to check my data I went to the literature at that time. That is any other people in the midwest, similar soil two to one, and you know similar kind of series. So if you see moisture is always lower than the dry soil ponds per acre, the difference is always, the dry soils increase when you dry them, the moist side increase when you dry them so you creating an artificial level which is not the true plant seed. But why it's increasing? Because non-exchangeable, when you dry the clay, water is coming out and it's bring internal non-exchangeable and put it right into the dry soil because they are coming out from moist inside the clay and they bring extra potassium and that's why you get a plus.

30:57 So if you have very close number that mean you are putting too much fertilizer, you collect the click. That's not good, like fire, 140, 144, that guy is under the influence extension and he's putting a lot of KCL and he's collapsing his clay. That already I will show you the slide you change the clay nature from none, from a swelling to a tight light, and you change smack time. That's not good news. I will show a little bit more talk about this next.

31:29 And the reason I was doing it because the extension was and tester was saying that we have problem, give us a fetch factor. I said there is no fetch vector, every number is different so I'll behave differently. This is another soil that I told you I was doing my PhD on six plot so it's 1970 to 83, and they were putting 0 K potassium and then K2O and then 50, 100, 150, 200, 250.

32:02 And then I'm showing you the data. Here all the data I took some sample in January, February on bi-weekly sampling from D-plot and dry it and put it in a bag and then put it in the lid and off in March. After two months I retested dosa and look at this, 370 exchange it's decreased by 106.

32:24 So they are so dynamic that a little bit moisture from the ear in the lab, nothing is the field is in the lip, and look at this how unstable this and how face and exchange is. In the lab they re-equilibrate itself and I get all minus value which initial number was so the exchangeable K is wasting of time. They only generate revenue for the style tester and I don't know how I interpreted for fertilizer recommendation because they never say about what kind of the critical level is and how they recommend it. They say always put fertilizer above the critical level which violate the soil testing philosophy.

33:12 Now if you see we are doing all things testing and everything on the solution. But I'm showing you that how plants behave with the roots, six inches is not the soil, it's a glow which is so the subsoil is a major source of crop uptake. But soil testing confined to flow layer and look at this flow layer is 250.

33:36 Exchangeable profile is 300 and the roots are all going about profile, not just the six inches. Six inches is always two or three inches are dry. I don't know if they can supply anything to the plant, and microbes also go away if it's natural or another, but potassium and every nutrient, microbes and all other water, this is dry in hot summer. So that's not important. The flow there is very important. Now non-exchangeable, how much is there? Look at this: 1000. And I show you sex extraction almost approaching 3000 in a good soil and profile is 12,000. And then 30 is the six inches for mineral and 360,000 is for the pro layer. It's a lot of potassium. How you can benefit from one or two or three bags per day? I don't get it. This philosophy: plant don't need it. It's a self that God designed this system as self-fertilization. Yeah, he knew it. And why it is? If you look potassium, it's involved in 400 plus micro the processes. Tomato control, water control. Taking, it's like a food from the leaf towards the grain, store it. It's all done by potassium plant. And even our system cannot wait for that. They should change the mineral into an our organic potassium. There is no organic potassium. There is everything is soluble mineral. It can quickly go and do the job.

35:11 This is also the importance of profit captain because a lot of crops, they when they you are investing and you put residues, the K is recycled and the recycle is very high. Five, six times more than what you remove in the grain, 260 K content in the whole plant and per acre. And we look at it, the grain removal is 46 per butter, but straw put it five times more, and that exactly what I show you in my five years of study of taking samples. They were increasing without adding fertilizer. This was the source of fertilization from subsoil and residue recycling, and it's water soluble as the rain come they just go out. And that's the reason that you get a lot of noise in the data, up and down, up and down. This is the source.

36:07 Now in order to show you that how you cannot measure the inputs and outputs on the basis of glow layer six inches, this is the data from morrow. We know how much we put and we know how much we removed from the from the yield and now the net change would be what is soil testing if you take six inches sample for exchangeable. Look, there are two plots side by side. We added zero in a check plot in moto plot and the other one got one thousand eight hundred and twenty nine cumulative carrie moon was 796 from the check plot zero and 1511 was from the other one. Net change minus 96. But that's not the case. Look at this: the next soil K six inches initial was 215 and it's increased. It's become now 362. The net change was plus, not negative. And then the same is the case with K removed. In the when we put fertilizer, we added 1511 pounds and then we got net change should be 318. But the initial was 215 for both and look there also you got plus. Where is coming from? For both plot, the majority of end is recycle and coming from the substrate, and it's so much that you will never get any deficiency K. I will show you that later.

37:36 Now this is I say we are doing in maro, not here or anywhere in the world too. We went to the lot of data and dig out these long term trials: four years, 40 years, hundred years. And look at this study period: China, Denmark, Germany, India, Poland, and the studies period and K removed in different crops. We calculated that and initial was this number and then the final was this number and the negative change was there. But if you remove the K, the column K removed, and then the net change, look at how misleading the K testing is and particularly the power in Germany. Look at this: 1914 to 1975, it's also a drummer type two to one milestone. We removed four thousand zero four six and initial was 141 and the final is 110 and the net chain is mine, minus 31. Where is coming from? Subsoil and residue recycles. And our and farmers just afraid, they are so nervous that they would lose and they would lose their everything. That's not the case. That's why I'm showing again and again: there is an ocean of potassium. You don't need that two or three, four bags. You are just wasting your money and destroying your crop. Next.

39:07 Okay, this is a very important slide here. In the books they say that if you are below 300, uh 250, that was their critical 300.

44:46 Grain production in North America four percent show a significant yield increase. Why? Because it was either sandy soil or it was shallow soil or it was compacted soil. There the roots are restricted to the six inches, not yield. So if you do this, let me explain it in a medical term. If anybody doctor, which is a heart surgeon, and he come and you go there he say, 'Hey, 800 people came with heart problem and I appreciate them. Only four percent went to the house to their house and the remainings are dead.' I don't know about the farmer, but I will run from their place right away. Yeah, I'm not staying and I'm not going to their subject to have my heart problem next one.

45:35 Now this is a recent study. One of our students was conducted in close to our farm and essay soybean yield. The data was showing under northern stress they were all depressed in under different telescope conditions. And so that means chloride, particularly and potassium too, they depress various crop to different a different level. And in this slightly clearly showing it, you will lose not money but also depress, which is the hidden cost. People don't say the hidden cost of KCL application.

46:17 This is another slide. Potassium suppresses nitrate because they are both negative. And plant, if you have chloride fluoride with suppressed nitrate uptake. Now you spend 14, 100 on the nitrogen hydrogen ammonia, and you put almost the 93 pounds. Now if you calculate 150 pounds, 93 per almost one dollar. And then you also buy 775 dollar per tons of KCL. So you are both buying it with your own stuff due to the propaganda of this extension and university recommendation. And chloride depressed nitrate when it's ready to take by the plant, what is go? Its leech because chloride is more powerful. They occupy the vehicle, the storage in the plant, and I said go away. And chloride also interferes with carbon carbohydrate production. And then chloride main thing is inhibit notification. Bacteria don't like chloride. Yeah, it good also. And look the data, it's a lot of stuff is you know, and it's significantly decreased if you see the R number there: point seven five significant. So could write, and then you are doing with your own wrong information.

47:40 Now there is US with they say that potassium is a very good thing. It increased quality of everything. And we went and we took out 1400 free trials. We survey and they were only given KCL and 55 seven percent show a benefit effect, and mostly on those soil which was sandy somewhat are compacted. But 55 show a determinant effect. And the effect was that if you have more potassium chloride in the potassium, cadmium is not taken up by the plant. But if become cadmium chloride, it goes pretty fast to this malting barley and potato. And what cadmium that do, it will throb your filter, that is kidney. If you are drinking a barley came out from the and treated with chloride and potato like Idaho, you are getting in trouble. If you are taking all these french fries and potatoes are so very much, it reduce the specific gravity, the denseness, and it's become porous. And when you are doing these oil contact chips and fries, they are loaded because they have a lot of holes. And then also heart problem. And the same is calcium magnesium deficiency in forage grasses. All these people who are in that business, they know it that we get a milk fever and tetany because potassium go fast as compared to calcium and magnesium. And that's why our food is always you know, bone fractured woman hell and all kinds of stuff. Potassium, high potassium creative you are putting. And then human diet low in calcium also not good for your bones, especially in old age. So that is a hope they are saying that it's a quantitative thing? No, no, it's not thanks.

49:30 Now this is very important. When you are applying potassium indiscriminately, like under the recommendation of build-up level, put more, put more, then you are changing your mineralogy. You are changing a very porous which can go back and forth with the water. They have more water holding capacity. They have roots can penetrate, go access to exchangeable potassium. You compact it because potassium is like a nail. They collected, they go back in mineralogy, make it non-swelling. So you'll be always suffering from drought because you nail, you compacted your soil. And also you lose cation exchange capacity more.

50:15 Leaching and water holding capacity so you are changing the quality of your soil. With more care, don't do it. Instead of putting calcium, they would open up your soil.

50:30 Who invented this hoax, which we call it paradox so you can decide after that. There is a paradox and it's really science. This was done across Illinois and 30 or 40 experimental stations for 30, 40 years. And what they found: the data showed a general but now mean close relationship between the increase in yield and the exchangeable potassium content of surface soil. No relation. That was brain, good, good chemist. But I don't know why they didn't take his advice and suddenly in 70, next one a very different recommendation system on the basis of exchangeable pound per pound, very nice. You can get increased with addition of potassium. I, we couldn't get it for all the surveys from all over the world.

51:27 And look at this, it looks like somebody's sitting in air condition taking donuts and coffee and making these recommendation systems. But the consequences are very bad.

51:40 We put for the last from 1940, which we didn't update yet to the other stuff. But look at K input is red and removal is everything come from the soil. And how much useless we put K inputs, which is 66,000 tons per year on average for 40 years. And a current cost of more than 50 million per year. This is just for Illinois. I'm not talking about Iowa, Ohio, Midwest, all over the United States, Canada and then go all over the world. So this is all paid by the poor farmers. Instead of putting them into business, they are destroying them with this.

52:22 With this I will finish and I would be waiting to have a couple of guests. Thank you.

52:36 Well thank you, guys, that's good stuff. All I can say is I'm glad we're not putting any potassium. That's a pretty brutal stuff there. Folks, if you have any questions, please put them in the chat box or the question and answer box. And we'll sure get those over to Richard and Syed. Dale, I'm gonna let you ask the first question or two here.

53:04 The Illinois soil nitrogen test, can you compare and contrast that to the Haney test for nitrogen?

53:17 There are similarities. We're targeting an organic fraction of N, and the Haney test is looking at soil quality and the microbial component. We are too, in a chemical way. The ISMT is simpler than the Haney test. It's easier to run, it's quicker to turn around. And it just makes for an easier approach to very end rates. And that's going to be the main use of it.

53:51 How many universities, how many testing labs, university, private, are using the Illinois soil testing or Illinois nitrogen test? I have to admit I don't know an exact number. I have a couple of, but not. Previously when I came as a student, 30, 40 years, 30 years back, there was 42 tests they were doing soil testing. And now when we invented the annoying test and test, I think one is Smith, one is the written indica.

54:35 So extension did some evaluations of it back some 10, 15 years ago. And those didn't play out so well because they kind of had to have a one-dimensional view of how to interpret the test values. And so it had to be the original calibration with 230 parts per million. They did one study where they had looked at it with sites going from Nebraska over to I think Indiana or Ohio. Well, climate is tremendously variable within that range. And it's going to affect microbial activities. They were also taking samples six inches and then 12 inches and then different 10 years back. So they thought that soil would just stay the same. And another problem was that no attention was given to plant population in some of those studies, and that's critical. It's critical for determining in demand. And that's going to affect the critical level. So if you have a higher population, the critical level shifts upward.

55:50 They were looking for a magic pill, that one simple thing and everything will be solved. No, you have to adjust the populations, the time of sampling, everything. And then they have a lot of went into a lot of.

56:04 Problems, so just to comment as well that the more recent trend with extensions preference is toward biological testing with incubations, that kind of approach will take at least one week and it can go much, much longer than that with aerobic tests. Those are not practical approaches for making an end recommendation. It's just not going to work. It was tried years ago at Iowa State, they dropped it. You need something that's much quicker. And I might add also that we currently have a project where we are going to simplify the test procedure for the ISNT and that should make it even more practical to run routinely.

56:54 Richard, how much does the soil contribution of nitrogen, how much have you seen that change on soils that you would say have better soil health, you know whether they had a cover crop or more diverse rotation or livestock integration? How have you seen that nitrogen contribution change based on better soil health?

57:17 Again, it's not something that we have worked on ourselves. That's a hugely important question and it needs focused research. Different cover crops will have different effects. The use of, for example, cereal rye or annual rye, that's going to be very different from a leguminous cover crop. But no doubt it will affect the ISNT and what the ISMT measures and it will affect how we need to interpret the test results. But we need more data, much more data are needed to address those kinds of questions. Management is a very important crucial part of the soil depleting our soil buildup and particularly when what you put in the grain legumes or just legumes like alfalfa, soya bean, they also differences. Several things that content and no till, cover crops, how deep you go, what type of climate, so there's a lot of variables up there. There has to be included. But yes, if you have under good management putting maneuver rotation, I think nitrogen that pro, that the bile pool is building up, yeah. We have seen the data. I might add a note here that within the last month we had occasion to sample an organic site just north of campus here where we're doing some other work and those ISNT values range from around 250 to 350 in the surface six inches. I mean it looks to me like it's building up and that was not a great soil. It was the same type of soil that Syed mentioned for his father-in-law. The series name is Swigert, yeah, and yet that ISNT was was really up there in the non-responsive range. So they should be able to grow a pretty good crop with no added nitrogen on that.

59:28 We would think so, but again it was that was only a six inch sample. The ISOT came from 12 inch sampling and as you go deeper you'll dilute the test level to go down, so it's a little bit, a little bit comparing apples and oranges.

59:47 Well, we're running short on time here, but Dale, do you have a question or two for Saeed on the potassium bomb that he dropped on us here?

59:57 Yeah, I mean we kind of pointed out the inadequacies of our current potassium soil test, that it only measures exchangeable K, only measures the top six inches. How, I mean we do have soils that are potassium responsive in places at times. How would you design a better potassium test?

1:00:26 Okay, if generally speaking you design a test where you have a static fraction or there, you cannot design tests for potash particularly because exchangeable is constantly coming, non-exchangeable is constantly coming out and any deficiency come only, not reaching, but crop uptake, it's come more and more and it's not like nitrogen or phosphorus. They don't need microbe, they don't need pH, they just need water and the roots that they can take. So if anything is static you can design, but if it's non-static, it's constantly coming out like spring or anything that's coming continuously, you cannot have a test. But the only thing you can do, that if you can go where you have intense leaching you can use a little bit potassium chloride, but possibilities are you will affect your crop quality as well as yield. I would recommend potassium sulfate, but not more than 20 or 30 and they would go.

1:01:33 And put a little bit in the farmer's know this is my good soil, this is my bedside just a line R2. Reduce 20 or 30 or 10 or no, see the difference what you get. Yeah the same is chloride if somebody take risk you can put it with no, no someplace in different part of the field where you know historically you'll go up and down. Just put a two or three a little bit, you know potassium 20 below the level which you are putting for the whole. I would, I would, I would guarantee you if somebody lose I will pay for it. That's what I did with my father-in-law, that if you lose I will pay and he agree and he he increases you but he's not giving me anything.

1:02:22 So don't worry because that's why I show you the data how much potassium is. Yeah so you're saying that if you do need to add a little potassium do potassium sulfate because the chloride is what's doing a lot of the negative effects in the studies that you're showing correct. And that should not be 60 or 80 it should be 10 15 20. That's it. Decide and you can do your own experiment instead of testing because just go a little bit put let those strips. Yeah step trial in your own because if you are a farmer and your hands are really really like not mine because we are all we never go to the field they are soft and any farmer they they work hard they know their field yeah. They can just say hey this is my good soil I get 180 bushel this is my bad soil for whatever reason 90 just put a little bit trial that what you can get from them yeah. After five years four years and then you can testing is just wasting time for potassium particularly unless soil is one to one clay or sandy that you can see how much but two to one which is all united states is mostly a very good soil. I would say don't don't waste your time.

1:03:44 All right Dale you got anything else? I have one final question. I've heard a theory that under no-till cover crops management that increases soil aggregation the size of the soil aggregates that once an aggregate gets bigger than about 10 millimeters in diameter the the oxygen used from the microbes will create a an anaerobic core inside those that provide habitat for free living nitrogen fixing bacteria azobacter azospirillum and that may be contributing to some of these people seeing no response to fertilizer nitrogen. Can you address that?

1:04:43 Yeah that's a that's a great question and it's one that's prompted a current project we have underway looking at I saw that that's why I asked oh how about that. So yes we're excited about that possibility as well and in conjunction with measuring asymbiotic nitrogen fixation we have treatments involving calcitic limestone and gypsum which are hopefully going to help build those aggregates and improve the environment for fixation. I'm really looking forward to checking on what happens with those treatments in the coming years. I would also be interested in mycorrhizal fungi for the glomalin production yeah. Aggregation yes correct. You know if you go out of the box not the extension way out of the box and get see the data then you you will come somewhere a nice place and you will benefit the farmers community and a citizen of this country. Yeah because we are at this point we have given some pre not scientific but this you have to do this.

1:06:00 So it sounds like Dale it sounds like we have a webinar topic for a year or two down the road to have an update on that current project there so that that sounds like it sounds like a good one there so I would tune in Richard and thank you very much for sharing your valuable time and your insights and your research. Really good stuff that we'll have to kind of digest this a little bit. Thank you everyone for joining us and thank you if you're watching this on YouTube. We really appreciate it if you have additional questions you can email us here at Green Cover and we'll get those passed on to Richard and to Syed and try to get any other so thanks again for joining everybody. This is our last webinar of this series. We will likely have some more after the first of the year we haven't quite set that schedule yet but we'll be letting everybody know what that looks like so thanks everybody and have a great rest of the week and merry Christmas coming up. Okay thanks Keith thank you.