The Phosphorus Paradox: Why Your Soil Might Have Enough P Already

0:00 You know, it's more like if you went to Arizona or somewhere really hot and dry. Yeah, and then not so hot. It's not so cold here in winter. We definitely like to get the extremes.

0:21 All right, you ready to go, Noah? Yep, I've just got it live now. The last thing I got to do is get it live on Facebook, and I might even just take care of that here after I get going because I see we're about a minute late, so I'll just go ahead and get us kicked off here.

0:44 Thank you guys for tuning in and sticking with us. We're on week I believe six of our webinar series, maybe even five. But this week we've got a real treat for you. If you guys have ever got our soil health resource guide, you have seen the author who has probably some of the most intriguing articles that we have in there, which is Dr. Christine Jones. So really excited to have her on. If you've not got one of our resource guides, you can request one of those on our website. But I'm going to go ahead and kind of cut to the chase here. What we're going to do is let Christine go for about 45 minutes until about 6:15. She's going to be talking about the phosphorus paradox, and then around 6:15 we're going to answer some of your guys's questions. I've got already several that you guys have emailed in, so try to leave some time for those if you want to type those out in the chat or in the Q&A portion on Zoom. We will get to those towards the end.

1:40 With that, Keith, do you want to go ahead and introduce our speaker?

1:44 Yeah, like Noah said, we're really excited tonight. Dr. Christine Jones is one of our absolute favorite people, one of the top microbiologists in the entire world. She comes to us tonight from Australia where it's well, it's a morning over there, tomorrow morning already. So we're just grateful that she's taking the time to join us. Like Noah said, one of the most popular articles we've ever had in our resource guide is 'Nitrogen the Double-Edged Sword,' where Christine writes very well about nitrogen and how it fits into production systems and a lot of errors that we're making. And now she's going to kind of tackle the other part of that two-headed monster when it comes to synthetic fertilizers, and that's phosphorus. And so I have not heard this talk before. Dr. Jones has promised to write another article for a resource guide on this exact same topic, the phosphorus paradox. So we wanted to give everybody a sneak preview of that, an in-depth dive into phosphorus and really how we can manage our phosphorus and our production systems better.

2:50 Christine, it was great to visit with you yesterday when we were practicing, and look forward to hearing your presentation here this evening.

2:58 Well, thank you very much, Keith, and thank you, Noah. It is indeed a great pleasure to be here with you tonight. I'm so disappointed that I can't be there in person because it's always wonderful to visit with you at Green Cover Seeds and see all the exciting things that you're up to and the great progress that's being made, you know, in the United States with soil health. Yes, speaking to you from down under, it's a beautiful sunny morning here on Wednesday morning. If you ever want to know what's happening tomorrow, just give me a call, as we're one day ahead. But I've only got a short amount of time today to talk about the phosphorus paradox, so I'm going to start with that straight away.

4:12 What we're looking at there is a highly magnified view of a healthy plant root with lots and lots of root hairs and lots of exudates coming out of the roots. So these exudates from the plant are signals for microbes in the rhizosphere and also lots of energy for the microbes in the rhizosphere. So in that situation, what you're looking at there is a relationship between plants and microbes where the plant is feeding the microbes and supporting the microbes and signaling to the microbes for a very good reason. And the reason is that plants can't move. They actually live in the same place for their entire life, whether that's an annual crop that might be there for six months or so, or a prairie grass plant that might be there for 60 years or even a lot longer than 60 years, or one of our long-lived trees that might be there for 600 years. Now you think about it, if you were a seed and wherever you fall that's where you germinate and grow, you know, how are you going to get all of the nutrients that you need? Because if you were just sucking them up out of the soil like a straw would suck water out of a container, then you're very quickly going to deplete all the nutrients that are in the immediate vicinity of your roots. And plants obviously need to get their nutrients in a different way other than just simply sucking them up out of the soil because they would starve. And what we know about plants now is that they actually have an association with microbes that is absolutely essential. It's not just a bonus or not just an add-on that plants and their associated microbes form a single unit called a holobiont. So if you Google that, you'll find lots and lots of fascinating scientific articles about the holobiont concept. So what is a holobiont? What does that actually mean? Well, in simple terms, the holobiont is the host, which is a living thing, which could be a plant or an animal or a person. Every single living thing has a microbiome, and together those things make the whole. And the problem is that we have tended to just think about the host, about the living thing that we can see, the plant or the animal or the person. And in the past, we have actually ignored the microbiome. So if we look at the human holobiont, we have a genetic makeup, our DNA, that we inherit from our parents. And then we obtain our microbiome from our mothers, and our microbiome is absolutely essential for our health. Our genes determine the things we see when we look at another person, you know, how tall are you, what color is...

7:01 Your hair, what color is your skin, what color your eyes, all those kinds of things. But it's actually our microbiome that influences how effectively we function as a living thing.

7:13 So let's look at that collarbone concept in respect of plants. So the plant genes, the DNA, is going to determine what kind of plant is it, what cultivar is it. But it's the microbiome that is actually going to determine its health, and I guess more importantly, or just as importantly from an agricultural perspective, it's the microbiome that's going to determine its productivity.

7:38 This is a very busy diagram and there's lots and lots of information on here. It's a little bit hard to see at first, but this black line across the bottom third of the page there is the soil surface. We have two plants here: on the left hand side a bean plant, and on the right hand side a rice plant. This one's in the fabaceae family and this one's in the poaceae family. We look at all the roots that are underground, and all the little spots all over this diagram are representative of soil microbes.

8:10 So we know there's microbes in the soil, but there are also microbes all over the plant, all over the leaves and the stems and flowers and the seeds. And there are also microbes inside the plant. So we have the rhizosphere microbiome, all the microbes around plant roots. We have the phyllosphere microbiome, which is all the microbes on the leaves and on the stems and the fruits and the flowers. And we have the endosphere.

8:36 You've previously had a talk, or you're about to have a talk—I can't remember, I think you've already had it—with James White. Professor James White was talking about the endosphere, in fact he was talking about the endosphere in the root zone, the rhizosphere endosphere, about how microbes move in and out of plant roots.

9:00 When we have—we can't see all these microbes with the naked eye. So when we look at a plant, we need to understand that they are actually covered in microbes and have lots of microbes in them. In fact, if you were to look under high magnification into a plant root or into a plant leaf, you would see that there are actually more microbial cells in there than there are plant cells. So the plant is more microbe than it is plant.

9:24 And the same for humans. We actually have more microbial cells in us and on us than we have human cells in us and on us. So as microbial populations that live in us and in living plants can determine a lot about the function of that plant, and that's something that we have to always bear in mind: how important the microbiome is.

9:48 So how do you know whether your plant is actually effectively functioning as a holobiont? Does it have a good microbiome? Well, luckily you can get a pretty good idea just by looking at the roots. This little grass seedling here—here is the seed, the seminal roots coming down from the seed, and then the crown roots coming down from on the top of the plant. And all of the roots are covered in root sheaths.

10:14 Some people have asked me recently, well, you know, you're always showing photos of grasses and talking about root sheaths on grasses—do they also occur on other plants? Well, the answer is yes, they definitely do. This is a little broadleaf plant, and you can again see lots and lots of soil sticking to the roots and nice aggregates forming around the roots.

10:36 Just yesterday, as luck would have it, Jesse Frost, who is a no-till organic vegetable producer in Kentucky, sent me this photo of beet with the roots that have all got lovely root sheaths on them. So beet is not even a mycorrhizal plant, and yet it still has good root sheaths. And he has very healthy soil and he says he always sees a root sheath on his beet plants. So it will occur in every plant family, whether they're mycorrhizal or not.

11:06 And if we look inside that root sheath, over here on the left we have the plant root, and over on the right we have some soil particles. And inside that root sheath, this is the microbial hot spot in the soil. This is where the action is happening. And this is where, it's a bit like the human gut microbiome, I suppose. It's what is happening in our gut that is going to determine how well we feel and how productive we can be as a human being.

11:34 And there's a very strong gut-brain connection as well. Like, how well does our brain function? It's going to be determined by the microbial populations in our gut. And the same with plants. It's inside this root sheath where the hot spot is. There are also other things happening, obviously, in other parts of the plant, but this is where it's at.

11:56 And I guess if you think about it, another living thing, say a ruminant, you know like a cow, then the microbial hot spot is going to be in the rumen. And one single drop of rumen fluid contains 10,000 times more microbes than there are humans on the planet.

12:16 And at this level of magnification, all you can see is fungal hyphae in here. So all these little strands that look like cobwebs, they're the hyphae of fungi. There's a whole lot of different kinds of fungi in there. Some of them will be mycorrhizal if it's a mycorrhizal plant. There'll be trichoderma and other beneficial symbionts in there, but there'll also be a lot of saprotrophic fungi that are just feeding on the energy that's coming from this plant. But also they're transporting energy out to colonies of bacteria.

12:46 And it's the more plant roots have been studied, the more recognition there has been given to saprotrophic fungi, which are not necessarily symbionts, but they are definitely beneficial associates for plants. And at this level of magnification, we can't see all the trillions—literally trillions—of bacteria and archaea that are in here. You can see some little droplets of exudates coming out of the plants. This is a very, very fertile, productive environment.

13:16 If our plants don't have root sheaths, then they don't have that environment. They don't have the support of all these microbes. And the other thing is, when you're looking at that and thinking about a root sheath, there is no way that a pathogen, pathogenic fungi, for example.

13:31 Can't access that root because it's completely protected. So we know that 85 to 90 percent of plant nutrient acquisition is microbially mediated—lots and lots of big words there, but basically what that means is that even when we do apply a high analysis synthetic fertilizer, it still has to go through microbial intermediaries. In order, or most of it has to go through microbial intermediaries in order for plants to be able to take it up.

13:58 So today's soils are not actually deficient in minerals such as phosphorus, and we're often told they're deficient in other things like calcium and magnesium and potassium, et cetera. They're actually deficient in plant-dependent microbes. So this is the important thing—they're deficient in the microbes that live around plant roots and form the holobiont. They're deficient in that. So we're only seeing one half of the plant. We're not actually seeing the other half. So these plant-dependent soil microbes actually don't function effectively under most laboratory conditions or glasshouse conditions.

14:34 When you look at, you know, I've spent most of my research career working in a university and I understand firsthand how we used to conduct all of our glasshouse, greenhouse if you like, and laboratory experiments. And they were definitely not conditions that would favor the soil microbiome. So what we see when we're working in research and what a lot of farmers will see when they're using high analysis fertilizers is that you'll see roots that look like this. And for my entire research career, I thought that's what plant roots should have looked like because that's what we always saw. I've seen thousands and thousands and thousands of plant roots that look like that. And when that's all you see, you never think it could be anything different.

15:14 In fact, I remember in the early days when we started to work with biologically active soils and plants started getting riser sheets on their roots, you know, sometimes people would think that there was something wrong with the plant. You know, why is it got hairy roots and why is it got all this soil sticking to the roots? Must have some awful disease. But in actual fact, that's how it should look. And what you're looking at now is not how plant roots should look. That is extremely unhealthy. But we didn't know that.

15:43 And so what happens is that when the plant is only half—it's only the plant half and not the microbial half—it's not really an effective holobiont. It still has some microbes in it but not the full complement of microbes. Then it can't function effectively. And roots that look like that, the only way they can get their nutrients is to suck them up like straws. And that means the nutrients have to be in a water-soluble form. So we have to have water-soluble nitrogen, we have to have water-soluble phosphorus. And otherwise these plants would starve to death because they don't have any microbial bridge. The plant-microbial bridge is not there.

16:23 So because we were in research, we were always looking at plants that had clean roots. We actually came to the wrong conclusions about what plants need. Because in that situation in a glasshouse, if you have plants growing in pots and glasshouses and you add some nitrogen, they will grow more. If you add some phosphorus, they will grow more. So it wasn't a conspiracy, I don't think, to sell fertilizers to farmers. It was what we observed. But we were observing them under the wrong conditions.

16:51 And so this is a very common assumption that's a very deeply held belief now—that if you want to grow anything from flowers in your garden or vegetables in your garden, right through to you know our huge areas of cropland, we all, or most of us who've come from conventional ways of looking at things, believe that plants can't grow or can't grow well unless we add fertilizer. And it's a very, very deeply held belief, and it's still being reinforced by everything we've seen or most things that we see in the literature. It's very hard to change that belief. I remember for myself it was very hard to change that belief because I had spent my years at university believing that plants needed fertilizer in order to grow well.

17:38 But what we know now is that only plants and microbes actually working together can produce fertile, well-structured soil. And it's that soil structure that I want to emphasize there because the problem was that, as most of you listening will be aware, when we used high analysis fertilizer, yes, plants did grow more, but soil deteriorated and deteriorated and deteriorated. And it gets to the point where if the soil isn't functioning anymore in terms of its structure, it doesn't matter how much fertilizer you put on. If the water can't get in there, if it's not aerated enough, and all of the things that we want soil to be, it can't be productive no matter how much fertilizer we put on. And that's probably the situation that we've got to in agriculture today.

18:24 I don't know whether Scott Ravencamp is watching. Scott is a member of the Green Color Seeds team. And we found ourselves in Hungary in November last year, so 12 months ago now, looking at a field that had just been sewn down to a multi-species cover crop. There was four plant families in there, which is the basic really for multi-species—four different plant families. This was the soil. It had been cultivated for hundreds and hundreds and hundreds of years in Hungary. And this is the beautiful effect that the plants were having on that soil—like building soil in a really, really short amount of time. And there hadn't been any high analysis fertilizer placed on that soil.

19:09 So you know, if we want our soil to be like that, we have to think about how we manage it. And what you're looking at there that's giving the soil a structure is of course carbon. And carbon in the soil is linked to nitrogen. So this is just a diagram of all of the atoms of different elements that make up carbon in the soil. So carbon in the soil is about sixty percent carbon, and eight to ten percent nitrogen. And the nitrogen atoms are these little bright blue ones here, and they're linked into these chains. So carbon can't stabilize in soil, it can't give soil its structure unless nitrogen is part.

19:50 Of that molecule but the nitrogen has to be fixed biologically in order for the carbon to be sequestered in a stable form. So if we add the nitrogen from the outside like as nitrogen some form of water-soluble nitrogen, it actually breaks the carbon chains down. So the microbes are going to form a polymer, in other words they're going to join a whole lot of different kinds of atoms of different elements together, and that's a biological function just the same as in our bodies. Our bodies will join a whole lot of different minerals together to form bones for example or teeth or hair or fingernails, and that's a biological process.

20:31 The formation of carbon in soil is a biological process and microbes work together. And there's a whole lot of different kinds of microbes working together to form carbon stable carbon in the soil. And that's another point, is that this is why I think plant diversity is so important, is because microbes work in consortia, in other words they work in teams. They don't work alone. And what we see with biological nitrogen fixing is that the phosphorus solubilizing bacteria actually stimulate biological nitrogen fixing bacteria. I know that sounds a bit complicated, but if we add phosphorus around plant roots, then we're not going to have phosphorus solubilizing bacteria that are stimulated by the plant because we've just given the plant the phosphorus. So it's not going to have all those lovely exudates coming out of the roots. And if it doesn't stimulate phosphorus solubilizing bacteria in order to get its phosphorus, then they're not there, and they are necessary to stimulate biological nitrogen fixing bacteria. And if they're not there, then we're not going to form well-structured soil, which is what we want. We want to have soil that is well structured. So if we add water-soluble phosphorus to soils, we inhibit the entire soil building process. So this is the phosphorus paradox. We believe from what we see in laboratory and glass house experiments that we need to add phosphorus to help plants to grow, but by doing that we are actually having a negative effect on cell structure and soil building.

22:02 Let's just look very very briefly at soil as a carbon sink. This is kind of I'm up on my soapbox about this because Australia was the first country in the world to actually award carbon credits to farmers under a regulated government scheme so where everything is measured and verified according to very high standards. Now we know that soil is by far the largest terrestrial sink for carbon as the world's top soils hold three times as much carbon as the vegetation, so it is the logical place for us to store carbon. And on the 14th of March last year, a world first and an Australian first was when a farmer by the name of Neil Zoltan was actually issued Australian carbon credit units for sequestering soil carbon under our federal government's emission reduction fund. And as I said, this is a highly regulated scheme, and two-thirds of the carbon that Neil sequestered in his soil was calculated to come from root exudates. So the scientists who looked at the data said with the amount of vegetation that he was growing while he was growing above ground, if you worked out if all of that biomass was returned to the soil and transformed into carbon, that he wasn't able to grow enough biomass to actually produce as much carbon as was there. So two-thirds of it came from root exudates.

23:27 And what was the, so this is the photo that I showed initially. These are the guys that are going to stimulate biological activity and soil building in the rhizosphere. Now the important thing about this is that if we add water-soluble phosphorus anywhere near those roots, for a start you won't see that level of exudation. And the other thing is that there's a lot of root hairs on there. You'll notice those roots have a lot of root hairs, and adding phosphorus decreases the amount of root hairs because plant just doesn't need to have the root hairs anymore. We're basically taking away the job and we're taking away that function of the plant as a holobion. Now Neil Zolson has not used nitrogen or phosphorus fertilizer for 20 years, and yet his farm becomes more productive every year. So how has he done that? Well, he's done that by optimizing photosynthesis. So it's not only his soil carbon that's improved but he's got more organic nitrogen. He said his nitrogen levels are going up every year. Well, if his carbon level's going up, obviously his organic nitrogen levels are going up because if they're in the same molecule, his organic phosphorus levels are increasing, but he's not adding any phosphorus. Nutrient cycling is better. He talks about soil structure. His soil structure has improved down to two meters. He says, and plant health. All of these things come back to optimizing photosynthesis. And no surprises here, Niels uses plant diversity. So that's his secret. But he also doesn't mind disturbing his soil. So you'll see that the machine at the back there is called a soil key renovator, which is Nielsen's innovation. And I know that it's regarded as being not the smart thing to disturb soil. But in fact, he, this is a soil key renovator running over some pasture here. His method of establishing a plant community is to actually strip till. And the soil key renovator tills about 17 percent of the soil and only very shallow, you know, like just like a couple of inches. So it's very shallow soil disturbance and only a part of the soil is disturbed. In actual fact, if we went back to 200 years ago in Australia like pre-European times, there were literally millions of small ground foraging mammals here that were not grazers. They didn't eat the grass, but they dug around eating earthworms and beetles and fungal fruiting bodies and all kinds of things that were in the soil. And they caused a lot of soil disturbance. So there was the soil was disturbed to a certain extent. And there's a thing called the intermediate disturbance, an ecological.

26:20 Process or hypothesis if you like called the intermediate disturbance hypothesis that says if you don't disturb an environment at all it's not good for it and if you over disturb it it's not good for it and somewhere in the middle like the Goldilocks principle there is a point where a little bit of disturbance is good and I believe from my own observations that that does apply to soil.

26:42 So let's look in a little bit more detail now about the phosphorus story. The science tells us that when we apply soluble phosphorus to soil only 10 to 15 percent of that which is applied is taken up by plants in the year of application so that means that 80 to 90 percent or even 85 to 90 percent of it is not directly available to plants because it's fixed.

27:15 The thing is that phosphorus is a really reactive element. It's got a negative charge as soon as you apply it to soil it is going to want to bind or to bond with something that has a positive charge like calcium or aluminium or iron or something that has a positive charge. So the reason that it becomes fixed in the soil is because it's bound up with some other kind of element and in soils with a pH less than seven it is going to form compounds with aluminium, and because phosphorus has a negative charge it is going to form a bond with something that has a positive charge like aluminium ion or manganese.

28:21 At pH less than seven, if the pH is seven or above, in other words in an alkaline soil, then applied phosphorus is going to form calcium diphosphate or insoluble calcium triphosphate. In fact all of the things are basically insoluble and not available to plants so as soon as this reactive phosphorus has bound with a positively charged cation in the soil plants cannot obtain it anymore. That means that most of the phosphorus that's in your soil is not in an available form.

28:58 This data is from New Zealand and this depends on the soil test that you use. In New Zealand they use Olson P but at the bottom of your soil test report that you get in New Zealand it will tell you that if your soil has high anion storage capacity, so phosphorus is an anion, so if your soil has a high phosphorus buffering index, then your soil test is only telling you 1.4 percent of the total amount of phosphorus that is there. If your soil has a low iron ion storage capacity, in other words it doesn't buffer it quite as much, it's still only going to tell you three percent of the total phosphorus. In other words you do a soil test and what it's not going to tell you is somewhere between 97 and 98.5 percent of the total phosphorus that's in your soil. Let's just use a figure of 97 percent—97 percent of the phosphorus that's in your soil is not going to show up on the soil test and yet people are using soil tests as a basis for fertilizer recommendations.

30:14 This is basically how it works in a diagrammatic form. Over here on the right you have your soil solution, which is what's called the available phosphorus—this is what is going to show up on a soil test and as I said it's a maximum of three percent. Over on this side there's 97 percent at least either in an organic and inorganic form or an organic form. The inorganic is going to be as I suggested it's going to be bound up with iron or aluminium or calcium or something and then your organic form is going to be what's in your organic matter with your carbon.

30:58 Here we have these different processes. Immobilization is where if you add it as fertilizer it's very rapidly going to move in this direction and be immobilized in the soil. In some of our subtropical soils here in Australia where it's warm and moist phosphorus can be totally bound in the soil within two hours. Applied phosphorus can be totally bound in the soil within two hours—that's in very ideal conditions for it to be mobilized. In some way where it was cold and dry or hot and dry it's going to take a lot longer for that to happen, maybe a couple of months.

31:38 So what we want to have happen in agricultural situations is for this huge pool of phosphorus that we have, we want it to be solubilized and mineralized and move over here to be available but only when plants need it. That's the beauty of what's in the middle here—our soil microbes, our bacteria, archaea, fungi and protozoa, nematodes and macrofauna like earthworms. These are the things that are going to control whether it's going to be immobilized or whether it's going to be mineralized. So this is where we need to work, not with all of our efforts in the past which have been just looking at available P and going 'we haven't got enough, we'll add more.' The philosophy whereas what we need to be saying is okay, so the available P is low, we need to work on here, we need to work on our soil microbes to mineralize it.

32:27 This is some more data from New Zealand. They've done a lot of work on phosphorus and they add massive amounts of phosphorus to soils in New Zealand. So here we have different elements—magnesium, phosphorus, calcium, thorough, potassium, calcium and the pH along here and along the bottom is the month of the year. Remember our months are upside down to you so it starts January, February, whatever, goes through to December. What I mean by our seasons are upside down—we have the same months but different seasons. So the middle of the year down under in the southern hemisphere, June and July is winter and January and December is summertime. So let's just look at this phosphorus—these are available phosphorus levels. This is not the total amount of phosphorus, the total amount of phosphorus in the

33:13 Soil is a straight line. It doesn't vary over the year, but what we're seeing is that in our hotter summer months the availability is very low. In fall when it cools down and there's a little bit more moisture, availability goes up because there's more microbial activity. Then in summer when it gets hotter again, microbial activity goes down, availability of phosphorus goes down. The total amount is still the same. In springtime when it warms up and it's moist, the availability goes up, and then when it gets hot and dry in summer, goes down.

33:44 When is soil testing carried out in New Zealand? All the agronomists go out and collect soil samples here at the end of summer, January and February, is when the soil samples are collected. And farmers are recommended to add phosphorus because they're told that their levels are low. If they just waited till April, which is in the fall, then they would have been significantly higher. So in some ways, this is just a close-up of that.

34:08 When you think about how this varies over the year, you realize these variations are due to microbial activity. And if we want to increase the availability of phosphorus, then we just need to get this increase in microbial activity. So if soil test is not useful for telling you how much available phosphorus you have really in your soil, unless you do a total, Brix readings on your plants will give you a good idea of microbial activity in the soil. And of course a herbic test or a tissue test is going to tell you what is actually in the leaves of your plants. So either a Brix reading or a herbic test will tell you what is being made available, what's moving into the plants through soil microbial activity.

34:53 If we want to increase the availability of phosphorus, remember your total—I've never seen a total that wasn't enough. But we need to make changes to the soil microbiome to enable farmers to actually reduce their inputs because input costs are what, you know, is really the thing that makes it very difficult for a lot of farmers to earn a good income from agriculture. And if we want to restore soil health, and both of those things, obviously, are going to lead to increased profits, which at the end of the day is what you're farming for.

35:25 There are a lot of microbes in soil that are able to solubilize phosphorus. There are fungi that produce phosphatase enzymes. There are a lot of bacteria that produce phosphatase enzyme. So this is the enzyme that actually makes the fixed phosphorus available to plants. Now I said at the beginning of this webinar that when we add a highly reactive element like phosphorus to soil in a water-soluble form, it is very quickly, because it's a negatively charged ion, it is going to look for some positively charged cations to bind with. And once it binds, it's no longer available for plants. And plants, some plants can produce organic acids that can break those bonds. But even if they do, they can only break the bonds in the phosphorus that's very close to their roots.

36:19 So we need microbes that are able to produce phosphatase, the enzyme that actually breaks that bond between the phosphorus and the other elements. And then we need microbes that can transport that back. Other kinds of—we actually want an intact, fully functioning soil microbiome with lots and lots of different kinds of microbes. Some of them are going to be making elements available, and some of them are going to be transporting them.

36:43 How are we going to support these microbes in the soil? Well, plant diversity. Obviously, every different kind of plant has different rhizospheres, supports a different microbiome. We know now that if we have four functional groups, or four plant families, if you like, as a minimum, the plants' microbiomes will cooperate with each other. If all of the microbiomes are the same, then they compete with each other. So the microbiome, the microbes that are living around plant roots, can detect using chemical signals what other kinds of plants are growing close to them and what other kinds of microbes are close to them. And if the microbiome detects that all of the plants around it are the same as itself, then it is going to compete with them. If the microbiome detects that neighboring microbiomes are different, they will cooperate. And especially in situations like nutrient deficiencies or moisture stress or anything like that, wherever the plants are under stress, when the microbiomes are different, the research shows that they will cooperate.

37:55 Plant diversity is very, very important for stimulating that. And also if you have livestock, strategic grazing is important because photosynthesis is important. We don't want to graze everything that's above ground. We don't want to remove all of the solar panels. And we need to replace our high-analysis fertilizers with biology-friendly fertilizers. So if soils are healthy, you will not obtain a response to added P. That's another good sign that you have healthy soil.

38:28 We have farmers here in Australia have experimented with—they've been using biostimulants in place of high-analysis fertilizers. And then they get a bit curious and they go, what would happen if we put out some monoammonium phosphate or diammonium phosphate or something, and I'll just put a strip of that through there, through their wheat field? And then it'll just show up on the yield monitor just as a straight line with lower yield. So where they have actually added water-soluble phosphorus in a biologically active soil, it reduces plant yield.

38:59 If you've applied phosphorus for the last 10 years and you've only used 10 percent of it, you now have enough for the next 90 years plus what was already in your soil to start with. A lot of people have this fear that they don't have enough phosphorus or they're going to run out of phosphorus. Australia has the oldest, most deeply weathered soils of any country in the world, because we didn't have any recent glaciation like you had in North America, and we didn't have any volcanic activity or anything like that that is going to produce relatively young, new, healthy soils. Our stores are very old and deeply weathered, so our phosphorus levels on an available test might be, you know, one part.

39:50 Incredibly low, and yet we've now got farmers doing things to increase the microbial activity in their soils that their tissue tests or their leaf tests are showing absolutely spot on optimal levels of phosphorus in their plants. If they have been applying phosphorus in the past because that's what they've been told to do, then most of them have a huge phosphorus bank just from what's been applied irrespective of what was in the soil.

40:23 So which future will we choose, irrespective of whether we're in Australia or New Zealand or Europe or the United States? Every single farmer can make a choice about which way they want to go with their fertilizer programs. They could continue using high analysis fertilizers, which is going to produce high input costs. There's a very interesting program that's been started in Ireland, it was started back in 2012, called the Smart Grass program. This is for grazing for livestock producers, but they were looking for a way of getting away from using nitrogen because the input cost was so high for farmers—not only the cost of the nitrogen but also all of the pests and disease problems and animal health problems and everything that went with that. They've now morphed into the Smart Sport project because they've realized it's actually not about grass, it's about the herbs, and they're looking at very diverse pastures. It's cutting input costs hugely.

41:27 I know that's not a row cropping situation, it's a grazing situation, but moving away from high analysis fertilizers is being shown around the world in cropping situations as well to drastically reduce your input costs. You're going to have deteriorating soil function if you use high analysis fertilizers, that's just a given, and it's going to have negative environmental outcomes that the rest of society are not going to be very happy with. So we can continue with business as usual or we can look at a more regenerative form of agriculture where we're going to replace high analysis fertilizers with plant diversity and biostimulants, and then we will see improved soil function as everybody is reporting all around the world. Our input costs will be reduced, we'll have increased plant, animal, human, and community health—even for the people living in the cities in the urban areas—and we'll have sequestration of soil carbon, which is going to underpin really everything else that happens in our soil. If our soils are moving forward, then stored carbon is going to be increasing, and increases in soil carbon is going to improve nutrient cycling, it's going to improve soil structure, it's going to improve water holding capacity, it's going to improve nutrient density in the food, and it's going to underpin everything else that happens. As we've seen time and time again, if we're using high analysis fertilizers, one of the biggest impacts that we're actually having is on soil structure. The reason it's having an impact on soil structure is because we've taken away the job of the plant in stimulating the microbes around its roots, and our plants are no longer functioning as a holobiont. They're just trying to function on their own without any help from soil microbes, and it's a very stressful situation for plants and it's not very good for productivity.

43:21 So that's it in my 45 minutes, I think I've done it in with one minute to spare. I hope you're impressed. So I'm ready for questions. That's the end of my slides.

43:38 Wonderful. Well, I was going to butt in there but I decided not to and tell you that aluminum makes you sound even smarter than you already are in the United States.

43:51 Aluminum it is. You guys just can't spell. And even you say it—I can never remember what is it, aluminum? Can you say it? Aluminum, that's how I say it.

44:05 Oh, there you go. I can't even get it right. Aluminum, yeah, I forget every time, and I forget about inches and acres.

44:12 I did type the American translation into the chat box too. Aluminum, thank you Keith. I'll have to practice that for next time.

44:22 Well, yeah, we definitely have quite a few questions here, but I definitely want to take a second just to thank you. That was a lot to take in, and for those who maybe are watching this and weren't taking notes fast enough, we do have this recorded, and so we'll have that recording available for you guys as well. So with that, let's dive straight into the questions here. I did get a question in an email and you kind of touched on this a little bit, but talking about organic phosphorus—is organic phosphorus applied through manure more available and efficient to plants than mineral fertilizer? And obviously, kind of based on your talk, it sounds like there might not need to be as much applied to the soil, but do you want to touch on that for a second?

45:09 Thanks for that question, Noah. Again, that's going to depend on if the manure is what we call raw. I don't know whether you use that word in other words, if it hasn't been composted. If you're adding raw manure to soil, it actually creates an imbalance—a lot of imbalances actually. It causes an imbalance in terms of the kinds of bacteria that are going to be in the soil. In other words, they're not going to be the plant associated microbes. It's going to be microbes that are going to be there trying to use up that raw manure, so it actually changes the soil balance in a detrimental kind of way, and it tends to throw a lot of other things out of balance. So what we really want to do is to have these—we want plant dependent microbes. So photosynthesis is the way that we want to channel energy to the soil to stimulate the plant associated microbes. They can do everything that we want soil to do because that's the natural way, that's how it functioned in the prairies, and that's what we have to try and recreate. In some ways, just adding raw manure to soil is, as you say, it's just a bit like just using fertilizer really. You know, we're thinking that we have to add something. If the manure has been composted, then it's going to.

52:57 Of biological activity in the soil. I just remember asking the lab manager about that. I said this is crazy, this is supposed to be the total amount of phosphorus that's in this soil, and it's going up every year. And he says yes, because all it is is a nitric acid extraction and that's not what microbes use. Microbes use phosphatase enzyme. So even a total phosphorus measurement in the lab is not really telling you the total amount, but it's a much much better guide than the available because remember your available phosphorus is somewhere between one and a half and three percent of what's actually there.

53:29 Are there any tests that are more accurate as far as getting the total amount of phosphorus? Well, you could use an assay like an x-ray diffraction method or something as a geologist would use. If a geologist was looking for minerals they might be looking for something that's only there in trace, you know like gold or something like that. So they're going to actually use a method like x-ray diffraction that tells them absolutely everything that's in the soil. So you could find out absolutely everything that's in the soil, but I just realized I didn't actually answer the first question. The first question was the amount of phosphorus that's going out the gate in your produce, whether it be grain or whether it be milk or meat or water, it might be, is a tiny tiny amount of the total amount that's in your soil, and it is going to be it's just a matter of increasing the amount availability of what's there. You will have enough as I said for thousands of years, and it's a matter of stimulating the microbes and stimulating the plants and the soil microbiome to make that available as plants need it.

54:33 I mean that's the other thing. You don't need it to be available all the time. You only need it to be available when plants are going to use it. And one of the issues, to go back to a previous question about using things like manure, is that plants can't possibly take up all of the phosphorus that's in there. And if you get, if it's just surface applied and you get heavy rain, obviously it's going to end up in the waterways, which is the issue that we have, not only manure but also other phosphorus fertilizers. The surface supply. And if we have any soil movement at all, in other words if the water has any sediment in it, like if it's muddy water, it's going to be carrying phosphorus with it too because the phosphorus is going to be attached to those soil particles and it's going to end up, you know, in your lakes or in the ocean, you know, like Chesapeake Bay or Lake Erie, all those kinds of things. You know, raw manure will do that just the same as phosphorus fertilizer will do that.

55:24 On the topic of those tests, Mike McDonald's asks, does the Haney test gauge the available phosphorus in a way that meets your expectations? Yeah, I can't comment on that, sorry. No, I don't know enough about the Haney test. Yeah, no, that's fine to be able to comment on that.

55:40 Can you speak about Brix test a little bit? In my experience it's very hard to get readings from plant leaves rather than the fruit. How do you get a reliable and easy Brix readings from non-fruit plants? Well, some people have, you know, the Brix is going to depend on how much you macerate or what's another word for that, like how much you grind up the plant material. Obviously if you just get some leaves and roll them around in your hand and push them into a garlic press, it's pretty hard to get sap out of them. So some people will have taken to using a kind of like a grinder, you know, like a little coffee grinder or something like that to grind them up. You just have to be aware of the fact that if you do grind the leaves up that you're going to get a much higher Brix level. So provided you use the same method every time, what you're doing with Brix is actually comparing. If you wanted to compare different treatments, for example if you wanted to compare where you'd used a biostimulant compared to where you'd used a high analysis phosphorus fertilizer, and you're going to use Brix as a like Brix is really good for doing those kinds of comparisons rather than, you know, measuring at different times of the year or different places, is going to give you data that's very hard to pull together into some kind of a picture. But if you have a field where you've got different treatments then you want to see what the effect of the treatment is on the uptake of nutrients from the soil, Brix is a really good indicator of that. And if you can't, if the leaves are too mature for you to be able to get sap out of them, you can grind them up but you just have to be aware of the fact that that's going to raise the Brix. And provided you do that to all of the samples then it's fine because you're still just using it for comparison because actually what you're doing with Brix is looking at dissolved particles of sand in there as well. So you're just going to raise it but you can still use it to differentiate between treatments.

57:46 Okay, this is probably my favorite question. Is there a scientific significance to your fondness for fuchsia? Omnisphere, I think it's in regard to all the beautiful colors behind you. Oh, I can't see them, maybe it looks different on your screen to mine. I'm actually sitting in front of a white wall, so I don't know. That was more of a humorous comment I think from Brad Zimmerman.

58:22 Says this is the opposite of what we have been taught. Why is this not common practice among growers? Because all of the experiments that we can probably throw out, just about all the data that comes out of universities or research stations where we haven't had biologically active soil. So from my own experience working as a research agronomist at a university for most of my career, we would go out and collect soil and put it into big bunkers and it would sit there for probably twelve months or two years sometimes because we'd be putting soil at one end of the bunker and taking soil from the other end, and the soil that we were using hadn't had plants in it for a really long time.

59:09 So it didn't have any microbially dependent plant dependent microbes in it. And then we would homogenize it. We would take a certain amount of soil and homogenize it through a machine called arroyo. Because if you're going to have 200 pots in an experiment for example, you want them all to have pretty much the same kind of soil in it because you want to know whatever treatment you apply, is this going to have an effect or not? So you don't want to have some pots with salt soil that's different to the others. So the soil is all homogenized and put in those 200 pots. It hasn't had plants growing in it for a really long time. And then we put plants in it and apply, say for example, different amounts of phosphorus. And the ones that we apply more phosphorus to, to a point, are going to grow better because the plant is not functioning as a hollow violent in that situation.

59:58 We need to have biologically active soils where plants are able to form a hollow ion because a lot of the microbes that form that association with plant roots are going to come from the soil. So if our soils are basically dead because we've used so many chemicals on them, we've kept them there for so long, this is why cover crops are just so incredibly important to actually keep the soil alive. So in a cover crop situation where you're growing a crop and then a cover crop and then a crop and a cover crop, and keeping the plant dependent microbes alive in the soil, or at least if they're in a dormant state, that can open up in the soil, it's a totally different situation to in a research institution that is using soil that has been stored for a really long time.

1:00:46 I mean, you think about it: when you're doing research at a university, where does the soil come from? Has anybody ever thought about that? It comes from a big pile of soil that hasn't had plants growing in it for a really long time, and oftentimes it's going to be sterilized as well. So it's homogenized, sterilized, doesn't have good levels of biological activity. And then when we add something like water soluble nitrogen or water soluble phosphorus, it makes plants grow. But in situ, if you went out, if you could find a really healthy area of prairie, if there is any such thing still existing, which I doubt, and you were to add some water-soluble nitrogen to it or some water-soluble phosphorus to it, you actually would not see a response because the plants don't need that because they've got their own mechanism.

1:01:34 I mean, when you think about it, think how beautiful the prairie soils were. We had plant diversity there. We had plants all year round there. We had really, really active soils and the soil microbiome was functioning. It would sort of be like if you took a cow—let me use another example. If you took the rumen out of the cow, it just couldn't possibly function because cows or any rumen in it for that matter, any mammal, even, cannot digest cellulose. The only thing that can digest cellulose is microbes. So microbes in the rumen are using an enzyme called cellulase that breaks cellulose down. So the cow ingests all that, the grasses—let's say it's out there grazing on grass—and ingests that material, and the microbes in the rumen break that material down and turn it into a form that the animal can use. And the animal is also going to have an intake of some of those microbes themselves.

1:02:31 So if we took the rumen away from a cow, the cow couldn't function. When we take the microbiome away from a plant, the plant can't function. So in our laboratory situations and in our glass house or greenhouse situations, we've mostly been looking at plants that did not have an effective microbiome. And so we can throw most of the textbooks out because they talk about plants taking nitrogen up in a water-soluble form, in an inorganic form. When they talk about plants taking phosphorus up in an inorganic form, and that's not actually how it would work in a biologically active soil.

1:03:06 And it wasn't anybody trying to do it to make money out of selling fertilizers to farmers, although that happened. But I mean, I was an agronomy researcher myself. I wasn't trying to do something that would be detrimental for farmers. We honestly just didn't know. I didn't know. I thought plant roots were supposed to be white and clean. And if they had little black marks or brown marks on them or something, you know, they were diseased. And they had some kind of a root rot, you know, like a pathogenic fungi or something that was attacking the roots and causing those brown lesions, all those black lesions on roots. Was because they didn't have a riser sheath. They didn't have the protective coating of microbes and soil around them that would actually prevent pathogenic fungi from attacking them.

1:03:57 So the unfortunate thing is that when we haven't had a plant with a complete microbiome and it hasn't had that protection around the roots, we've not only used fertilizers to try and get it to grow, but then we've also put fungicides on seeds and we've used insecticides because everything is going to want to attack that plant because it can't defend itself.

1:04:22 Okay, I know that we're past time here, so I don't want to take too much of your time. But if you do have just a couple minutes, there are a few questions on biostimulants if you want to touch on that for a second as far as some examples of biostimulants and what you would recommend.

1:04:40 Yeah, okay, no, and that's another great question. I mean, some people are in a situation where a monoculture is really all they can get their heads around, you know? I mean, I think in the future we're going to see a lot more intercropping and all that sort of thing. But for us in Australia, where most of our crop production is cereals like wheat, yes there are some farmers experimenting with intercropping in wheat, but a lot of people can't get their heads around that. So they've moved away from using high analysis fertilizers, using a biostimulant, and putting a biostimulant on the seed. By a biostimulant, I mean I don't mean anything that's got nitrogen in it or anything that's got phosphorus in it. I mean something that is just going to.

1:05:23 Stimulate the relationship between the plant and the micro probes in the soil and we find that something like a compost extract, a fermented compost extract or a vermi liquid, like a worm leak shade or fermented seaweed product or something like that at really low concentrations. That's the important thing, really, really low concentrations. Will actually stimulate the relationship between the germinating seed and the microbes in the soil and form an effective microbiome. You will see those riser sheaths formation around your seeds and then you can also come back with a like a foliar application in the early ceiling stages where plants are just emerging.

1:06:05 The plant intelligence and the microbial intelligence, if you like, once the plants actually form that connection with microbes and start communicating with them, sending exudates down to the soil microbes, start accessing all the elements that plants need to grow and also it will bring water to plants as well. Mycorrhizal fungi, most important thing that mycorrhizae bring to plants is actually water. Because it's important for the microbiome to have a healthy plant because the plant is feeding the microbiome. You're necessarily working together. It's a relationship that works for both parties.

1:06:37 The most effective bias stimulants in my experience are the simplest ones because all you want to do is recreate something that would happen naturally in the prairie soil. So if you think about a prairie soil in its natural state, you would have some organic matter breaking down in there. And then when it rains, it's going to take some dissolved organic carbon out of that. So you're going to have some like a very, very, very dilute form of a compost extract. And you're also going to have things like earthworms moving around in there that are going to produce the same sort of products as what you get from a vermi liquid or something, again at very low concentrations.

1:07:13 Any of the work that's been done on the concentration effect has shown if you put too much of those things on, it can actually have a negative effect because you have to remember that in a natural environment, those signals are going to be present at very low concentrations. As in the human body, all of the hormones that work in the human body are extremely low concentrations and they have the opposite effect if they're at a high concentration. Something like adrenaline, for example, is in parts per trillion, and that's going to be the hormone that is going to get you out of danger. You know, there's a runaway bus or something, you have to jump out of the way. A very small amount of adrenaline is going to trigger a response in your body in less than a second. Like it's a fraction of a second that you're going to respond to that to a danger that suddenly appears.

1:07:58 But if you were given an injection of a high rate of adrenaline, you'd be totally immobilized. You would be incapable of moving at all. So a high concentration of that same hormone is going to have completely the opposite effect. And people sometimes think if a little bit of compost extract is good or a little bit of vermi liquid is good or something, or we'll put twice as much on, but in actual fact it has to be very dilute because biological signals work at extremely low concentrations.

1:08:22 It's important not to put any nitrogen or phosphorus on with those seeds unless you're in a transition place. Like if you've been using lots of nitrogen and you don't have free living nitrogen fixing bacteria in the soil, then you will have to wind off nitrogen over a three year period. I will say that with phosphorus you can go cold turkey and just cut that out completely. With nitrogen you do have to cut back slightly.

1:08:44 David Johnston, for example, has been doing some experiments with corn that had UAN. I can't remember how many pounds per acre, I'll just pick on a number like 250 pounds per acre or something of UAN. And he found that with using a compost extract from his Johnson Sioux bioreactor, they were able to get they only used 15 percent of the UAN and got equivalent yield and made something like 290 dollars per acre more profit because of the reduction in the input costs. And that was in the first year. This is going to be a five year experiment. I reckon that by the third year they won't have to use any UAN at all.

1:09:27 So you probably can't cut back completely in the first year, but you can over a three-year period you can wind back on your water soluble. I know I'm talking about nitrogen now, but with phosphorus, but let's just finish the nitrogen story. You have to wind off, you have to back off nitrogen slowly, and you will fall over a cliff if you just cut it out if you haven't got plant diversity because the problem is in the monoculture you just don't have your nitrogen-fixing bacteria there. With phosphorus you can cut it out immediately and go to a biostimulant on the seed, preferably.

1:10:03 The best system of all is a biostimulant on the seed and in furrow and then as a foliar spray as a follow-up. You know, when plants are got five or six leaves or something at that early stage. And measuring risk levels, looking at digging out plants, looking at the riser sheets and the other thing too, doing herbage tests.

1:10:26 And if for some reason, and obviously you know our soils are incredibly dysfunctional around the world. You know, we've got because of 70 years of going down this chemical path, we have dysfunctional soils. We can't expect them to just suddenly be perfect you know tomorrow because okay we're going to start using high nails to fertilize, we're going to use a biostimulant. We're going to have perfect soils. No, you're not. You know your patient is in intensive care at the moment. They're not going to be able to get up and run a marathon. So it's going to be a slow process.

1:10:53 Don't forget to keep doing leaf tests and if they need something, apply it as a foliar. So even if they need nitrogen, apply it as a foliar because it's going to do much, much less damage. Those elements that can't be taken up very well as a foliar, but you'll be able to find out what they are. So most things can be applied as a foliar if needed.

1:11:33 So don't deprive your plants of the things that they need. And what you'll find is that over time they'll need less and less things to be applied as follows.

1:11:44 Well with that I think we'll conclude. Thank you so much for your time, Dr. Christine. We really appreciate it. I know I learned a lot and obviously just based on the amount of questions there's a ton of interest on this topic. And I think you are maybe bringing up some things that shouldn't be controversial but like you said it is a mind shift on how we've been doing things. So I think that's good and challenging and a lot to soak in. Yeah, we just really appreciate the fact that you were on with us this evening.

1:12:15 I'm sorry for those that I did not get to the questions. You can email those to me if you would like and I can maybe pass those on to Dr. Christine. My email is just noah—n-o-a-h—greencoverseed.com. And next week we will be back on at 5:30 with Rick Clark and Dan de Sutter. We're going to be talking about kind of the holy grail of organic no-till. Excited to have those guys on with Keith as well. And with that, is there any closing thoughts that you have for us?

1:12:46 Dr. Jones: Well, no, not that wouldn't take me about an hour to tell you, Noah. Other than to say thank you very much for this opportunity. And I understand that it is hard to get, you know, our head around thinking about the soil, the way that it functions in conjunction with plants. And it took me a long time from my own conventional training. It took me a long time to actually get my head around the fact that you can grow things without adding fertilizer. And when you think about how it works in natural systems, and I think the biggest question that's always come up in production agriculture is 'yes, but all whereas that doesn't happen on the prairie.' It's all very well for you to talk about nutrient cycling on the prairie, but you're not exporting phosphorus and calcium and magnesium and everything out the gate. But if you actually look at what is in the soil in total, you'll find that there are enough minerals there in soil to actually last for thousands of years.

1:13:55 Phosphorus is definitely one of those deficiencies, but even that is rare. Phosphorus is not something that you're going to be short of, but it's a matter of activating it. You have to make it available. And it is plant-dependent microbes that are going to make that phosphorus available, because that's how it works in nature. So we don't even have to add the microbes. We just have to stimulate photosynthesis. And we stimulate photosynthesis by, well, plant diversity is the best for photosynthesis, but also a biostimulant that is just a very low concentration of something very natural that would occur in the soil anyway will stimulate that relationship between plants and microbes.

1:14:42 So I think the essential thing is it's not just any microbes, it's plant-dependent microbes. And the fact that they're plant-dependent means that 99.9 percent of them can't be cultured in the laboratory. So we can't even build up the numbers of these things. You know, they're what we call non-culturable microbes. Most nitrogen fixers are non-culturable. Most phosphorus solubilizers are non-culturable. So you can't—we try to complicate everything all the time with the things that we add. You know, we always want to make it complex. It is a complex system, but it has some very simple triggers in there. And there are some very simple things that we can do. And we've got farmers around the world demonstrating that. I mean, Ian and Diane Hagerty didn't own any land to start with. They ran a service station, what you might call a gas station, I guess. I'm doing enough money to buy a very small farm—their home block. And now they're farming 40,000 hectares, which is I don't know about 100,000 acres or something. And they don't use any nitrogen fertilizer. They don't use any phosphorus fertilizer. They use a biostimulant, which is a very simple worm leachate or vermi liquid and a compost extract on their seeds in furrow as a foliar. And they out-yield their neighbors. And they have such high quality in their wheat that it's the highest quality wheat grown in Western Australia. So, you know, I mean there's plenty of evidence out there. But it's a big leap of faith. I understand that it's a big leap of faith. And again, we have these really deeply held beliefs about things. They're very hard to change.

1:16:27 It's just a function of human psychology for all of us. It's very hard to change deeply held beliefs. And one of the deeply held beliefs that we have, that's in every textbook that you pick up, every article that you read, everything that students are taught at universities, is that plants can't grow unless we add nitrogen and phosphorus to them. And yeah, that's just not the case. But yes, certainly they will grow in a dysfunctional soil. That is true. And in fact, in a dysfunctional soil, that is true. They won't grow unless we add nitrogen and phosphorus to them. So what we have is to get a new perspective and look at it a different way. What can we do to increase soil function? And we find that if we actually have functional soils, we don't need those additives or any of them. We won't need the fungicides and insecticides either if we have functional soils. Let's go look in the preparatory. You know, what do fungal pathogens do? You see there, don't you? Do you see any nitrogen-deficient plants there? No, you don't. You'll only ever see nitrogen-deficient plants and phosphorus-deficient plants in a farmer's field. That's the only place you're ever going to find them. They're not out there in nature. So, you know, how do plants cope in nature?

1:17:48 Sorry, that wasn't exactly a short conclusion, was it? I knew that if you give me time to get on my soapbox I will.

1:17:58 Give me the opportunity, I mean, I was just going to make a comment that you have a great challenge in front of you to summarize that entire talk down to about 1200 words that we can put in our soil health resource guide. So good luck with that.

1:18:19 I have it in writing from you that I was going to send you 10,000 words and you were going to summarize them into 1200. Remember? You said I'm a very good editor. You said I don't think I can do this. I said, you said don't worry, send me.

1:18:36 Yeah, that is true. Thank you so much.

1:18:47 Very good. Well, thank you. Thanks again. Thanks for the great questions. And again, yeah, thanks for the opportunity. And yeah, all right, so I'll say goodbye. Leave you goodbye everybody. Yep.

1:19:04 All right, we will see you guys all next week. Thanks, Keith.