The Phosphorus Paradox: Why Your Soil Has Plenty (But Plants Can't Access It)

0:00 We're going to give her a chance at it. Keith, do you want to go ahead and introduce Dr. Christine Jones?

0:07 Yeah, certainly. Dr. Jones, I'm sure, is not a stranger to the majority of the people that will be logging on here. One of the world's preeminent soil microbiologists. And like I said last week, one of the things I really appreciate about Christine is just her ability to take this really scientific high-level information and share it with folks like me, folks like Noah, you know, farmers who maybe don't understand all of the science or scientific terms, but she can really bring it down to the farmer level, which is great because it doesn't matter what kind of information you present if the audience can't understand it and can't apply it, it really isn't that helpful. So Christine is really good about getting it down into farmer language so that we can understand it and that we can apply it.

0:58 So the phosphorus paradox, Christine, correct me if I'm wrong but when you did this back last fall that was the first time you'd really kind of done this particular talk. Is that correct?

1:07 That is correct.

1:09 Yeah. And it had a tremendous amount of response and so we're really excited about you doing it again. There was a lot of questions last time and I'm sure we'll have an extended question period again. But you know this is such an important topic because nitrogen is all over the atmosphere. We're never going to run out of nitrogen because it's so much in the atmosphere but phosphorus is definitely a limited resource. The mined phosphorus is getting more and more expensive and getting more and more scarce. So I'm really excited about your talk because you're going to talk about how to unleash the phosphorus that we already own, the phosphorus that's in my soil, and that's exciting to me because that can save me a lot of money.

1:53 So, I am going to turn it over to you. I'm going to hide my video and mute myself and I will listen along with everybody else. So, take it away, Dr. Jones.

2:03 Well, thank you very much, Keith. And thank you for that wonderful introduction. I'm not really sure that it's well deserved because the reason that I've agreed to repeat this webinar is because some of the emails that I received after the last one indicated to me that a lot of people actually hadn't understood what I said last time. So I received quite a few emails along the lines of, well if you think conventional phosphorous fertilizers aren't a great idea, which phosphorous fertilizers would you recommend that we use instead? Now, I'm not laughing at the people who've sent those emails. If you're one of the people that emailed me saying 'Which phosphorous fertilizer should I use?' what that indicates to me is that I didn't explain it very well last time. So I'm going to have another go at explaining it, and hopefully it will be a little bit clearer.

3:00 Now the issue with talking about phosphorus is really I need to talk about how it's really all about how soil functions because phosphorus is actually, believe it or not, an abundant mineral in your soils but it is one of the least if not the least available and it is one of the least if not the least mobile. In other words, it doesn't move very far. Even when you put phosphorus fertilizer on your soil, it pretty much stays exactly where you've put it. And the phosphorus that is already in your soil pretty much stays exactly where it is. And it is not in a form that's available to plants. So we talk about it being a very limited resource. If we look at soils and we look at the total amount of phosphorus in soils, it is an abundant resource in most soils. And so we have to figure out how to make that available.

4:00 So if I can operate the technology here and do a, I'll see if I can get this better than I did it last time. Share screen.

4:10 Guess what folks?

4:14 I was just going to say it's not letting me.

4:18 It's not going to let me do this. I thought I had this down path.

4:24 It's starting. We can see your slides now.

4:27 Oh, that's a good start, Keith. Thank you very much. Can you see that one?

4:33 So everybody has to cross their fingers and toes.

4:39 You're good. You're good. And we're all going to pray that the internet doesn't go down for the next hour and a half and also that I can manage to switch from one slide to another without, yeah, right. The phosphorus paradox.

4:54 Now the first slide that's shown there I will show this one again later in this presentation but what you're looking at is a highly magnified view of a very young root from a plant with lots of root hairs and you can see there are lots of exudates coming out of that plant root. Now that is a very healthy situation. That plant is going to be, if it was in the soil, would be surrounded by microbes that would be responding to signals that are coming from that plant because the plant is feeding the microbes for a reason. It's feeding them in exchange for nutrients, but it's also feeding them in exchange for genetic material that the plant might need for some reason or other. And we'll talk more about that probably next week and the week after I'll particularly talk about plants taking genetic material from the soil. So the plant has this ongoing conversation with microbes in the soil and the microbes also have an ongoing conversation with the plant.

6:00 And really this is the basis of the whole story about phosphorus, the whole story about nitrogen and the story about all of the other macro and micronutrients that plants need. It is all about what is going on around plant roots. And that is something that we as farmers, as ranchers, we can change what happens around plant roots. We have the power to change that. So we have the power to change what happens in our soil.

6:32 Now, somehow or another, I just accidentally, you're not praying enough everybody because I've just jumped over two slides.

6:44 Okay, so plants cannot move. I mean, that's obvious. We all know that, but we don't think about what are the implications of the fact that plants cannot move. And if you think of a plant and the roots going down into the soil, the roots can only be in that one spot wherever it is that they are. And I just said that phosphorus is not mobile. So if phosphorus is an inch or 2 inches or 6 inches away from plant roots, there is no way that they can get it even though there might be abundant phosphorus in the soil. And it doesn't matter whether a plant is just going to be there for 3 months or 6 months or 6 years or 60 years or some of our long-lived plants for 600 years. In fact, the longer a plant lives in one place, the more difficult it is actually going to be for it to get everything that it needs. And you know, if a plant is going to be in one place for any amount of time really, it's very quickly going to use up everything that's in the immediate root zone. So that's something that I want you to remember: that there has to be another mechanism other than plants simply sucking up nutrients through a straw, as we're commonly led to believe, and which is why nutrients are commonly applied in a water-soluble form. We have this sort of hypothesis in our head that okay, so if the soil is moist and if the nutrients are water-soluble, the plant is going to be taking up moisture and at the same time as it's taking up moisture it's going to take up all the things that it needs. Well, it doesn't actually work like that because if plants could only access the nutrients in the immediate vicinity of

8:26 The roots as I said they would very quickly starve.

8:29 So what is a holion? This is a concept that I introduced last time I gave this webinar and a holion is really the whole. It's the plant and its microbiome because it cannot function without the microbes around its roots. So there are every living thing is a holion. Humans are holiants as well because we cannot function without the microbes in our gut. Ruminants are holiants because they cannot function without all the microbes in the rumen. And I gave the example last time of a cow. If we took the rumen away from a cow, there is no way that the cow can possibly survive. When we take the microbiome, in other words, the microbes that are living all around the roots of a plant, when we take that away from a plant, there is no way that the plant can survive unless we force feed it. And that is what has actually happened in our current day agriculture is that the sorts of things that we've unknowingly done like having bare ground between crops by even having a large amount of bare ground between rows. If you think of something like corn with widely spaced rows and a lot of bare ground between those rows or having something that grows for a couple of months of the year and then the rest of the year the ground is bare.

9:52 We have created conditions where the microbes fail to survive in the soil. So it's very hard for plants to actually have an effectively functioning microbiome. But it needs a microbiome to work as a whole. So in our case in the human holiant and this is another important distinction as well also works for plants that we have genetic material our DNA that we inherit from our parents and so our hair color and our eye color and those kinds of things are inherited from our parents but we obtain our microbiome from our mothers and it is actually our microbiome that is essential potential for our health. So in the case of a plant holion, the plants obtain genetic material from their parents. I suppose it's the same situation. So we know that a wheat plant is going to give rise to wheat and a corn plant is going to give rise to corn. I mean everybody understands that. But it's the plant's microbiome that actually determines how healthy and productive that plant is. And the microbiome is also passed on from one plant to the next generation through the seed. So the seed will have the core microbiome of microbes from the parent plant. If the parent plant is growing in soil that's bare for most of the year or there's big bare spaces between the rows or we're using fungicides that are eliminating a lot of very important fungi in the soil or we're using insecticides that are very detrimental to the whole ecosystem really then the chances are that the seed that's produced by those plants is going to have a defective core microbiome. And so with successive generations of plant breeding under those kinds of conditions, we end up with plants that are less and less able to be healthy. And we keep trying to prop those plants up with more and more fertilizers and more and more fungicides and more and more insecticides. And that is the path that we've gone down without realizing why it was that we needed to keep on using more chemicals. And we're seeing the same thing in human health as well that people are becoming less and less healthy. One word for that is epigenetics. In other words, the next generation is inheriting a less functional microbiome from its parents. And then the children of those children in turn inherit a less effective microbiome. It's got nothing to do with genetics really. It's got everything to do with microbes and applies equally to all living things.

12:38 So in this diagram here we have a bean plant on the left hand side and a rice plant on the right hand side. So they're in two different plant families and the black line along here obviously is the ground level and all the little dots all over this diagram represent microbes. So if we just look at this bean plant on the left hand side, we have the roots below ground obviously and all the microbes that live around plant roots are called the rhizosphere microbiome and that's the one where most research has been done and the one that most people are familiar with. I think just about everybody these days knows that there are microbes living around plant roots and that they're extremely important for many reasons. Then everything that is above ground, you know, the stems and the leaves and the flowers, the seeds, that's the phyllosphere. The area above ground is the phyllosphere. And there's also a phyllosphere microbiome. In other words, there are microbes on the leaves, in the leaves, on the stems, in the stems, on the flowers, and as I said, in the fruits and the seeds. And it is the microbes that end up in the seed that form the core microbiome which are really important for the next generation. But the microbes that end up in the seeds initially all the microbes are actually taken up from the soil or most of them are taken up from the soil. So if this isn't healthy, if we're planting seeds that have fungicides and insecticides on them for a start, we're having a really detrimental impact on that whole rhizosphere microbiome. So there's not going to be a functional microbiome for the plant to even be able to take up beneficial endophytes. And so we end up with a lack of beneficial endophytes in the core microbiome and then the next generation of plants is not going to be healthy either. And if you think about how that has happened over decades with plant health deteriorating over time, soil health deteriorating over time, we've got to the situation we're in now where if we pull everything from our crops, if we don't use nitrogen fertilizer, if we don't use phosphorous fertilizer, if we don't use fungicides and insecticides, we basically won't get a crop. And this is the unhealthy situation that we've got to because we haven't understood that the plant actually needs to function as a holion. It needs to have microbes in every part of it. And in fact, any part of the plant that you wanted to look at, if you looked at it under a high magnification, you would see in a healthy plant anyway, that there would be more microbial cells in there than there are plant cells. So if you looked inside a plant leaf at high magnification, you would see that there are a lot of microbial cells inside that leaf and that they're very important. So we have the things that live inside are the endophytes and the endophytes are beneficial microbes that live within plants. Endo is in and phyte is plants. So the endophytic microbiome is everything that lives within. So we have the phyllosphere microbiome is everything living on the outside. The endophytic microbiome is everything living on the inside. And the whole thing with all those different microbiomes is the holion. And then when we consider other plants that may be growing together and they all have different rhizospheric microbiomes and when we have a lot of different plants growing together in say a diverse pasture or in a diverse cover crop or in a companion planting which is becoming something that's becoming much more popular or in your wide rows with your interceding and all of the different kinds of plants that are growing together. Then we have what I called last week was the sociobiome. It's all the different microbiomes interacting and what happens then when we have lots of different microbiomes interacting and that's also a very important factor. It's not just the microbiome that's associated with one plant but what happens when we have lots of different plants growing together. So how can you tell that your plant is actually functioning as a holion? Well, if you pull some out of the ground

16:49 Take a look. This is a little grass seedling that I've just pulled out of my garden at home. Here's the seed here. And there's some seminal roots coming down from the seed. And everything is covered with soil, which means that it has a riser sheath. And these crown roots coming out from the crown of the plant. You'll see exactly the same formation in cereal crops. And these are also covered with soil, which means that they have a very healthy functioning riso sheath. A riso sheath is a column of soil around a plant root and there's going to be a lot of biological activity taking place inside that riser sheets.

17:31 If we see, well I'll show you in a minute what happens if we when we don't have that. And some people say riser sheets only form on plants in the grass family. It is true that grasses are good at forming riser sheets, but this is a little seedling, a little fork, and you can see that it's got aggregates forming all around the roots. And again, all of the roots are covered in soil. I can't see any white roots there. And this is a beet plant that Jesse Frost sent me this photo last year, and I used it in my presentation last year as well. But even though beets are non-microisal, they will still, if they're healthy, will still have riser sheets on the roots.

18:16 So if we look inside a riser sheath of a healthy plant, this is the plant root over here on the left hand side. And over here on the right hand side, we have the soil. And inside that riser sheath, we have an amazing world full of absolutely trillions. There are trillions of microbes living inside a riser sheath. And just to put that in perspective, we measure the human population on the planet in billions. There's something like about 7 something or other billion people living on the entire planet. But in that one photograph even, there are probably trillions of microbes. So it's an order of magnitude higher. What we can see at that level of magnification are all these fungal hy. And they will be lots of different kinds of fungi. Some of those will be symbiotic. Some of them are, in other words, they're forming a direct relationship with plants like tricoderma and microisal fungi, but a lot of them will be sapotrophic. And the more we study the soil, the more we realize how important the sapotrophic fungi are. In other words, they're just feeding off the exodates that are coming out of plants. We used to think that fungi and soil were mostly associated with decomposing organic matter. But now we realize the majority of fungi are actually associated with living plants and they're using label carbon, in other words plant root exidates. So they can feed directly from plants but they're not necessarily symbiotic. And these sapotrophic fungi will also have their own bacterial colonies associated with them. So the whole of the outside of the fungal hy will have a biofilm of bacteria. So they in turn are feeding bacteria and the bacteria that they are feeding are able to access nutrients for the plants in the same way that the fungi are able to access nutrients for the plants. So all of these things that are associated with plant root are there for a reason. They're there to activate nutrients including things like phosphorus. Very very important for activating phosphorus and very important for protecting the plant from pests and diseases. At that level of magnification, you can see some little drops of exidates coming coming out of that plant root. Now, 85 to 90% of plant nutrient acquisition is microbially mediated. In other words, it needs to go through a microbial process in order for the plant to be able to use it. And that's why it's really important that we have those riser sheets around plant roots. So, today's soils are not actually deficient in minerals such as phosphorus, but they are deficient in plant dependent microbes that are able to get those nutrients such as phosphorus. And I will talk a little more in a little more detail a little later just about exactly how the forms that phosphorus is in in soils and what it is that our plant dependent microbes need to do in order to make that phosphorus available.

21:14 But just before I get to there, I want to say why is it that we think that we need to add phosphorus to soils and why is it that we think we need to add nitrogen to soils? Like why have we come to that conclusion? And we've come to that conclusion because plant dependent soil microbes don't function effectively under most laboratory conditions. So, I've spent most of my research career working at a university conducting experiments with plants, mostly with cereals. And all of the soil that we used to do our glass house trials had been collected probably 12 months before and had been sitting in a big bunker for all of that time. Didn't have any plants growing in it. Any plant dependent microbes that were in there would have died in that time. And then we take that soil from the bunker and we homogenize it. Sometimes we sterilize it. We put it into pots. We put plants in it. And those plants are not going to grow well unless we add water soluble phosphorus and water soluble nitrogen because they don't have their other half. They are not holions. They are only half a plant. I think as somebody said in last time I did the phosphorus paradox someone said they were half bions which I thought was a great term. So they're not holian they're half bots and they can't work. It's like if you took the rin out of a cow it she cannot work and if we take the microbiome away from plants they cannot work. And what do they look like? When we look at plants that are only half a plant a half plant we can see the roots. We see all these what I used to think were lovely white roots on our plants. And that is not healthy because what that means is that the only way that that plant if it has clean white roots like that, the only nutrients it can get are the ones that are right next to the roots. And once that runs out, it's going to be deficient unless we apply more. And we're going to have to apply those things in a water-soluble form so the plant can basically just suck them up out of the soil by sucking them up through a straw.

23:32 And we have done decades of research on plants that look just like that. So you can throw out most of the textbooks, most of the research articles. In fact, anything that even today I will pick up something, I'll go, 'Oh, there's an interesting article on phosphorus or there's an interesting article on nitrogen.' and they've spent, you know, thousands of dollars, maybe hundreds of thousands of dollars doing this huge research trial. And I look and I go, 'Wow, it was either done in a glass house with soil that wasn't biologically active or was done out in the field with a monoculture in soil that was probably bare between monoculture crops or in soil that's been, you know, treated that way for decades. In other words, not in biologically active soil. So if it is not biologically active so yes you are going to get a response to nitrogen and phosphorus. If the plant is actually functioning effectively as a holiant you will not get a response to nitrogen or phosphorus because the plant won't need it because it can get its own. So we've come to the wrong conclusions about what plants plants need because we conducted the under the wrong conditions. But we didn't know that. I didn't know that. I didn't know that in the 1980s and the 1990s. And in fact, if you told me that you know there were farmers who were able to grow highly productive crops without applying any fertilizer, I probably wouldn't have believed you because I had a deeply held belief like most of us have that you have to apply fertilizer whether it's in your home garden or in an agricultural situation that it's a just a basic rule of life, right? Plant seeds, add fertilizer and that's what makes plants grow. And we all nearly all of us

25:22 Believe that and we have believed that for a really long time. So it's hard to get that out of our heads except that you have to remember that all of the experiments and all of the not even just the experiments that were done in universities but what we saw in the field in soils that were not biologically active for all the reasons that I mentioned mostly because we had too much bare soil and we had soil that was bare for too long. Remember that these plant these microbes are plant dependent microbes. We have to have plants there all the time. We have to have lots of different kinds of plants to actually stimulate that soil microbiome to make things like phosphorus available. And only the plants and the microbes actually working together can produce fertile, well structured soil. Because we don't only just want plants to be able to obtain the nutrients that they need from soil, but we want our soil to be well structured, too. And this is a really important part of the equation because those root exudates are the things that are not only going to signal to microbes and feed microbes, but those root exudates are going to be the starting point for soil aggregates and well structured soil. If we are feeding plants with a water-soluble nitrogen and water soluble phosphorus and they're not producing those exudates, they're also not building soil and on top of everything else that goes wrong like pest issues, disease issues, we end up with compacted soil as well.

26:52 So this photo, I did show this last week, it's become one of my favorite photos. This is Scott Raven Camp U with green cover and on the left hand side you see some compacted soil and on in the center there you see some soil that is becoming beautifully well structured simply because it's growing underneath an oat plant and in this situation there is no synthetic fertilizer being used and the plant is producing lots of exudates in order to get the nitrogen and the phosphorus and all the trace elements and everything that it needs. But in the process of producing those exudates to get the things that it needs, it's also building soil. It's building soft, porous, well aggregated, beautifully structured soil. So the soil building is the other thing that we need to take into account when we're talking about nutrients and nutrient acquisition. And we could look at that soil on the left and go, 'Oh, well, you know, maybe that's because this has been cultivated for decades.' Well, that could also be a deeply held belief that maybe it's not because it's been cultivated for decades. Maybe it's because there's been an annual crop grown for a couple of months and the rest of the time the soil has been bare. So, we have to take that into consideration as well. I just jumped over a slide there. I don't know why the planets are not aligned today.

28:20 So that well structured soil is structured because it has these humic molecules in it. And these humic molecules are composed of elements that came from the air. Carbon, oxygen, nitrogen hydrogen and they've all been polymerized. They've been joined together by enzymes from soil microbes. So the very process of photosynthesis that's going to be fixing carbon dioxide, the plant is going to be channeling labeled carbon into the soil microbiome. It's going to be activating and supporting a whole lot of plant dependent soil microbes. The energy is going to be transferred through the soil through the fungal networks. As I explained yesterday, the fungal energy channel is another term for what I call 20 years ago the liquid carbon pathway. And all of the life in the soil that is activated through the exudation of those carbon compounds and everything else that's related to that, that life in the soil means that our soil is now a living system just like a person really or an animal. It's a living thing that can form compounds like humus in the same way that a living thing like a human being can form compounds like bones and teeth and skin. And we make all those things by joining elements together. Our bones for example have calcium and phosphorus and other elements in them that are bonded together that they form very very strong polymers and our bodies did that. The biology in our bodies was able to take those elements and join them together and make all the things that we need in order to function as a living thing. So when the soil is living and has lots of different microbes in it from different functional groups, they can work together to take those elements and bind them together into the things that soil needs. And the most important thing that soil needs is humus. And because soil structure and water holding capacity and a whole lot of other things that happen in soil basically revolve around its humic content.

30:51 And that polymerization process that you're looking at there in that diagram cannot take place without microbial activity. And the majority of these microbes are getting their energy from living plants. And to form that molecule, the nitrogen that's in there, just to go back, the nitrogen molecules are the blue ones here are an intrinsic part of the humic molecule. It cannot form unless nitrogen is being fixed biologically in the soil. And I will talk about that a little bit next week in the nitrogen solution about how nitrogen is fixed biologically in the soil and how it gets into that humic molecule. But the important thing that I want to mention today, if I can get this to work, is that for the nitrogen fixes, in other words, the bacteria and the archaea that actually take atmospheric nitrogen and fix it in a plant available form and in a form that can be incorporated into a humic molecule are stimulated by phosphorus solubilizing bacteria. I know this sounds complicated. But nothing in the soil works alone. None of these groups of microbes work alone. Biological nitrogen fixing bacteria do not work alone. Phosphorus solubilizing bacteria do not work alone. One of the things that annoys me about the current research or some of the current research is I think oh here looks like an interesting article on phosphorus and what it will be will be about trying to isolate some phosphorus solubilizing bacteria from the soil. Multiply them in the laboratory or whatever and sell them to farmers. It's like here are some phosphorus solubilizing bacteria. You can put these on your seed and these are going to help you. They do not work alone. You have to have the whole suite of microbes that you would find around healthy living roots. All you really need to do as a farmer is get some diversity in there. Get some have green cover like all year or for as much of the year as you can and stimulate the plant associated microbes that way. It's not a matter of buying these things and adding them to the soil. And remember that they don't work alone. So if we in our wisdom think okay so our plants are need some more phosphorus they're not growing well enough we put some soluble phosphorus onto the soil we knock out phosphorus solubilizing bacteria because they're not needed we don't kill them but the plant just stops supporting them and if we haven't got phosphorus solubilizing bacteria functioning in the soil biological nitrogen fixing can't take place I don't know whether I've managed to explain that or not I realize it's complicated. The only thing that you have to remember is that you need to have lots of different kinds of bacteria or lots of different kinds of microbes really in your soil because your fungi are very important too.

34:02 So the point about that is that if the humic molecule contains nitrogen that has to be fixed biologically and we add water soluble phosphorus which inhibits water solubilizing phosphorus solubilizing bacteria that are important to activate nitrogen

34:18 Fixing bacteria then we are inhibiting the entire soil building process. I hope I've made that clear and that is the phosphorus paradox. We think we need phosphorus because we base that on what we see, but we're observing under conditions that aren't appropriate. We add phosphorus because we think we should. And what we do is cause a whole cascade of effects that are deleterious not only for plant health, but also for soil function and soil structure. And then when we end up with compacted soils, structural soils that look like concrete, and we add more phosphorus to try and get the plants to grow, and then we get a big downpour of rain or something and half our soil washes away, guess what happens to the phosphorus? All ends up down in the river, down in the lake, out to sea. It's a compounding problem. So we have to wind that back and think about how soil functions really.

35:24 And the other thing too about soil is what's become very popular is everybody talking about soil as a carbon sink. I mean it's not only what soil can do for our crop production and our pasture production but people are talking about soil as a carbon sink for removing carbon dioxide from the atmosphere. And we know that topsoil is really the most logical place to put that carbon because topsoil holds three times as much carbon as the vegetation does.

35:54 I don't know what's going on with this today. This has never happened to me before, but it's jumping over two slides at a time. Actually, this did happen in a green cover workshop one time. We won't go into that.

36:12 Two years ago now the world first and an Australian first was an Australian farmer issued Australian carbon credit union units accusing so carbon under our federal government's emission reduction fund and the reason I'm mentioning that is it's the first time anywhere in the world that a farmer has received carbon credits for soil under a government regulated scheme that is based on measurement. We've had proxy systems in the past like Chicago climate exchange for example. But this is actually measured carbon across his whole soil.

37:05 Okay, let's see if we can just do one slide at a time.

37:14 So in over a 24 month period, Neil has sequestered nearly 25 tons of CO2 per hectare, CO2 equivalents per hectare, which I find really interesting because it's measured in a government scheme. It's measured using all the protocols and they are strict. And just about every soil scientist in Australia for the last 20 years has been saying it is not possible to build soil carbon in Australian soils. And now we have a farmer in a 24-month period built 25 tons of CO2 per hectare or took 25 tons of CO2 per hectare out of the atmosphere and sequestered them in their soil as organic carbon. So in other words, that equates to 6.7 tons of carbon per hectare. So I'm not quite sure what those scientists have to say about that.

38:10 The interesting thing from my perspective was that 2/3 of the sequestered carbon was calculated to come from root exudates and the majority of the carbon was built, the carbon was measured down to 1 meter, say 40 inches, and the majority of it was in that lower part of that soil profile not in the topsoil. So where the carbon was building was down deep and that was as a result of root exudates. So here we come to this photograph that I used right at the beginning of this talk. These are the things that are going to build soil for you as well as support plant in terms of its nutrient. Now Neil Zolen has not used any nitrogen or phosphorous fertilizer for the last 20 years but he reports that his farm has become more productive every year. So what is the secret? Plant diversity and this is a pasture situation but how does Neil get diversity? He's invented this machine called a soil key renovator and he basically goes over what you can see there on the right hand side is probably this is Victoria so would be just a ryegrass pasture and he's going over it with a machine that's basically like a strip tillage I suppose it tills, he has calculated 17% of the soil and it's only tilling it very shallow depth like 1 to 2 inches and just creating a seedbed to be able to put diversity into that monoculture of grass. And by doing that every year, he'll come back over it and over it like each time planting over the same area again and putting a diverse mix of plants in and grazing those. That's how he has increased his soil carbon. He's done it through year-long green and plant diversity and not using fertilizers.

40:04 So what is it about phosphorus? What are the key points about phosphorus that we need to know? A couple of things. One is that only 10 to 15% of any phosphorus that we apply as fertilizer will be taken up by plants in the year of application. Now think about that when you're looking at how much money you are spending on phosphorous fertilizer. Remember, plants are only taking up 10 to 15% of that. So the other 85 to 90% is being immobilized in the soil and it's not directly available to plants. And once it's actually become immobilized, unless it's activated by microbes, that's basically it. So every year you're putting phosphorus on and most of it's going into what we call the soil phosphorus bank.

40:51 How is it being immobilized? Well, if the pH is less than seven, in other words, in an acid soil, it's going because phosphorus is very reactive and phosphate has a negative charge, it will form insoluble compounds with aluminum and iron or manganese. So it's going to form aluminum, iron or manganese phosphates. And once those compounds have formed, plants can no longer get that phosphorus. If the pH is above seven, in other words, an alkaline soil, the phosphorus is going to bind with calcium and it's going to form calcium diphosphate or calcium triphosphate and those are insoluble. Once the phosphorus has formed those compounds, they are not available to plants. And the other thing I did mention earlier that phosphorus doesn't move in the soil unlike nitrogen which does, especially when it's nitrate will rapidly move through the soil profile. But in the absence of erosion the phosphorous fertilizer that you've applied moves no more than 1.5 to 2 inches from where it was placed. So in a pasture situation if it's placed on top of the ground it's virtually useless really because not that many roots feed from the top of the ground. And in a cropping situation where it's placed somewhere near a seed, that's basically where it's going to stay for the rest of the time. And once any roots get down, 6 inches, 12 inches, 30, 40 inches, whatever, down into the soil, that phosphorus that's been placed right near the soil surface is not available to those plants. So we're spending enormous amounts of money putting something that is rapidly immobilized and can't move to where the roots are anyway in the soil.

42:41 And how much of the phosphorus is available when you do a soil test. And it's going to be a Bray test or a Morgan test or a Colwell or an Olson P test. There's a dozen different soil tests that will tell you how much phosphorus is available. The available phosphorus is going to be a very very small amount of the total that you have in your soil. So for Olsen P, which is the test that's commonly used in New Zealand, and at the bottom of the soil test result, it will tell you how much of that is what fraction that is of your total phosphorus. I don't know whether other kinds of soil tests say the same thing.

43:27 Available phosphorus with an Olson P test. If you have a high anion storage capacity soil, in other words, a soil that has a high affinity for phosphate, it's going to show you 1.4% of the total amount of phosphorus. And if you have a low anion storage capacity soil, it's going to show you 3% of the total phosphorus. In other words, basically in any soil anywhere in the world, your available soil P test is going to tell you somewhere between 1 and a half and 3% of what's there. The other 97% or 98.5% is not going to show up on your soil test and then you'll go out and you'll spend money on buying more phosphorus.

44:08 So it's the least mobile, the least available of the essential elements in soil and for that reason it's often the major limiting factor for plant growth. This is a diagram that I put into the phosphorus paradox which is in the soil health resource guide. But over here on the right hand side you can see the available P in other words the phosphate. This is going to be what you will see on a soil test and that what's in the soil solution is basically what will be called available P. And remember that's between 1.5 and 3% of all the phosphorus that you have in your soil.

44:53 So over here on the left hand side we have phosphorus that's in the inorganic or the organic form. So if it's inorganic, it's what I was talking about before. When you add phosphorus as fertilizer, it is probably going to be very rapidly absorbed onto aluminum, iron or manganese and become it's part of the mineral pool. Then it's inorganic and plants can't readily access that. The organic pool is that that's associated with other living things in the soil and with the carbon compounds in the soil, but it is equally unavailable. Plants are not able to access phosphorus from the organic pool easily. You'd think that they would be, but they're not actually able to because in the form of phytates and things that are just basically plants just can't take those up from the soil. So when we add water soluble phosphorus here, it very rapidly immobilizes over to here. But what we want to do is actually have it being solubilized and mineralized and moving back this way.

45:58 And the key to having that solubilization and mineralization is here. It's the bacteria, the archaea, the fungi, protozoa, nematodes, macroorganisms, everything, that whole all the microbes and soil fauna are important in the solubilization and mineralization of phosphorus. So it's not about adding more here. It's about activating this cycle. And this is where we have to concentrate our efforts if we want more of it to go this way and less of it to go this way. And the great thing about it going this way through biological activity is that it's going to move into the available pool when plants need it.

46:43 So if plants are actively growing, actively exuding labile carbon from their roots, actively supporting that whole fungal energy channel that I talked about last week. Fungi are great at solubilizing phosphorus. That's one of the things that they do really, really well. And all the different kinds of fungi in soil are able to do that. So if we really activate that fungal energy channel, we can move this quite quickly this way. And when that channel is open and plants are actively photosynthesizing and exuding carbon into that fungal network, in return, they'll be receiving all the phosphorus that they need.

47:27 And it's not going to be going anywhere else where we don't want it. It's going to be going directly into plants on that superhighway that's formed by the fungal mycelium. So it's not going to end up down in the river. It's not going to end up in the lake. It's not going to end up out in the ocean. And the great thing about it is that we don't have to buy it because we're just going to activate what we already have. And all of you have sufficient phosphorus in your soils if you activate what's there.

47:53 This is some data from New Zealand. It just goes to show you over a 12-month period how microbial activity affects the amount of phosphorus that's in your soil. So this is a measurement of several different kinds of elements. We have magnesium and phosphorus, potassium, calcium, and then it's looking at soil pH over time. But this is over a 12-month period. So we have January, February, March, April, May, whatever across the bottom here. And you have to remember that this is down under. So our seasons are upside down to yours. So the middle of the year for us down under is summertime and Christmas time is oh, sorry. The middle of the year is winter time and Christmas time is when it's hot and so not much microbial activity in summer.

48:49 So here just looking at the phosphorus, I think the next one is actually just a closeup of the phosphorus one. But just remember we're looking at it over a 12-month period. If I can remember which hemisphere I'm in I'll probably get this right. So here we have summer, here we have fall. Here we have the middle of winter. And here we have spring. And here we go into summer again. And look what's happening to phosphorus over that time. This is over multiple years, measured multiple times over multiple years. What it shows you is that when it's hot and dry or if it's cold and microbial activities are low, that's when the phosphorus levels are going to be the lowest.

49:27 It doesn't get terribly cold in New Zealand, by the way. In the North Island, this is the North Island of New Zealand. It's only a small island. It has a maritime climate, not cold like what you have in Nebraska. But we have this amazing peak here in the fall and then another peak in spring and this is also when microbial activity is at its peak. So what happens in New Zealand is that the agronomist will go out and take soil samples here and then tell the farmer that they need to add phosphorus because very low in their soil but if they waited until April it would be like 50% higher.

50:03 So what do we need to do? And one of those things that that graph actually shows you I think is the fact that this is what microbial activity can do to the level of phosphorus in your soil. You remember we just looked at this straight line here for example. I know that's not what that straight line represents but just imagine that it did. If that is the total amount of phosphorus and the total amount of phosphorus does not change over the year. You've got the same total amount of phosphorus all year, but the available level goes up and down depending on the level of microbial activity. So just to see this increase in microbial activity here goes to show you what change that can make to the availability of phosphorus. So we have to put our emphasis on stimulating biological activity and we will see that same kind of increase in availability.

50:55 It's just jumped over two slides again. I have not ever had this happen before. So if we want to improve the levels of soil carbon, our organic nitrogen, our organic phosphorus, you wouldn't believe this. I've just got a massive cramp in my lip. It's going to be one of those days. All of those things are going to come back to all of the nutrient cycling, the soil structure, plant health, all going to come back to optimizing photosynthesis.

51:28 And the best way to tell that is not going to be through a soil test. It's going to be through using brix readings on our plants. And we need to take herbage tests to see actually what has got into our plants. A herbage test or a leaf test, a tissue test, whatever you call it, is going to be far more useful than a soil test in terms of assessing whether your plants are actually able to access phosphorus in the soil. And they're going to tell you what's being made available, what's moving into plants, and what's moving through the soil microbial community.

52:01 And some microbes are able to produce phosphotase, which is the enzyme that actually makes that fixed phosphorus available to plants. And so they are the microbes that we need to be supporting and the best way to support those as I've said several times is through plant diversity. If it's a pasture situation then we need to have strategic grazing and we obviously need to have biology friendly fertilizers or preferably bio stimulants.

52:32 And if soils are healthy you will not obtain a response to added phosphorus. I think I mentioned that right at the beginning. And if you apply the last 10 years and only use 10% of it, you now have enough for the next 90 years plus what was already in your soil to start with. We have to see changes actually have to take place in the soil microbiome to enable farmers to reduce their inputs, restore soil health and also to increase soil profit. So which future are we going to choose?

53:01 We can continue with business as usual with the use of high analysis fertilizers which means we will have high input costs because not only will we be using the fertilizers but then there's the fungicides and the insecticides and everything that goes with that. We're going to have deteriorating soil function and negative environmental outcomes. I mean everyone's aware that all those things are happening. Or we can choose regenerative agriculture which I think is a term that's been overused unfortunately, but the basis of that is going to be in place of high analysis fertilizers. We need to use plant diversity and bio stimulants. We will have improved soil function. It's all about the function of our soil. We'll be able to reduce our input costs and we'll have increased plant, animal, human and community health. Because we have to think about the people that are consuming the produce as well and sequestration of soil carbon. I think that might be the end of my talk.

54:00 And some I have managed to get a massive cramp in one of my legs from sitting here. I'm just hoping that it's going to go away. That's a bit better. Okay.

54:13 Well, we'll pray for your cramped leg and that everything on the technology side continues. So I'm going to keep my video hidden that way, hopefully. I'm still having internet problems but maybe it'll work. So have we got, have you still got internet access? Is everything still going okay?

54:33 I'm hoping so. As long as you can hear me.

54:36 Yeah, I can hear you, so I guess so.

54:39 Okay. Well, one of the things that we've talked about is that we're going to take a lot of audience questions in this, but like I said, we had a lot of feedback from last week. And so one of the things that you and I had talked about was a question that we received last week that I think would tie into this topic very well. So before I get into this week's Q&A, I want to talk about the law of minimums in regards to not necessarily just phosphorus but as far as practicing regenerative agriculture. Are we more likely to fulfill the needs of the law of minimums versus trying to identify and throw synthetics at the soil in hopes of resolving the lowest hole in the bucket? If you can kind of give me your thoughts on that.

55:28 Yeah. Well, Justus von Liebig came up with that, well, actually someone else came up with it and then he coined the phrase. The law of the minimum basically says that if you're looking at that in terms of plant growth, whatever is the most limiting factor is going to be the thing that it doesn't matter how much you could have everything else in excess, but there is something that's going to be the limiting factor. And I think that definitely would apply to something like water. It wouldn't matter how much fertilizer you applied if there's no water where plants can't grow. But when we're looking at nutrients in the soil and we start adding synthetic fertilizers, the law of the minimum becomes a little bit blurred because there might be things that really are essential for plants like zinc for example. It's something that plants need in order for their immune systems to function effectively, for them to have immunity to pests and diseases. And zinc is a really important factor. And also the fact that plants need to be able to take microbes from the soil when they're stressed like in a drought situation or where there's a pest issue or a disease issue. Plants will often recruit microbes from the soil to help them in that situation, whereas in a healthy situation or where everything was non-limiting, they wouldn't. So sometimes that ability to recruit microbes from the soil can become a limiting factor too.

56:53 So let's just say we have a situation where the soil is dysfunctional and we're adding lots of water soluble N and lots of water soluble phosphorus and so those things are not limiting. And the plant is able to grow but it's not growing well because it doesn't have all the trace elements and things that it needs. So even though it should have beneficial endophytes in it or should have zinc in it, it doesn't have. So that the law of the minimum would say well if it doesn't have sufficient zinc that will be the thing that will limit its growth. But what will happen if we add nitrogen and phosphorus is that it will still grow. And when we add those two things, they're the two most vital things apart from water, I guess, and carbon dioxide, it will still grow, but it's not a healthy plant.

57:49 I'm not sure whether I explained that very well, but in a natural system, if we were looking in the prairie for example, the law of minimums would apply. Whatever was the limiting factor would be the thing that would limit plant growth. So if for some reason something like boron or molybdenum or zinc or something was a limiting factor or nitrogen or phosphorus was a limiting factor then the law of minimum will apply in that situation. But in our artificial agricultural situations it doesn't really apply because we throw everything out of balance. I'll probably totally confuse the issue there with that answer. But what happens is the plant will still grow. The law of minimum doesn't apply. The plant still grows but it's dysfunctional and then we need to apply fungicides and insecticides and things because it doesn't have the trace elements in it that it should have. That's probably the answer that I was meaning, or it doesn't have the endophytes in it that can help it to fight pests and diseases.

58:49 That made perfect sense to me but I can't speak for the rest of the audience. I think that was pretty good. The next one as far as the topic, this isn't really a question, but on aerobic versus anaerobic, which I know you're going to be touching on next week, so this is kind of a teaser for the nitrogen solution. But talking about nitrogen fixing microbes not being able to function in the presence of oxygen.

59:14 Yes, that was something there were quite a few questions about that last week about me talking about fermented composts and things being produced in a fermented type medium like vermy liquid for example. And the question being well shouldn't soil be aerobic? Well in actual fact soil is a mix of aerobic and anaerobic microites. If we look at the aggregates for example, the water stable aggregates that we want to see forming around plant roots, the inside of an aggregate has a low partial pressure of oxygen which is the only reason that and I forgot to mention that actually when I was showing that slide of the humic molecule that's got nitrogen and carbon and hydrogen and oxygen, everything all formed together in a polymer, that polymerization process and the even the

1:08:30 Wait a little bit. That's deep. That's the answer to that question. You mentioned there about, you know, if your tissue test is saying that you're lacking something, it's okay to add things to that. So, I think that kind of answers Ry's question, but Odet asked, 'What is the best way to get a bricks reading or a bricks analysis?' Do you have any recommendations on how to do that?

1:08:54 So just to wind back a minute. Noah to that other one, if you do a leaf test and it's recommending that you need to add something, in most cases the best way to add that is then as a foliar, so you're actually going to apply that to leaves. Leaves will absorb those elements, take them into the plant, and you can use a much lower amount than you would need to use if you put it in the soil. The problem with putting fertilizers in the soil is that you, you know, disrupt the whole soil microbiome and you disrupt that signaling and that communication that goes on between plants and the soil. Whereas if you put it on the leaves, if they need it, you do a leaf test, you see that plant is deficient in something, you add it to the leaves, they can absorb it through the leaves, and then you're not interfering with anything that's going on in the soil. The only caveat to that is that there are a few trace elements that aren't readily absorbed through leaves and you'd need to talk to the lab about what those are and what the best way of applying those.

1:09:47 In terms of bricks, you would measure that using a refractometer. You can get one on the internet, just Google refractometers. You need to make sure that you get one that goes from 0 to 30 or 0 to 32. You don't want one of the ones that just goes from 0 to 10. And you want to get one with a scale that's really easy to read. I think these days most of them are very easy to read. Some of the early ones that were made, but that was like, you know, 20 years ago, were a bit hard to read. And you need a garlic press or some other way of actually extracting sap from your plants. So, if you're looking at your crop or your pasture, you need to take some leaves and scrunch them up, put them in a garlic press, and press some sap out of them, put it on your refractometer, and away you go.

1:10:38 There's all the instructions that you need are all going to be on the net. Yeah, how to use a refractometer. You'll find all the information you need. You'll find tables on there about what levels you would expect to find in various plants. Obviously different things, you know, an apple's going to have different levels in it to grass, for example. And it'll tell you what's low, medium, or high for all the different sorts of plants. There's tables of bricks. You'll find everything you need to know about bricks and about refractometers on the internet. And you should be able to get a refractometer for, I don't know, $50 American or something like that. Less than $100 anyway.

1:11:20 Okay. Do you have any thoughts? And I apologize if we touched on this last week, but do you have any thoughts on adding wood ash or biochar to fields?

1:11:31 Wood ash is extremely alkaline. Wood ash, like in its pure form, has a pH of somewhere around about nine. So, you would want to be very careful about how much you added. If you have acid soils, I guess a little bit of wood ash wouldn't go astray. I'm not really sure why you would be adding it other than maybe as a remedial thing for if you do have very acid soil. In other words, it would just be like adding lime. I guess you can kill plants with wood ash. I know from experience because I've got a wood fire and I've killed plenty of plants in my garden, and I thought that wood ash would be a good thing, and I'd put it on plants, and then they'd die, and I thought this is really strange. So, I did a pH and then I checked it on the internet when all else fails, read the recipe, right? And I went, 'Oh my goodness, pH of nine.' So I checked the wood ash out of my fire, and yeah, sure, that's where it is, up there. That's very alkaline. That's very toxic to plants in its pure form. So, I don't really know why you would want to be adding wood ash unless you did have very acid soil. As far as biochar goes, again, why would you be adding it? Like, what is the point? What are you trying to achieve? What we want in soil is to open that fungal energy channel through plant root exudates. We want more photosynthesis. And we're going to get more photosynthesis by having green plants for as much of the year as possible and by having as much diversity as possible in those communities of green plants. I'm not really sure where biochar fits into that.

1:13:12 Okay, if you thought I butchered potash, you're going to love this one. Which produces more phosphates, bacteria, fungi, or actinomycetes?

1:13:25 Actinomycetes? I'm hoping you know what that is because that went over my head. No, you got it right the first time. I think actinomycetes. Yeah, actinomycetes. I think that's how I'd say it.

1:13:40 Yeah, that's like how long is a piece of string? I mean, all microbes are able to produce enzymes that liberate phosphorus. And it's going to depend on whether they need to, whether the plant is sending signals to them saying that it needs it. I mean, how many different kinds of fungi are there? How many different kinds of bacteria are there? Like, we're talking about thousands of species of these things. Yes, they all produce different amounts. They all, I mean, even if you took one species of fungi, for example, people have been trying to make isolates of, like, they'll take one species of fungi that's able to produce phosphatase enzyme, and then they'll compare different isolates of that fungus. They'll go and get it from different locations, different soils, try to find one isolate of that one species of fungus that can produce more phosphatase enzyme than the other ones. And then they'll say, okay, we've got this one variety, if you like, one isolate of a fungus that's able to produce lots of phosphatase enzymes. So now we're going to regenerate this in the lab or multiply this in the lab. We're going to sell it to farmers. But having that one type of fungus that's able to produce lots of phosphatase enzyme, and you put that out in your soil, soon as you put it out there, everything that's living in the soil at the moment is going to eat it anyway. It's going to be consumed. It's never going to survive.

1:15:10 The only way that you can actually have lots of different kinds of fungi producing phosphatase enzyme is to feed them from living plants. So again, it comes back to photosynthesis, comes back to green cover, it comes back to plant diversity and the sort of things we talked about last week of the soil biome. When we have microbiomes that are very different that are in close proximity, they will cooperate to make more resources available to the plant community. So those microbiomes will actually cooperate to support fungi, and the fungi will actually probably be joining all those microbiomes together anyway to produce phosphatase enzymes. So the one species of fungus is going to produce different amounts of phosphatase depending on the situation that it's in. So there isn't really, you cannot say that bacteria produce more phosphatase than fungi or fungi produce more than bacteria, because you know there's so much variation within that whole, yeah, you're talking about whole domains of living organisms that contain thousands of species and are all operating under different conditions. It doesn't really mean anything. We can stimulate the whole soil microbiome without even knowing what's in it, simply by maximizing or optimizing photosynthesis. You don't even have to know what's going on in the soil. We can stimulate the

1:16:33 Whole lot. And the more different kinds they are, the more they're going to interact better anyway. You know, they're going to cooperate more and liberate, if you like, more phosphorus if there's more variation in the kinds of microbes. So we want bacteria and fungi and actinomycetes and every other thing that lives in the soil all working together in cooperation with plants to make the whole thing function as a sociobiome.

1:17:09 Can you please explain a little bit how applying synthetic fertilizers, in this case specifically phosphorus, might inhibit phosphorus solubilizing organisms from functioning? Are you saying that they will leave the area because they don't need any more phosphorus?

1:17:27 Okay. So what I'm saying is that applying water soluble phosphorus in itself is not toxic to the soil. What it does is the plant will now have the water soluble. It will now be able to take that water soluble phosphorus up through its roots because it can just suck it up like drinking it up through a straw. And the plant is now got the phosphorus that it needs. It is going to stop producing root exudates to support phosphorus solubilizing microbes. And if they're not being fed anymore, they're basically going to starve to death. You the plant is very selective about what it feeds and what it supports in the soil microbiome. Under different conditions, it will support different microbes. When it needs phosphorus, it will support phosphorus solubilizing microbes. When it needs nitrogen, it will support nitrogen fixing microbes.

1:18:26 I mean, one of the classic studies which I think was done around 1982, I'm not sure whether that's exactly the date, but it was quite a long time ago given that back in 1982 we really didn't know very much about how soil functions. And it was a study that was done in the United States, and it was a grazing study where what they found was that if you had a grass plant and you looked at what was happening around the roots of that plant, and then you grazed it, the plant now needs to regrow. And the most important thing that a grass plant needs to regrow is nitrogen. And like minutes after it had been grazed, it suddenly started exuding from its roots lots of signals to nitrogen fixing bacteria, free-living nitrogen fixing bacteria in the rhizosphere. And the numbers of free-living nitrogen fixing bacteria in the rhizosphere exploded within minutes of that plant being grazed. So the plant is sending a signal to the soil microbiome like help, I need nitrogen. I need to regrow. Why would the soil microbiome respond? Like does the soil microbes care whether the plants grow or not? Well, yes. The soil microbiome is going to respond because this is a holobiont. The soil microbiome is the other half of the plant. And if the soil microbiome responds by an exponential increase in the number of free-living nitrogen fixing bacteria around the roots of those plants, fixes lots of nitrogen, gets the plant going again and photosynthesizing again. Who's going to benefit from that? The plant will benefit but so will the soil microbiome. So everything else that's in the soil microbiome will now be able to get more root exudates because the plant has regrown. If the plant is heavily grazed and it's just sitting there with no leaves or very few leaves, there's not much energy coming into the microbiome. So there's always this ongoing conversation between the above parts of the plant, in other words leaves and not only the roots but all the microbes that are living around the roots.

1:20:42 Now that was a long time ago, 1982. I mean that's gosh nearly 40 years ago that we knew that plants can communicate with the soil microbes in that way. And I guess it's the same in that situation: the plant needed nitrogen so it signaled to nitrogen fixing microbes.

1:21:06 If we had apply, if we had grazed the plant and then applied nitrogen, which is what a lot of dairy farmers in New Zealand and Australia do in pasture-fed dairy. The minute the cows come out, they will come in and spread urea across the whole paddock. The plant doesn't need to send those signals to the roots because the farmer has just applied water soluble nitrogen. So it's not that the plant or anything is killing the microbes. It's just that the microbes are no longer being supported. And when those microbes aren't being supported, the plant is not building soil either. So you end up with compacted soil, even though you may have never ever plowed it. Just because soil structure needs to be continually supported by ongoing additions of polyaccharides and things to the soil that form those glues and gums that stick all particles together to give it structure. And if there's not an ongoing supply of root exudates to support soil structure, it will deteriorate. We will end up with compacted soils. You can end up with compacted soil simply by applying water soluble nitrogen or water soluble phosphorus, which takes away the job of the plant in supporting the microbes if that makes any sense. Those things of themselves are not necessarily poisonous to soil microbes but the plant just stops feeding the microbes. And if the plant doesn't feed the microbes, no one else will. So microbes are going to, you know, microbes have very short lifespans. I mean, a bacteria, for example, might only live for two minutes. They're not around for a long time. And in that short time, what they're doing is feeding and multiplying, feeding and multiplying, feeding and multiplying, and also doing whatever it is that they do: fixing nitrogen or solubilizing phosphorus or something. There's very rapid turnover so that as soon as you stop feeding them, they're just going to die out very, very quickly.

1:22:59 One of the questions I got a lot from last week was in reference to the four groups of biodiversity that you mentioned and I don't know if you want to kind of clarify that. Virginia is asking what are the four groups of the biodiversity and what would you recommend in the garden, multiple plants in the same row? How do we know how to do that?

1:23:24 All right. So the term for functional groups that I mentioned last week came from the Jena biodiversity experiment in Germany. And that was in a perennial pasture situation. In that situation, the four functional groups that they were talking about were grasses, legumes, short herbs, and tall herbs. And when they said short herbs and tall herbs, they mean non-leguminous herbs. So legumes they're putting in a category of their own. So legumes would be things like alfalfa and peas and beans and you know in your home garden there'd be lots of legumes that you would grow. And then non-leguminous plants would be things like say sunflowers. Or if you were talking about the home garden, there are so many non-leguminous plants that you can use in the home garden to give you that functionality in your soil. So there's all the things in the what used to be called the Umbelliferae family, now called Apiaceae, like carrots and parsnips and parsley and coriander and all those things are all in the same family. So that's one functional group if you like, but they're things that you can put in underneath all your other vegetables. They don't take up much room. They cover the soil. They're photosynthesizing and it's a different plant family to, if your other plants are like, we'll say corn is going to be in Poaceae. Tomatoes are going to be in Solanaceae. Lettuce are Asteraceae. They're actually in the daisy family. Most people don't realize that, but if you let a lettuce go to seed, it forms these little tiny daisy flowers. And you've got everything that's in the carrot family. You've got the Allium family like your onions and garlic and all those sorts of things. And then you've got this amazing.

1:25:09 Range of herbs like borage which is in Veraginaceae, which is not surprising. Origin Boraginaceae but fossilia is also in Veraginaceae. You've got flax that you can use, which is in Linaceae, that's a family that you can easily put anywhere through your vegetable garden because it doesn't take up much room. It's got wonderful soil building characteristics. I mean the vegetable garden or even your flower garden is the easiest place to get plant diversity and easiest place to get so many different plant families. There's about 14 plant families that you can use in your home gardens.

1:25:45 In grazing pastures in a cropping situation, you're probably down to more like about 8 or 10 plant families that you can use in your cover crops and your companion crops. People are experimenting with some great companions. Ian Gould at Oak Bank in England is in his oil seed rape, canola in Australia. He's putting fenugreek, which is in Fabaceae, but fenugreek has a really strong aroma and it deters cabbage moths and other insect pests of plants in the Brassica family. So your canola is going to be a Brassica, then you're adding fenugreek, which is in Fabaceae. He's also putting vetch in there and he's putting flax in there, which is in Linaceae. So in actual fact, he has four functional groups in a crop or in your home garden simply by having four different plant families.

1:26:54 If you're not sure what family a plant is in, just ask Dr. Google. Dr. Google knows everything. So you know what family are peas in or what family is corn in or what family is millet in or what family is lettuce in, and you'll get the answer and you can start compiling a list of all the different plant families. Make sure that in your home garden or in your companion crop or in your cover crop mix or whatever, make sure you have at least four different plant families in there, preferably more. It's not that hard to get six. Eight's a little trickier. In a pasture you can get heaps, and in a home garden with all the different herbs and things that you'd be able to use, you could get up to 14 plant families all mixed in together. It would make a huge difference, especially if a lot of those are flowers. If you make sure you get your flowers in there, if that answers the question.

1:27:59 Yeah, I don't want to take too much more of your time, but the majority of the rest of these questions all kind of revolve around okay, we know that our soils need to be weaned off of this. How do we go about it? Do we just go cold turkey? Do we use biostimulants? Humic acid has been thrown around. What are people supposed to do or what do they take from this presentation and make an applicable change to try and do better as they move forward?

1:28:36 That's a really good practical question, Noah. I can understand that that's probably the situation where most people are at, that they are using conventional fertilizers and they're costing a lot of money and they're realizing that there's downsides to that and probably no future in continuing to do that. But you can't just go cold turkey and pull all that out of the system because over generations, our plants have become dysfunctional. They don't have an effective core microbiome. So this is one place where biostimulants on the seed become a really important part of making that transition.

1:29:12 Just to go back to the first though, to begin with, if you start using a biostimulant on the seed, you can stop using phosphorus fertilizer straight away, but you will have to wean off nitrogen slowly because it does take nitrogen-fixing bacteria about 3 years to build up to full capacity in the soil. If you've been using nitrogen fertilizer, you will have to wean back over a three-year period. So cut it back, you know, 20% 20% 20% sort of thing. With phosphorus, provided you put a biostimulant like a vermicompost liquid or a compost extract or something like that on the seed, you can stop using phosphorus straight away. In fact, it would be quite detrimental to use phosphorus and biostimulant at the same time. You're just canceling each other out.

1:30:00 The advantage of putting a biostimulant on the seed is that what you actually want to do is put the chemical signaling molecules of microbes on the seed. You're not putting microbes on the seed. You're putting the biological molecules that microbes produce when they're in a medium like in the gut of an earthworm or in compost or something like that, when they're actively doing all the things that microbes do. They're signaling to each other and it's those signaling molecules that you want to put on the seed. They're called autoinducers. If you Google that word, you'll find out that autoinducers are the chemical signals that microbes use to communicate with each other.

1:30:50 If you put those chemical signals, those biochemical signals on a seed, the plant as it's germinating is going to interpret that as being lots of microbes there, because the only way that the plant can know or sense whether there's microbes there is through those biochemical signaling molecules. You're putting biochemical signaling molecules on the seed. The plant will detect that there is lots of microbes out there and it will produce lots of exudates to feed those microbes. In actual fact, the microbes aren't there, but there will be dormant microbes in the soil that will be activated by those exudates. So you're now going to be stimulating dormant soil microbes to grow and form a relationship with that newly germinating plant.

1:31:41 The plant is able to take some of those microbes in as endophytes as it grows. The whole process that starts with putting a biostimulant on the seed is designed not to replace fertilizer as much as to stimulate the soil microbiome and start that process of the plant actually becoming a holobiant again and being able to form a good rhizosphere microbiome and to be able to use soil microbes to internalize them and use them as endophytes for all of the things that it needs during its growth, and then to be able to incorporate those into its own core microbiome in the seed for the next generation. You can start that whole process of revitalizing your plants, re-energizing your plants by doing that.

1:32:28 I would highly recommend that you keep your own seed because then it's got a better core microbiome and you're going to find that every generation you're going to have the advantage of having more functional plants each time. In the first instance, you might try getting seed from somebody that is already producing plants in that way. I know that seed is your business there at Green Cover, but it is really important that people know where the seed came from, how it was grown, and actually does the seed have a good core microbiome. If you're going out and buying a stallion or buying a bull or buying a ram or buying some livestock that you wanted to have good genetics, you're going to check up. If you're going to spend a lot of money on an animal you're going to check up about its performance. With seeds we just say okay, well we can just buy some corn or we can buy some wheat or something. We actually don't know very much about its core microbiome. I think that's something that people are going to need to start checking on and wanting to know how the seeds were grown.

1:33:44 Grown with lots of nitrogen and fertilizer, lots of nitrogen and phosphorous fertilizer, you're already at a disadvantage because those seeds are not going to have a very good core microbiome. So we can reset that by growing seeds with bio stimulants and through successive generations we will have healthier and healthy seeds. And we also obviously we need all of the things you know cover crops between cash crops, diversity in our covers. We need companion plants in our cash crops. You need all the great techniques that are being developed like you know 60-in corn with multispecies into rows and all of those things. All the different variations of polycropping if you like to have plant plant diversity and have the soil with living plants in it for as much of the year as we possibly can. And to get right away from using synthetic fruits, using bio stimulants, keeping our own seed, only ever buying bare seed. Don't buy seed that's got fungicide or insecticide on it. There's a whole lot of things are going to be important and it's all the pieces of the jigsaw really to put that whole picture together.

1:35:00 And if somewhere along the track something happens like when the soil is still dysfunctional and your plants are still dysfunctional, you know, you might there might be some outbreak of a of a pest or a disease or something. Well, you're going to have to use a fungicide or you're going to have to use an insecticide. I'm not saying don't use those things. You don't want to lose a crop because of not using those things. You want to try not to. Definitely don't use a fungicide unless you have to. But if you put in a situation where you do, you say, 'Okay, so we're just taking one step back and next year hopefully, you know, things will get better.' And over time as you build that whole plant community and a whole soil ecosystem and everything becomes a functioning sociobiome, the need for intervention with insecticides and fungicides will become less and less. And you'll get to the point where I know lots of farmers now who haven't used any of those chemicals for 10 or 15 years. Because they haven't needed to. It's not that they've got, you know, that they're strictly organic or anything. They just haven't needed to use those things. And that's the point where we want to get to where you go out, your crop is really healthy, your soils are building, you can see the improvements in soil structure, you can use a refractometer and see that you have high bricks. You'll get higher seed weights like the nutrient density. You'll be higher in seeds, you'll get better germination rates with seeds, better establishment. The whole thing will just build and build and build. But yes, it's going to have to be a stepwise process. It's not going to happen overnight. And you have to recognize, and I'm sure everybody does, but our soils at the moment, most of our soils are incredibly dysfunctional. They really are not working as soil should. And I would say that most farmers unfortunately in this day and age have not seen healthy soil. You'd have to go back, you know, 100 years or something to see really healthy soil. It's such a pleasure when you do see it. And I just hope that more and more people will get to see healthy soil and will build healthy soil.

1:37:11 You know, it shouldn't really take that long if you get really really working at removing as much of the deleterious effects as you can and really supporting as many of the you know stimulating things that as you possibly can the things that are going to activate. Remember that the soil, even though it's dysfunctional, has lots of dormant microbes in it. And they're amazingly resilient and it really, you know, just a little bit of kindness goes a long way when it comes to the soil. It doesn't really take that much to stimulate them. But we have to think, well, what is it that naturally stimulates soil microbes? What do they respond to? And they respond to plant root exudates. It's not any more complicated than that.

1:37:59 All right. Well, thank you so much. That was a very very good answer, thorough. I hope we got everybody's questions at least somewhat answered there. And if we did not, I did take pictures of all the questions that I can send to Christine afterwards. And if you want to send them to me as well, if you're watching the recording here, my email is Noah, that's n o at greencoverseed.com. This video here, this recording will be available here in probably the next two days. And if you missed last week's, that is on our YouTube channel already as well. So we would encourage you guys to go check that out. And if you've signed up for this, we automatically have you for next week in the nitrogen webinar. So we're excited for that as well. Hopefully with less technical difficulties, but I think we made it through. And you know, I was thinking Christine the whole time was no matter how bad the technology gets, it's really honestly the information that people tune in for. And so to be able to share that I think is so valuable and so important no matter how many lags or things happen in between.

1:39:14 Oh, thank you, Noah. I appreciate that. I honestly cannot believe how many things go wrong with the technology. But I guess it's just something we just have to roll with the punches, don't we? As long as it as long as we don't lose the connection completely, then well, and yeah, I appreciate the opportunity that I have to be able to pass on some of this information. I mean, none of it's it's not firsthand knowledge from me. It's just really what comes from the ecological literature and what I see farmers doing. I see farmers around the world doing the most amazing things and I really the credit really goes to them. They're out there experimenting with stuff. What would happen if I did this or what would happen if I did that? You know, and then later on 10 years later we go, well, the research shows that when you do this, you know, this is what happens. And yeah, so I'm very privileged actually to have this opportunity to speak to the people who are out there making all these extraordinary changes and credit really goes to them and thank you very much Green Cover for facilitating this process by putting on these webinars and I look forward to talking about nitrogen next week.

1:40:31 Yeah. And it's our honor and privilege to have you as well and also thanks to those that have tuned in. I know that it's we're getting close to planting and there's lots of things to do, but we really appreciate the fact that you guys have tuned in to take part in these as well. So, thank you for that and we will see you all next week. Tatiana says, 'I hope your leg cramps ease up.' So, you have a great rest of your week, Christine, and we'll talk to you on Tuesday.

1:40:56 What did he just say? I hope, oh, the cramp. Yeah, she said, 'I hope your leg cramps are not too bad.' And that they ease up. Yeah. Yeah, they they did ease up, but it was getting to the point there of I was just about to scream, but I didn't. Okay, I don't know what the answer is to that. I've got a rug over my legs and I thought that might stop it from happening. But anyway, who knows? I'm getting old. That's the problem. It's my birthday. My birthday is the problem. My date of birth, I should say. Not my birthday. My date of birth is what's the problem. Yes.

1:41:33 Funny. Sounds good. Thank you so much. We'll see you next week. Yeah. See you. Thanks very much. Green Cover. Bye. And thanks everyone for listening. See you.