Farmers need to release manganese and other metals from soil reserves. Here's how. | Regenerative Ag

John Kempf explains how soil oxidation locks up manganese and iron, making them unavailable to plants. Modern farming practices like tillage and synthetic inputs push soils too far toward oxidation. He recommends cover crops, reduced tillage, and foliar sprays to shift toward reducing conditions that free up these metals.
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Hi friends, welcome to our webinar where we will be speaking about how to release manganese and other metals from existing soil reserves that are in the profile. Over the course of the last couple of years, as I've been learning about reduction, oxidation and the redox environment in the soil, I have been speaking about the need to supply the right oxidation states of manganese and iron. And there have been lots of conversations. The common solution, the typical solution that we would recommend is that immediately what we have observed on many farms and many crops, as we started paying attention to soil redox environments and to plants nutritional profiles, we quickly observed that greater than 90% of all the crops that we work on, when we start using SAP analysis, the SAP analysis quickly reports that the majority of crops are deficient in manganese and deficient in iron. And this is in spite of the soils themselves in many cases having extremely high levels of particularly iron. We know that iron is 4% of the Earth crust. And there isn't really any reason why crops should be deficient in iron. When soil analysis shows that there is excessive levels of iron in the soil, tissue analysis shows that the plants are absorbing excessive levels of iron. And yet from a functional perspective, the crops are actually iron deficient. So the short term solution that we have developed, that we've spoken a lot about, is to begin using foliar applications of iron and manganese to increase the plant photosystem much higher plateau of performance and then over time to improve the soil's availability of manganese and iron so that we are not dependent on foliar applications and don't need to use those for the long term. And so that's what this webinar and this conversation is about is really for us to describe. What are the cultural management practices and what are the things that we can do to increase the release and the availability of the right forms of manganese and iron from the soil profile. So without any further ado, let's jump right into it. When we think about releasing manganese and other elements from the soil profile, the key consideration is that with few exceptions, there are cases when we might be speaking about very sandy soils or soils that because of their geological profile have very low levels of manganese in the soil profile. But they are the exception. The majority of agricultural soils have an abundance of manganese and an abundance of iron and other of these trace mineral metals. And at the same time the majority of plants today are deficient. This wasn't true. I believe from what I can read and the limited data that I'VE looked at and historical observations. I don't believe this true historically. In fact, I would say this has come about fairly recently, only in the past 40 or 50 years. Even the data that I've observed and photos that I've looked at and so forth up through the 70s on a lot of different crops. It appears this is a fairly recent, fairly modern phenomena that is an accumulation of a number of different historical cultural management practices that are going to become obvious as we run through this. The key foundation to understanding these trace mineral metal availability is understanding the redox environment and oxidation reduction. This is an extremely important topic. It's more important for growers and agronomists to understand redox than it is to understand ph. It is a basic, fundamental that everyone should know about and we don't have the time in this conversation to really unwrap and unravel redox in any depth. I'm not going to do that because we've spoken about it many times before in other webinars. And if you want to understand redox, this particular slide is attributed to Olivier Husson and I hosted Olivier on the podcast and also hosted a six hour long webinar where he gave us an incredible, absolutely incredible amount of information on how different redox environments are needed for the expression of different types of fungus, different types of bacteria and different diseases to express themselves. You can find this six hour webinar as course on the Academy at Academy Regen Ag and I would recommend anyone who wants to learn to understand this better go there. It's free. The podcast is free and on the blog I've also linked to several of Olivier's papers and given a brief description overview of the work that he has done, which is really exceptional. You need to go look it up if you're not familiar with it. So the foundational idea we know that in these different redox environments that are reduced or oxidized, we have the different availability of minerals and elements. So these are the influencing factors that will guide soils in either an oxidizing or reducing direction. So when you look at the left side, the oxidizing side, when we till soils and introduce oxygen and aerate the soil, that is going to have an oxidizing effect. And we can think of this oxidizing effect. It's essentially the introduction of oxygen and the impact that it has on the soil. One of those that we understand well is the oxidation of organic matter and releasing it as a gas into the atmosphere as carbon dioxide, CO2. So you think about the chemistry formula for Carbon dioxide. It's E plus two oxygens. That oxygen component gives reference to the oxidation process. So similarly, salt fertilizers have a very strong oxidizing effect, which is why they. This is how they have a damaging impact on soil biology. If you have a salt fertilizer and you dissolve it in water or even as a dry material, you have a cut on your finger and you get it into your finger, it starts burning. That burning is cellular oxidation. It's oxidizing your cells. The exact same thing happens when you apply a salt fertilizer to the soil. And these ions now oxidize microbial cells. So it produces that exact same burning effect to soil biology as it does to our own muscle tissue. Nitrates, because of their presence, they are a strong carrier of oxygen. No. 3. First, they are oxidizers because of their ionic salts, salt fertilizers. Secondly, they also have a very significant oxidation component because of the quantity of oxygen they carry as a part of their chemistry formula. And then the last one on the list, which many people haven't thought very much about, is liquid manure applications, and sometimes also dry manure applications, but particularly any manure source that has high levels of sodium and chloride. So this is fairly common for dairy manure and livestock manure that is fed salt. It's fairly common to have high sodium and chloride concentrations. And this has. This is exacerbated and compounded in a liquid manure pit because of oftentimes other, particularly in a dairy environment, other chemicals, cleaning agents and so forth from the milk house and the parlor being piped into the manure pit as well. So liquid manure and some other sources of dry manure can also have a very strong oxidizing effect. And it's really simple. We know that when we put on some of these manure applications, they have the capacity to kill earthworms. So we try to position our application around rainfall and so forth so that we have a limited impact on soil earthworms. Well, if something is killing earthworms, you can imagine what it's doing to the rest of the soil biology as well. This is. These are materials that have a very strong oxidizing effect. On the other side of the chart, when you have reducing influences, these are when you have saturated soils I did not include. But on the oxidizing side, it would also be when you have very dry soils, both that are extremely dry, with lots of air exchange and airflow and no moisture, are also going to be very oxidized. So desert soils, by and large, tend to be very oxidized and have a very oxidized microbial community. Then the reduced form of nitrogen as ammonium being the inverse of nitrate. And then there are specific plant species going to get into a little bit that have a very strong reducing effect. And from what we are able to deduce, this is a deduction. And we are still gathering the empirical evidence for this. But it appears as though root exudates from most plants that have a functional immune system also have the capacity to be reducing. So this is a very important point, is that plants, some plants that are oxidizing when unhealthy, May have the capacity to be reducing when they become exceptionally healthy. And this is just based on observation and experience. And we're trying to actually get the data to describe what is happening and to what degree. So some of the characteristics of oxidized environments versus reduced environments. We are using the correct terminology of oxidation versus reduction, but we can also use other terms. We can talk about aerobic versus anaerobic, and nitrification versus denitrification and disease enhancing versus disease suppressive. So it's possible to have disease suppressive soils that actively antagonize and shut down the expression of pathogens and that keep the majority of the nitrogen in the soil profile in the form of ammonia. These soils, these reduced soils on the right hand side of the chart Are soils that are always going to be the highest yielding and the highest performing. Now, this comes as a surprise for many people because we've been. When we look at the inclusion of aerobic versus anaerobic, We've been told for many years that really healthy soils need to be aerobic, that we need to have high oxygen content in our soils. There is no evidence in the literature to support this to be the case. In fact, the exact opposite. What soils really need is they need to have good gas exchange. For soils to have good gas exchange and the ability to breathe well, that means that the soils need to be aggregated very well. And when you have aggregate crumb structure, the There is good gas flow and good gas exchange. So perhaps some might define these soils as being aerobic. But when you look at it on a much smaller scale, at the micro scale, and you look inside the crumb structure, these aggregates and these crumbs need to be completely saturated inside the crumb itself. Because the microbial community inside, Particularly the bacterial community in the soil structure, Essentially needs a subaquatic environment. It needs an environment with an abundant level of water. And so inside the aggregate crumb itself, we have an anaerobic environment. When outside the aggregate, we may have an aerobic environment. So it's possible on a microscale to have soils that have both anaerobic and aerobic environments within them at the same time. This is a very important consideration for when we think about the. There's been this conversation that anaerobic soils and anaerobic compost is bad. And the literature and the research actually suggests that we need to have beneficial biology that is not in the aerobic category. And we're going to get into that in a little bit. So when we think about oxidation versus reduction, we're using manganese as an example in this webinar. But this is true for other trace mineral metals such as iron and cobalt and copper as well. Manganese is only bioavailable and physiologically active in plants in the reduced form. So we have the reduced versus oxidized forms. There's multiple oxidation states. You can have a double or triple or quadruple positive in the case of iron. And I think it is important to perhaps create some distinction also with iron, because there is one significant difference that we have observed in the field. Plants do not seem to absorb oxidized manganese. So it's possible to have soils that have high levels of manganese. But on a tissue analysis and on a SAP analysis, the crop is efficient with iron. On the other hand, when you have soils that have high levels of iron, most soils have high levels of oxidized iron and low levels of reduced iron. When they have an abundance of oxidized iron, the plant does actually pick it up, unlike manganese. So it's possible for the plant to have high levels of iron on a tissue analysis, but on a SAP analysis, it will still report as being iron deficient. So this iron is being absorbed by the plant in the oxidized form and is not physiologically active within the plant. It is being stored in vacuoles. And this is very easy to observe experientially, when we have a tissue analysis that shows that we have high iron levels, we can simply test an experiment with putting on a foliar application of the right oxidation state of iron and we get this incredibly strong crop response. So the key point is that we want to. I'm using manganese as an example for this webinar because of manganese critical importance for increasing photosynthesis. I've described this elsewhere many times, but it bears repeating when we think about our entire premise and framework of the work that we do at advancing eco agriculture is all Based on the incredible upward potential that plants have to increase photosynthesis. Most plants that we accept as being common and normal are photosynthesizing somewhere in the neighborhood of 15 to 20% of their inherent photosynthetic efficiency. So what happens if we could increase that to 40% or 60%? We get tremendously increased carbon sequestration and increased yields and increased plant performance. So when we think about the factors as to what is needed to move from 15% to 40% photosynthetic deficiency, what is needed to increase that? The macro kind of big picture perspective pieces that need to be in place are fairly elementary and straightforward. We need to have adequate levels of carbon dioxide, we need to have adequate levels of water, we need to have good chlorophyll concentrations within the plant, and we need to have sunlight. Those are the big four, right? Everybody knows that we need those four elements, but there's a fifth, and it's the only nutrient that bears mentioning on its own as a standalone, and that is manganese. The reason manganese is so important is because during the photosynthesis process, when water is absorbed either from the atmosphere or from the soil, the first step in the photosynthesis process is that the water molecule needs to be split into hydrogen and hydroxyl ions H and OH. So we go from H2O to H and OH. And this process of splitting the water molecule is referred to as water hydrolysis. And the enzymes, the metalloprotein enzymes, that are required to facilitate this process need manganese as the enzyme cofactor. And thus, because many plants are manganese deficient, manganese actually in many crops is the limiting factor that photosynthesis. So this is why in our work, in many cases, we have observed manganese to have significant impacts on increasing yield and increasing disease resistance, because it's so foundational and so fundamental to increasing photosynthesis, and it's so commonly deficient. So that's the reason and the context for why we're focusing on manganese in the course of this conversation and using it as the framework. So where we stand today, compared to the 1970s and even earlier in some environments, is that many agricultural soils are excessively oxidized because of historical cultural management practices because of tillage, which has an oxidizing effect. So I want to speak a little bit about this whole conversation of aerobic versus anaerobic biology and bacteria in the context of a redox environment. So this redox graph and chart that you see in the background is from Olivier Husson that I referred to earlier. And then we placed these different groups of organisms, these bubbles that represent these different groups of organisms on this chart. And I just want to be very clear and upfront that these are not perfectly precisely placed. We just put them on here as an illustration to make the point. The way this chart works is if you go towards the upper right, you have a more oxidized environment. As you move to the lower left, you have a more reduced environment. In the context of speaking about bacteria and soil biology, it's very common historically to have this conversation about aerobic versus anaerobic, black and white, good versus bad. That's not rid of the conversation at all. As you can see on the chart, reduction versus oxidation occurs on a spectrum. Aerobic versus anaerobic occurs on a spectrum. It's not two opposite polaris. And the important piece is so aerobic bacteria on the upper right side of the chart, when they are dominant in a soil environment, when they are in close proximity to manganese and iron and so forth, and they absorb some of this manganese and iron, use it for their own mobile cells, transfer it back into the environment, this total microbial interaction has the net effect of having an oxidizing effect. So you may hear us refer to oxidizing bacteria versus reducing bacteria. And that is another way of talking about anaerobic bacteria versus aerobic bacteria. The aerobic bacteria tend to have an oxidizing effect and limit the availability of manganese and iron and other trace mineral metals in the soil profile. Also, these aerobic bacteria on the upper right side of the chart are the disease enhancing bacteria. In other words, they make diseases worse. In fact, many pathogens are in this group. Fusarium verticillium, Phytophthora pythium, and so forth. Many of these, there are exceptions, but many of these organisms are in this aerobic group that they are oxidizers and they are dependent. I actually posted a blog post on this a couple of weeks ago, a quote from Don Huber. They are dependent on the presence of oxidized manganese and that the capacity to convert the manganese in the plant root system to the oxidized form in order to create an infection without changing the manganese to the oxidized form, they can't produce an infection. So many of our pathogens and many of our diseases are in this aerobic group. And then there are also some diseases and some pathogens that are on the opposite end of the spectrum. They're in the anaerobic group at the lower left side. Now, here's the interesting part, there are these two groups in the middle that we often don't hear very much about. The facultative aerobic and the facultative anaerobic groups. The term facultative in plain English means simply that these organisms can thrive in both slightly aerobic and slightly anaerobic environments. They have a preference for one, but they can survive in both environments. And interestingly enough, it is these two groups in the center that have our disease suppressive organisms. These are the organisms that suppress the activity of the two groups on the opposite ends, on the polar ends of the spectrum, the aerobic and the anaerobic groups. It is also these facultative aerobic and facultative anaerobic environments that are. They're disease suppressive. And they convert, particularly the facultative anaerobic organisms. They convert manganese and iron and so forth. They use the electrons from manganese and iron and metals and soil profile, and they convert them to the reduced form. So when we have these groups of organisms in the soil, it increases significantly our availability of manganese and iron. So here are some examples of cultural management practices that we can use to shift soils into the reduced state and away from the oxidation. So the key point here is that it is not that oxidation is bad. All of our soils are fluctuating all the time. If we have drought conditions, they're going to move into an oxidized state. That's okay. That's not a problem. Some soils, because of the climate and the environment, if you have some desert soils, they're going to be dominantly oxidized. It's not that oxidation in itself is a problem. We need to have some oxidation in our soils. We need to have good gas exchange. We need to have oxygen flowing to the soil profile. The problem has been that historically, because of our historical cultural management practices, we have moved the spectrum. Our soils are supposed to fluctuate. They're supposed to, in the case of a drought environment, they're supposed to move in the deoxidized direction. And then when they become saturated, they're supposed to move back into the reduced direction. They're supposed to fluctuate back and forth. And the soil has the capacity to suffer this fluctuation and to slow down the fluctuation. Otherwise it'd be a very wobbly number and move back and forth very quickly. Healthy soils have the capacity to slow this down. So when we talk about physical, there's a discussion around ph buffering. What is the soil's buffering capacity? To buffer rapid ph transitions. In the case of redox, the scientifically correct term is poising. We talk about redox poising, which is same thing. It's the soil's capacity to buffer these rapid oxidation swings back and forth. The problem is not that our soils are occasionally oxidized. The problem is that the accumulation of all the things that we have done with tillage and salt, fertilizers and limestone applications is we have moved our soils in the direction of being dominantly oxidized, and they're not swinging back in the direction of being reduced. So for us as farm managers, our task is to swing the soils back in the direction of being reduced and to facilitate that fluctuation back, to facilitate that pendulum swinging back in that direction. When we can do that now, we can increase our trace mineral availability and have the yield increase and the quality and disease and insect resistance increase. That corresponds to the increase in those disease suppressive organisms and the increased manganese and iron availability. So here are some examples of cultural management practices to shift soils back in this direction. The obvious one is reducing tillage and aeration in some context. In some cropping environments, this isn't possible, but it is possible in many more environments than people realize and think. This is the one very significant piece that we need to some soils need to be aerated. Most soils, most agricultural soils today are over aerated, and we need to manage that. So if we can reduce tillage and aeration, that's going to reduce the oxidizing impact. Covering soils is an obvious one. But actually covering soils with green photosynthesizing plants, this is one of the foundational principles of regenerative agriculture systems. Here's an interesting tidbit. When we think about redox environments in the agricultural ecosystems, one of the most powerful reducing processes known in biological systems, as far as I am aware, is photosynthesis. Photosynthesis is a very powerful reducing biochemical reaction that occurs within the plant. And when we have abundant photosynthesis occurring, then that has the effect of reducing our soil environment in the long term. So this is just a different perspective and a different angle of saying that we need to have our soils covered with green growing plants every day, that the sun is shining and the temperature is high enough to have photosynthesis, we should never have bare soils and exposed soil. Crop rotations are another obvious fit, particularly crop rotations with some of the more reduced crops and then reducing crops and cover crops. And I have provided this in other webinars, already, I'm not sure that we have it here, we don't have it here. So I'll give you a quick rundown. There are many plants that we don't know the impact that they have on soil biology when they are unhealthy. We suspect that when they are extremely healthy and are completely resistant to disease in insects, they can move in the direction of having a reducing impact because of the different types of secondary metabolites that they produce and send out through the root system. But some crops that we know to have a reducing effect, a very pronounced reducing effect, even when they're not an optimal level of health, are oats pretty much at the top of the list. Buckwheat, alfalfa. Not just alfalfa. But my understanding is that the majority of the legumes, forage legumes, clovers, alfalfa and so forth, brassicas and non GMO corn, those are the. That's the very short list of crops and cover crops that we know to have a reducing effect even when they are not at an optimal level of health. GMO corn has an oxidizing effect. Wheat has a very strong oxidizing effect, at least modern wheat varieties do. And we suspect that rye is fairly neutral, maybe slightly on the oxidizing side. So the bottom line is that of those crops that I mentioned on the reducing side, the oats and buckwheat and alfalfa and forage legumes, we want to have as many in the brassicas, we want to have as many of those in our cover crop mixes in our crop rotation as possible. To have this to move the pendulum in the direction of the reduced soil environment, obviously keeping soils moist, which again, comes back to keeping soils covered. And in the context where irrigation is important, this can actually be a very useful disease control strategy. All of these, remember that I said that Fusarium and Rhizobium. Excuse me, not Rhizobium, rhizoctonia. Some of these organisms are dependent on oxidizing manganese in the root profile in order to cause an infection. Guess what? They can't do that when the soil is wet. So if you're growing a watermelon that has a Fusarium susceptibility, just simply making sure that you have abundant irrigation and keeping the soil wet in the row can shut down the Fusarium problem. Obvious one is avoid salt, fertilizer, nitrate and limestone applications. I didn't mention this earlier, but limestone containing carbonates and oxygen in the carbonate form actually has a significant oxidizing effect. So only apply limestone when you need calcium and not based on ph. That can be a whole other conversation in and of itself. And then a factor that can have a significant reducing impact, of course, is foliar applications that increase photosynthesis. Because as I mentioned earlier, photosynthesis has this very strong, it is very strong reducing biochemical process and has a very strong reducing effect on soil biology. And when you any foliar application that increases the plant's photosynthesis can have that effect and have that response in the short term, what we've observed is that manganese and iron availability can increase very rapidly when we incorporate these management practices. If we include, if we add a cover crop, let's say we had a cover crop of oats, we expect to see increased manganese absorption in the crop immediately after the oats, which is why corn crops raised after oats are known to be higher yielding or soybeans after oats are known to be significantly higher yielding and more disease resistance. It's because of the increased means availability that the oats provide, in addition to all the other benefits of course, that cover crops have. But manganese specifically has a significant impact here until you get to that point where soils are increasing the manganese and iron supply. In my professional opinion, what I have observed is that it is a complete total waste of money to apply manganese and iron to the soil and expect it to fix the problem. It does not work. When I say it does not work, I mean that there is no increased crop absorption of manganese and iron from the soil. Because whatever it is that you apply, as long as the soil environment remains oxidized, whatever you apply immediately gets converted to the oxidized form and the plants don't absorb it. So in the short term, the immediate solution for increasing a crops photosynthesis is to supply the manganese and iron until the soil is releasing it as a foliar spray. You need to spoon feed it and oh my goodness, it is so worth it. Very often farmers say that, well, I don't want to, I'm not set up to foliar feed my crop. Are you spraying herbicides and fungicides and insecticides? Then you can figure out how to foliar feed your crop. And the economic rewards are significant because I described how significant manganese is to the photosynthesis process. Over and over again we can see significant yield and quality increases from manganese and iron applications. It's a very significant ROI application. So what we have observed is that shifting soils to a more balanced redox level and moving that pendulum Back in the reduced direction a little bit can increase manganese and iron availability to the plant as measured by crop absorption from 1x to 40x. Now that's obviously a huge variability. And you look at that, you say, well, 1x if you just increase manganese availability by 100%, how significant is that? It's actually very significant. If you have soils here in the American Midwest, in the Corn belt where we have soils, if you have only, let's say 2 ounces of reduced manganese in the soil profile on a per acre basis and you increase that to 4 ounces of available manganese, you're going to have a significant impact on yield and a significant impact on disease resistance. So a 1x increase can be huge and you can also have as much as a 40x increase. And that of course, for that to happen. Everything in agriculture is context dependent. You can have 40x increases on soils that have extremely low manganese to begin with, or on soils that have a high manganese profile. So there are different. There's obviously a lot of variables in play. The bottom line though is that you can supply 100% of a crops manganese and iron requirements simply by releasing what is in the soil profile. When you get the biology and the redox environment functioning correctly. Of course, I've described some of the effects of manganese and iron. I haven't really gone into detail on iron, but these are two of the trace mineral nutrients that have some of the most significant impacts on yield disease resistance. Now that statement that I just made is an interesting statement. When you look at the mainstream agricultural landscape. The two trace minerals that are the most widely used in broad acre crop production are boron and zinc. It's very common for growers to apply zinc in the furrow as a starter at planting, but they don't apply manganese in the furrow as a starter. They don't apply iron. Why not? When I started looking at this and understanding the redox environment, all of a sudden it becomes really clear. The reason that zinc has become a mainstay and has become more mainstream is because it doesn't experience these redox shift. Zinc is not present in the soil in different oxidation states, so there is no reduced versus oxidation shift. Zinc is always available in the soil in the double positive form, so it is always plant available. And I believe the reason commercial production agriculture has not observed the manganese and iron yield responses that manganese and iron are capable of delivering is because they are applying products into the wrong environment, into an oxidized environment and then they immediately become oxidized and the plants benefit from them. So it's not that the product isn't effective, it's that it was applied to the soil and the soil immediately oxidized it and the plants did not benefit from it in any way. And it's really interesting because when we do SAP analysis and we balance the trace mineral levels, yes, zinc is important. It gives us increased leaf size and so forth, increased photosynth capacity, but not to the degree that iron and manganese do. Iron and manganese also have a very significant influence on photosynthesis and overall crop performance, and they are underrated and misunderstood because they have historically been applied in the wrong context and in the wrong form. So if you want to dig more deeply into understanding the redox environments, I would highly recommend taking this course on the Academy. You can see the URL above Academy Regen Ag and I highly, highly recommend it. And if you want to have other There are many more dots that I was able to connect here, of course, than just in an hour plus long webinar. I also would encourage you to buy my new book that just released on Wednesday of this week. And in this book I posted some of the excerpts on the blog as well. But there are many more dots to connect regarding redox environments, disease suppressive soils and increased yield. The reality is that all of these pieces fit together very beautifully. It becomes a beautiful mosaic and a beautiful picture that when we have reduced environments, we have increased manganese availability and increased yields and increased disease resistance. Those pieces all fit together into the same profile. And unfortunately it's not the profile that is present in our mainstream agriculture, but it's a profile that we can easily create in our soils with our cultural management practices. So those are the thoughts that I wanted to share. I'm going to switch to Q and A and I invite you to share your questions, which many of you have already. So here's a first question from Ruben Palma. Will ammonium nutrition interfere with calcium and other cations? What source of silicon would be best? All right, two different questions. The first one Will ammonia nutrition interfere with calcium and other cations? It's not my understanding that it will. You want plants to absorb nitrogen, preferably in the form of amino acids, second best, azurea, third as ammonium and definitely not as nitrate and ammonium. Applications to the soil have the effect of increasing calcium solubility and calcium availability because they displace calcium from the soil colloid structure and the cation exchange sites. So in that sense it can actually increase Calcium nutrition temporarily of a plant. And then to your second question. What sources of silicon would be best? Well, in this profile the best source of silicon is abundant microbial activity. There is a direct correlation between microbial activity and silicon absorption by plants. In fact, we can use it as an analog indicator when we are using our SAP analysis. The plants with the highest silicon levels are those that have the greatest microbial activity. If you want to, for immediate short term application in disease environments, for disease suppression and so forth, or insect suppression, which silicon is both very effective at, I would suggest foliar applications. Potassium silicate by itself because it's a very difficult material that doesn't like to mix with anything else. Gary, nicely with a confounding question. Hi Gary, it seems to me that we have a conflict in our assumptions here. Why would liquid manure, which is fermented not be highly reduced due to anaerobic fermentation? Ah, Gary, good catch. So the answer is that liquid fermented manure, if it is truly fermented, will be reduced and it should be reduced. But much liquid manure today isn't actually fermented. It doesn't have good biological activity. That's why it crusts and why you have a sludge at the bottom, because all the biological activity has been shut down and because it has a high salt content. So you have something that it is anaerobic biologically, but it's also biologically mostly dead. There is very little microbial activity that's actually happening in these dead manure pits because the salt content is too high. And so it's the high salt content that actually ends up having the oxidizing effect on the microbial community. It's a very good question. Thanks, Gary. Question from Eric George. Hi Eric. You said that iron will show up very high on a soil test, including both the oxidized and reduced form in that soil analysis. Is this the case too for manganese for common soil analysis, Logan, etc. In other words, do manganese soil results generally represent the total pool in a similar way to how the iron results represents the total soil pool? Eric, this is a good question and I would say that the short answer, I'm not a soil biochemist and I don't know the exact answer. There would be people that would be able to give a very detailed and precise answer from an experiential perspective. What we have observed is that there is no correlation between the manganese levels in a soil and actual on a soil test and manganese absorption by the crop. So it does seem within that context that a soil analysis will also pick up the oxidized manganese. And there are other. Yeah, we have to consider the oxidized environment and other pieces as well. But the short answer is yes. I think it is possible for soils to have high manganese levels and yet for the crop itself to have poor manganese absorption. And I would also clarify that I wouldn't Describe a typical melic 3 or ammonium acetate soil extraction as representing the total pool of either manganese or iron. Because if you were to conduct a mining assay at a laboratory such as Agent Labs or Acme Labs, you'll quickly see that many soils will have hundreds or thousands of pounds of manganese and iron in the top six inches. So it's a very significant pool. Question from Jan what is the fate of manganese in plant tissue? Does it wear off after hydrolysis? So we have to apply it regularly when soils cannot. Where does it go? It's a good question, Jeanne. The manganese that is used in. I shouldn't actually say used, but that is necessary for the water hydrolysis process is essential as an enzyme cofactor for a specific enzyme so that manganese doesn't get used up per se. It just repeats that same process over and over and over again. So it's not that we have to apply it constantly, but it is true that the crop does need a constant supply every day through the growing season that the soil should be capable of delivering. Gary, nicely asked a follow up question. I asked this question because I've been specifically trying to work out cost effective method to ferment manures and compost to move the soil towards a more reduced state. Gary, this is something that I'm just learning about and want to dig into more deeply. But I would suggest you look at some of the work being done in producing what is called bokashi B O K A S H I and it is essentially fermented compost or silage, basically ensiled compost instead of the typical aerobic composting process. And I haven't dug into it deeply enough yet, but my first exposure to it has me quite excited about the possibilities of having something that we capture more of the organic matter and organic material. Don't oxidize it off as carbon dioxide into the atmosphere and have it in the reduced state. There's some very interesting work being done in this area. Question from Dan. I fog nutrients onto my crop. I use manganese salt to the fogger. Is the addition of glycine beneficial or should be using a more powerful chelator. Glycine may be beneficial, but it's not strong enough as a chelation agent. And manganese sulfate is also not the right form. So manganese sulfate, if you look at the chemistry formula, so four, we have the presence of four oxygen atoms. And that is an indicator that this form of manganese is oxidized. As though that were not enough when you foliar it onto the crop leaf surface. When that droplet dries out on the leaf surface, the manganese becomes exposed to oxygen in the air and it oxidizes again. So you need to use a material that is first converted to the reduced state in a solution and then chelated in the reduced form. Have you ever seen a farmer dual plant corn planted in alfalfa pull river between the hemp rows? Yes, absolutely. It's certainly not yet a common practice, but becoming common much more rapidly and I think it's valuable and necessary and important. Diversity is always a positive question from Steve Darcy. What would be an example of a soil or soil conditions that would be a candidate for aeration? The simple answer I would suggest is soil that does not allow good water infiltration. Because when you don't have good water infiltration, of course you're also not going to have good air exchange. So we care about both gas exchange and water infiltration. And there are many wells that don't have either of those. Now there are a lot of people who have pronounced opinions about tillage being a universal negative. However, I'm not quite in alignment with that. And I believe that there are many soils that would benefit from aeration to get the soil development process started. If soils are so compacted that they don't have good water infiltration, don't have good air infiltration. There are some soils that need aeration to kick start the process, but also should not be a tool that is needed for the long term. Either question from Frank. I grow alfalfa with subsurface drip irrigation. The drip tape is 10 inches below the surface. So near a lot of roots. I inject atmospheric oxygen into the water. I've seen tremendous crop response. I've seen increased endogium nodules on roots and increased lead size, increased root growth. Is it a mistake to inject oxygen into the water? Well, Frank, obviously you're getting positive responses. And so I would say the answer is if you're getting a positive response, then it's probably not a mistake. It is a positive in the environments where it might be a mistake. And we have observed Context again, agriculture is so context dependent. We were working with a pepper grower so had subsurface drip irrigation who had severe problems with Fusarium and Phytophthora and they were injecting hydrogen peroxide into the drip tape and supposedly to treat the Fusarium and the Phytophthora and it made the problem significantly worse because it's an octodizer. So if you're not dealing with any of those specific organism challenges, and remember that alfalfa itself as meant has a very strong reducing effect. So the slight oxidation that you're adding from injecting oxygen is being balanced out with other things in the ecosystem. So it's not that any of these things are necessarily universal negative or universal positive. It all depends on the context in which they're applied. Question from Greg Stack phosphate fertilizer for great foliar application is often available in the form of P2.05. Wouldn't this be highly oxidative for the plant for foliar application? Or would this concept only apply if soil applied? Yes, Greg, your assumption is correct. This conversation around redox environments. There is also a conversation that is worth having about the redox environments on a plant lead surface, but that's a separate discussion for P2O5 applications to soil. It's really the soil context and soil environment that we're focusing on. So adding P2O5 to the leaps is not a significant concern. Question from Darren Petzer. Hi Darren. Compared to oxidizing fertilizer inputs, how oxidizing is high bicarbonate in irrigation water? The answer is vary and there's. You can do the math on what it is, but essentially what you want to measure is the quantity of oxygen that you're applying as bicarbonate versus compared to the quantity of oxygen you're adding in the form of nitrate. And that is not a complete metric by itself. You also need to calculate. You can do the math on the quantity of electrons from various ions and so forth. The bottom line is that when you have abundant levels of bicarbonates and irrigation water, it's probably a bigger impact than fertilizer applications. Question from Ido Aviani. Hi ido, what is the effect of redox on phosphorus availability? So it does have an effect. Not as significant as biology, because soil biology is really should be the facilitator of phosphorus absorption. But all of the macronutrient anions, phosphorus and sulfur and nitrogen have very wide redox swings. So they can go in the case of nitrogen, for example, from a negative 4 to a positive 4 all the way from ammonium to nitrate. Then you have nitrites and so forth. And with sulfur you have sulfides and sulfides and sulfates, etc. With phosphorus you have phosphides and phosphates and phosphates and so forth. So you have these significant oxidation or redox swings. And from a chemistry perspective, they are most available at one of these given oxidation states. But in a biological system, we want the plant to absorb these nutrients mediated through biology. So we want biological delivery rather than ionic delivery. And that changes the redox conversation in the context of nutrient delivery a little bit. Question from William Truncale. How does growing crops on plastic affect gas exchange? William, this is an awesome question, one that I've thought a lot about and I don't have a good answer for. I don't know that anyone has measured it specifically, but what we have observed orientally, what many growers observe, is that they can produce abundant microbial communities underneath plastic. They don't seem to suffer from what we would perceive to be limited gas exchange. Now let me qualify that answer. That is, when we are talking about growing crops on plastic and banded plastic strips that are three to five feet wide, we have observed significant negative effects. When we have area wide plastic, like in a greenhouse where we have 30 foot wide plastic and plants only growing up tables, that is certainly a problem and limits carbon dioxide. We've observed that many times over and also limits biology. But in plastic strips, for whatever reason, I don't fully understand why or how. I don't know that anyone has measured it. But there seems to be a net positive instead of a net negative. Question from Ann Marie. Oats and buckwheat between row cover crops for perennials such as grapes mowing at cover maturity, will that provide the same benefit as for an annual such as corn which is planted in rotation? The answer is yes, it will, because the effect is happening from the soil microbial population in the root system. It's not from the benefit of the oats cover crop or buckwheat cover crop being incorporated. It is just a function of what these cover crops do in their root system and the types of biology that they have a symbiotic relationship with. So the biology that has a symbiotic relationship with the oat plant or the buckwheat plant has a very strong reducing effect. We were taught that boron in the furrow is really bad, antagonistically affects germination. Is this true? Only for a very few crops that are boron Additives such as green beans would be a case in point for most crops. It's not necessarily true as long as you apply very small quantities. If you apply if you have a calcium deficient soil and if you apply too much, then it can have a negative effect, but it's not necessarily true. We apply boron in the furrow routinely on the majority of the farms that we work with. Question from James. How is redox measured in the soil? You can purchase $90 instruments called ORP meters, which stands for oxidation reduction potential. You can measure it very simply, but you shouldn't because it doesn't matter. That may seem strange given everything that I've just talked about, but the reason you shouldn't and the reason it doesn't matter is because it's like trying to measure a leaf falling from a tree. It's wobbling back and forth all the time. You get an inch of rain, it's going to show being very reduced. It dries out. It shows up being very oxidized. It's not the number that we care about so much as we care about the microbial population. Is the microbial population a reducing microbial population that is disease suppressive or is it an oxidizing microbial population that is disease enhancing? So it's really the biology that we care about more than the chemistry number. Are humic and fulvic acid good chelators for manganese? Yes they are. And for minerals in general. Dan says I'm halfway through your book. Very informative. Well Dan, considering that it came out three days ago, that's quite an accomplishment. Thank you. I can only assume you must consider it interesting more. Congratulations on the book. Thank you guys. I appreciate that plants that you found to have an oxidizing effect also perform photosynthesis. So what is the oxidizing effect in the rhizosphere? This is a very question, Jen. So I would refer you if you want to dig into this a bit more deeply. I published a blog post on the effect that oats have as a reducer and why they have this effect that describes this a little bit. But it seems to me from my understanding, what I've learned so far is that the determining factor that determines whether plants have a reducing effect or an oxidizing effect is determined by the quality and type of compounds that are sent out through their root system as root exudates. So if you have a plant that is unhealthy or that has suffered from short sighted breeding and it transmits mostly soluble sugars and simple sugars and very few complex compounds, phytoaloxins and secondary metabolites and so forth. It seems that these plants have a very oxidizing effect. Modern wheat is a great case in point. Crops that have a reducing effect tend to transmit much more complex carbohydrates and a much higher concentration of phytoalaxins and immune compounds. So in my understanding today, to the degree that I've connected the dots so far, this seems to be the common thread of plants that have an oxidizing effect versus effect is the types and the quality of the compounds they send out through their root system. Question from Philip Charlotte hi John. How do we measure soil aggregation? How do we know when we have enough? I would suggest that you measure your water infiltration rates and it's a little bit like organic matter. Do you ever have enough organic matter? Never have enough water infiltration rate? When you can infiltrate 9 inches of rain per hour, then you probably have enough. I don't think you'll ever have too much. Question from David do you know if increasing fungal species and levels help with the soil release of manganese and iron? The answer is absolutely yes. I've framed this conversation in the context of bacteria, but there's obviously a very close interplay between bacteria and fungi and all these pieces connect together. Question from Jessica how often do you foliar feed manganese and iron? The answer is as often as the crop needs it and it's economically justifiable. On high value fruit, nut and vegetable crops we foliar feed manganese and iron every 10 to 14 days or until we fool your feed every 10 to 14 days until the plant SAP analysis shows that we have enough. And that can occur as quickly as two to three months or in some very challenged and compromised ecosystems. It can take a year or two. On broad acre crops, we're often doing several applications per season. Question from Steve Tucker what is the best form of manganese and iron? Foliar feed fertilizer. The answer to that is really, really easy. It's advancing eco agriculture's rebound. Manganese and iron. We don't do these webinars as infomercials to just talk about products. But it would be remiss of me not to describe that our entire rebound line of trace minerals was developed to address this exact challenge. So they are all in the very reduced form. They're first converted to the reduced form. So when you look at the list of ingredients, the list of ingredients is probably going to say manganese sulfate and copper sulfate. And so Forth, So that is the raw material, but it is then converted to the reduced form. And once it's reduced, it is chelated in the reduced form so that they are extremely plant available and stable. Question from Chris Newman. How does putting in drain tile benefit the oxidized reduce ratio? And would money be better spent putting in reducing cover crops instead of a large investment in tile? Again, Chris, the right answer is dependent on context. But I would say that in today's agricultural ecosystem and landscape, we need to develop soils and ecosystems that are extremely climate resilient, because we are now we should expect to get several 3 to 5 inches of rainfall per year events. Our soils need the capacity to handle that. So they need water storage capacity and water infiltration capacity. So there are a number of growers that we work with who have soils that have the infiltration capacity of three inches an hour. So it's possible to develop very rapid infiltration rates, to not have any water runoff and to then also develop that very deeply so that you have good percolation down into the soil profile very deep and have a lot of water storage capacity. So for some soils, in some contexts that's enough and didn't need to invest in tile. For other soils where the water table is two feet deep and you don't have the capacity to develop this water storage capacity, you may need drain tile. So that's again the context dependent question. There's a question from Sergio. Hi, Sergio. If I apply manganese sulfate and iron sulfate at the beginning of the process, would it work in the soil when I apply compost? We've done this experiment actually, and we have experimented with manganese application into compost and then applied to soil at increasing rates, starting at 10 pounds of manganese sulfate per acre, all the way up to 400 pounds of manganese sulfate per acre. And the context is important again. So the context was that these were applied onto typical agricultural soils that were. We didn't measure them, so didn't measure the soil biology. But I'm confident they were oxidized because they were being tilled almost every year, a few cases several times per year. And we got zero increase in plant absorption of manganese in the plant. The manganese levels on the soil analysis went up, but the MANG levels on the SAP analysis did not change. And this was on a number of different vegetable crops that we've tried this on in Eastern Pennsylvania. So I think it's possible for. This is why I made the comment earlier that in general, I believe that applying manganese and applying Iron to the soil is largely a waste of money until we first change the soil profile. We first have to have the soils be primarily reduced and not oxidized. And then if they are needed, then it can be worthwhile to apply manganese and iron to the soil. Follow up question from Nick. He says that I have increased my manganese levels in my soil test from logan labs from 16 to 26 part per million through ground application of manganese sulfate. You said that this is a waste of money, but wouldn't this be beneficial when combined with reducing cover crops to make it available? The answer is yes, it would be beneficial when combined with reducing cover crops. And it's entirely possible that if you planted reducing cover crops, your levels would have increased from 16 to 50 parts per million by themselves without any application. So here's the key point. That many soils have reserves of manganese and iron to the tune of hundreds of pounds per acre. That these reducing cover crops and biology can tap into and release that don't show up on a soil test on a Malic 3 or ammonia mass extraction. So it's not necessarily a waste of money. Maybe your soil needed it and maybe it didn't. So try the reducing cover crops first and then apply the manganese sulfate later if you need it. Question from catalyn on the molars chart, manganese is antagonistic to iron. Should we apply them separately? In which order? You do not need to apply them separately as a foliar when they are in the chelated form, because in the chelated form they don't antagonize each other in the solution or within the plant and also within the soil. Again, it's biologically mediated. And the molars chart in the soil is dependent on chemistry interactions which we don't want to have happening in our soils. We want to have biologically mediated interaction. A question. This is from Francisco. Hi Francisco. One of the biggest problems of reforming soils is compaction. Usually this is connected with the assumption of anaerobic connection. Can you explain how this fits with benefit of an anaerobic reduced condition for soil biology? So I'll just reiterate that once more, try to make it as simple as possible.
We want soils that have good gas exchange and good water infiltration. And at the local micro aggregate level, when we have these tiny aggregates, we want the interior of that aggregate to be saturated all the time. So this aggregate, which is where the majority of the biology is going to be anaerobic, while the bulk soil could be considered aerobic. So again, we need A balance. We need both of these things present in soils at the same time. Question from Chris Newman. If putting manganese or iron on at planting like in the furrow, would there be any benefit to slowing down the oxidizing of these elements if it were to be combined with a humic substance, or will the soil oxidize it just the same? The stance is that when these materials are chelated, that slows down the oxidation process. And the degree that it slows it down to depends on the degree and the microbial interactions with the chelation agents. So if you look at our rebound products, we use humic and fulvic substances in our rebound products because of the impact they have with soil biology. So it's absolutely possible to apply these materials that are chelated with humic substances in the furrow and get a very nice crop response. Question from Kyle, as an apple grower from Michigan, what is the risk of phytotoxicity or fruit burn with these essential metals? How should we adjust timing of foliar sprays if humidity is much higher at night? So the first answer is that if you have a properly designed foliar material, there should be no concerns about phytotoxicity. You would have to over apply by, I don't know how much, 10x or 20x at least, in order to have concerns about phytotoxicity. And the key for effective foliar treatments is you want the droplet to remain liquid on the leaf surface as long as possible. So you should spray in the evening so that when you have high humidity at night, it remains liquid on a leaf surface all the way until the next morning. Here's a good one from Jason. How many years do you think that glyphosate residues in soil have accumulating effect on manganese? What's the best way to deal with these residues? 14 years since last use in an orchard situation. This is a good question, Jason. It's an important one to address because what we have learned over the last decade or longer is that glyphosate residues have a chelating effect, but they have another effect as well that is even perhaps more damaging and more powerful than the chelating effect. And that is that they actively support, suppress and antagonize all of our disease suppressive organisms and they enhance our disease enhancing organisms or said, in other words, they enhance the oxidizing organisms. So it's actually very common. When you think about 8 ounces of glyphosate and applied on an acre, the quantity of manganese that it is. Chelating is significant, but not insurmountable. But the bigger impact that it has is that it actually suppresses. It actually converts the microbial population to be primarily oxidizing, and it shifts all the rest, even the manganese that it did not oxidized, it can shift the majority of the remaining manganese in the soil profile to the oxidized form. So this is actually a bigger impact than just the chelation impact itself. And how long does that last? Well, I believe it lasts until a significant part of that glyphosate is bioremediated and taken out of the system. And we've been in the process of developing some products to facilitate this process of bioremediation. But. We know that it can last for years, and in many soils it's lasting for decades. It can also turn around very quickly. When it does seem that when we grow cover crops and facilitate this reduced environment and we speed up and we increase the soil population of reducing organisms, that also seems to speed up the bioremediation of glyphosate ore. I shouldn't really say that because we have a hard time getting data to actually measure that and validate it. But we do know that we get dramatically increased manganese availability and the system seems to really turn around even when we have historical glyphosate residues. So maybe that's the best way to answer the question. So I want to thank all of you for your questions and your interaction. I've really enjoyed it, and there's many more questions that I could get to. But we're 20 minutes after the hour and I want to be considerate of all of your time and attention. So I want to thank you for being here all the way through to the end. Please check out my book, check out my blog if you want further information, and I look forward to being in touch and seeing you again on more webinars in the future.
Happy growing.
Thanks, everyone.
Bye.
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