John Kempf -- Simple & Comprehensive Fertility Management for Market Gardens

Sam. All right.

Welcome to our third presentation in the 10th annual Soil and Nutrition Conference. John Kemp is our honored speaker. I'd like to refer.

I am honored.

Hi, John.

Hi, Dan.

Haven't given you a noogie since you got married and had kids, so.

Might as well begin now.

I'm honored to have you here, John, and speaking to a topic that is, I think, very relevant to many people, which is how do we use a small piece of land most?

Well, yeah, it is. That is an interesting topic and it's one that I've actually spent a lot, an inordinate amount of time thinking about this presentation and preparing for it, because I'm reminded, I forget who originally said this. It might have been Churchill, it might have been someone else, but something along the lines of, if you need me to present for three hours, I'm ready right now. You need to present for 30 minutes, I need a week to prepare, and if you need me to present for five minutes, then I need a month to prepare. And this is a little bit like that, in that the question that you asked me in the conversations we've had is how can we manage with these principles of soil biological management and how can we implement them on a smaller scale as simply and as effectively as possible? In other words, make it as simple as possible, but no simpler, and gelling it down like that has required quite a bit of thought.

So go for it.

All right, thank you, Dan. Hi, everyone. Thanks, Dan. So, in thinking about this topic, I just described for Dan how it's been interesting in the need to really gel things down and what does it really mean to have biological soil management be as simple as it possibly can be, no simpler. And so I put some thoughts together around my perspective and my understanding of that today and I'm just going to jump right into the slide deck. I anticipate my presentation is going to be shorter than the full hour that you might be expecting. I'm not sure how long it'll last, but probably more likely in the 30 to 45 minute range. So if you have any questions through the presentation, just feel free to ask away. And we're going to have lots of time for interactions, which I really enjoy, and lots of time for questions. So with that, I'm going to jump to the screen share and kick things off. Zoom has this annoying characteristic where it always blocks the present button here. Just need to get the keystroke commands. Alright, so when we think about developing systems to manage plant nutrition and to regenerate soil health, the context around this Presentation specifically is how can we develop these regenerative agriculture ecosystems that we've talked about? How can we develop ecosystems that regenerate soil health, that regenerate plant health and give us complete resistance to diseases and insects, and of course, ultimately also regenerate public health and grow such nutritious food that we can really talk about growing food as medicine. So how do we implement these types of systems on a smaller scale, market garden scale, where we might have 40 or 50 different crops in a half acre or on five acres and take into consideration all of the different plants nutritional requirements, and where we don't really have the scale to use the tools such as SAP analysis that we use on our large scale commercial crops. So it's really been an answer to that question of how can we take the systems and the process that we have learned and bring them down to a smaller scale so that they're universally accessible across the board or universally applicable across the board for all different types of crops? That's a bit of a challenge. I thought, as I described, I thought a lot about this and I think the foundational framing for, for us, for this type of approach to be successful, it can only be successful when plants primarily get their nutrition from biology. And in previous presentations I've used the term biology supersedes chemistry. And what I intended to communicate with that phrase is that you can have soil with perfect chemistry, the mineral nutrition on a soil analysis is perfectly balanced, and yet you can still not grow healthy plants on that soil as long as you have poor biology. So chemistry alone, without biology does not grow healthy crops. And this is one of the fundamental failings of hydroponic production. However, the reverse is very possible when you have soils with abundant biology, vigorous biology, but you have imbalanced mineral chemistry, you can grow really healthy crops in that type of an environment. And so it is obvious that if you have imbalanced soil mineral profiles, it's possible for biology to overcome that to a degree. And I'll describe how you can determine what those degrees are for your soils and your operations. So this is kind of the foundational framework, the foundational premise of this entire conversation is we need to develop robust microbial populations and so that we can have, so that we can overcome any potential chemistry imbalances. So as I described the thought process and kind of the approach and the key parameters, as I was thinking about this presentation, the way that I've, I've come to the conclusion that this presentation, this outline that I've put together is really is the simplicity on the other side of complexity. And this is in reference to a quote that I think is originally attributed to Oliver Cromwell where he said, and I'll paraphrase just a bit, but he said something like, I really don't care about the simplicity on this side of complexity, but I care a great deal about the simplicity on the other side of complexity. And when we stop to think about that for any new skill that we learn, if we learn how to weld or if we're learning about agronomy and plant nutrition, whatever it might be at first when we're just approaching it, or if we're observing someone else doing it, if we're observing someone else welding, oh, that looks really easy. That looks really simple. That's the simplicity on this side of complexity. Then when we actually try to do it, all of a sudden we realize this is actually quite difficult and there's a lot involved. And if we keep at it, we keep practicing it, then all of a sudden it becomes very simple again. And that is the simplicity on the other side of complexity. And it really seems to me as if, though that is what this presentation summary really is, it's the simplicity on the other side of complexity. Because I looked at what I outlined and on the surface it seems really simple, and it is, but there's a lot behind it that needs to be executed well in order for it to deliver the types of results that all of us are really looking for. Some of the foundation concepts that I'm going to run through very quickly, we need to begin thinking of our soil as a biology lab. To do that, and to think of our soil as a biology lab means that one, we need to create the right physical environment for soil biology. We need to add the biology that has been lost. We need to constantly feed that biology with mulch, recover crops, we need to provide balanced mineral nutrition, and possibly, if we're interested and have the desire to, we can consider speeding up the development of that ecosystem with foliar applications and vertigation applications. And then there's a few other nuances that I want to touch on as well, such as avoiding excessive nutrient applications and so forth. So you look at this, this is the summary overview of what I'll be presenting. And on the surface it looks relatively simple, and it is. I want to begin by introducing James White's work on rhizophagy. If you're not familiar with this yet, you should be and you will want to learn more about it, then I'll just give you a brief introduction here. This Is the rhizophagy cycle. Work is based on research that was conducted by Dr. James White at Rutgers University and his colleagues, and was popularized in several literature, several white papers that he wrote. And then I hosted him on the podcast for an interview, conducted several webinars with him. And his information and knowledge is getting to be much more widely known, which I'm really grateful for. But essentially, what is the rise of aging cycle? The rise of aging cycle is the idea that plants are getting their nutrition from living microbes, from living bacteria, particularly bacteria in the soil system. So this is a completely different perspective on plant nutrition than the idea that plants should get their nutrition in the form of simple ions, Calcium, magnesium, ammonium, and nitrate ions from the soil solution. So what James is describing is that as plant root tips are growing through the soil, are extending through the soil, this growing root tip is actually quite porous, and it is engulfing or in essence, swallowing or inhaling entire bacterial cells. And these bacterial cells are moving back into the root. And as they move back through the. Through the root, and also as the root tip extends, the plant root releases reactive oxygen species, Particularly nitrous oxide, and it strips the cell membranes off of these bacteria. So now you have essentially naked bacterial cells without a cell membrane moving through the roots vascular tissue, and for that matter, eventually onward and upward into the plant. Then these naked bacterial cells are, or pieces of them are absorbed by the plant cells through a process known as endocytosis, where, if you'll just imagine a large balloon, like a water balloon, and if you poke a finger into it, then you get this divot down into the balloon. And that's essentially what happens with plant cells, is they capture these bacterial cells into these divots and just again, essentially swallow them whole. And then once these bacterial, these naked bacterial cells are inside the plant cell, the plant uses either the entire, Uses pieces and parts of this bacterial cell, the nucleic acids and different proteins and enzymes and so forth, and uses them to build its own cell and to maintain that cell. So then, however, some of these bacteria, some of these naked bacterial cells survive this process. They are not all immediately consumed by the plant cells. So as they move back through the root system, plants, they trigger the formation of root hairs. And as these root hairs are formed, these naked bacterial cells move back out into the soil environment. And there's a few interesting pieces that happen here. One is that the plant also communicates to these organisms, to these bacteria inside the root, what its nutritional requirements are. So it tells the bacteria, I need more phosphorus, or I need more manganese, or I need more zinc. And then these bacteria move out through the root hair tips back into the soil environment. And really interestingly, plants do not just these plant root tips do not just release the bacteria back into the soil environment, but they also release mucagel and specific carbohydrates and proteins that are precisely what the bacterial cells need to reform their cell membranes. So the plant is supporting them specifically so that they can reinoculate the soil and then communicate this informational message to the rest of the soil's microbial population. So now this message spreads, not just to these bacteria that were released, but it rapidly spreads through the rest of the both fungal and bacterial population to say, hey, my host plant needs more phosphorus or needs more zinc or manganese. And the entire microbial population begins focusing on extracting more of those nutrients and providing it for the plant so that the plant continues to feed them. And then as this microbial population develops and extracts more nutrients, along comes another root tip and consumes more of these bacteria that now contain the manganese or zinc or phosphorus or whatever it is that the plants require. So this is. This is a really incredible process. It completely reimagines plant nutrition. And these types of processes have been described in the literature for over 100 years, but they have not really been widely accepted until very recently. And this is actually a really big deal from a plant nutrition perspective and from an agronomy perspective, because for the first time, there is an understanding of how plants absorb nutrients that are not simple ions. So we know that there is no one fertilizing the forest. There is no one fertilizing native ecosystems. Yet these native ecosystems have abundant, adequate or abundant levels of calcium and magnesium and all these different nutrients, including nitrogen and phosphorus and potassium. And where is it coming from? There are very small, very tiny amounts of soluble ions soluble in the soil solution in native ecosystems, and yet these plants seem to have really good nutrition. So this is an explanation of the process by which plants get nutrients in natural ecosystems and our domesticated crops, the plants that we're growing for food or herbs and so forth, also have the same capacity. And it is this capacity that if we want to have robustly healthy plants that have highly functional immune systems and produce high concentrations of plant secondary metabolites, we need them to be absorbing their nutrition in this form of living microbes. So when you think about this, this means that a plant's digestive system is similar to the rumen of a ruminant animal. Or perhaps to our own gut linings as well, where it is really the biology that provide nutrients to the plant. Nutrition is completely a biologically mediated process. And by the way, so what this means, when you think about plants sending feeding bacteria and all these organisms and sending them back out into soil profile to release what is out there, this means that plants are farming bacteria much the same as we farm livestock. This also means that plants are not vegetarians. So plants are farming bacteria and they're consuming bacteria and consuming entire bacterial cells as a protein source, as an energy source, and as their foundational source of nutrition. It is how this is the process through which they get not just nitrogen and carbon from the soil, but also how they get mineral nutrients, zinc, manganese, copper and so forth. So what this means from a practical perspective is that we need to consider our topsoil layer as a laboratory petri dish. We want this layer to have as abundant and active microbial populations as possible. When we're successful in having these really rigorous biology, they have the capacity to supply the plants nutritional requirements within some boundaries. And I'm going to talk about what those boundaries are and how we can adjust them and move them. So when we think about this as being a petri dish zone or a lab of biology zone, then it becomes obvious that it is critical to regulate water temperature. And this is important in any environment. But it's becoming increasingly important given the climactic vagaries that we are experiencing in the last decade or two. And excuse me, it is not enough in today's environment, it is not enough for us to say that I'm going to develop really high organic matter content soil so that they can hold lots of water. And I'm going to depend on that as my mitigation to mitigate and give resilience during drought conditions and during high rainfall events. It's very important to do that. I'm not discounting the need for that. But having high organic matter content soils is not enough to mitigate the effects of getting 5 inches of rainfall in 48 hours or having that happen three times in a nine week period. So these are the types of severe weather events that we now have to accommodate, that we didn't have to accommodate as frequently or as often a longer period of time ago. And so now we need to regulate water and temperature within these environments much more closely than we have in the past. So what does this look like from a perspective of regulating temperature? Soil surface should never be bare. When you have bare soil exposed to the sunlight, it can Heat up to a temperature of 140 degrees Fahrenheit or warmer on the soil surface and as much as 110 to 120 degrees Fahrenheit, 3 to 4 inches down, depending on how the soil was aerated and tilled and how much carbon it has. In all those different variables, we know that enzymes are denatured when you have temperatures warmer than 110 degrees. So anytime we have this, really, we have a bare soil surface exposed to the sunlight that has the effect of shutting down enzymatic activity and shutting down microbial activity. So from my perspective, if we want to develop these robust microbial populations, we cannot afford to ever have bare soil. Soils need to be covered either with living plants or with mulch. It's not acceptable to have soil surface exposed to the sun. When we think about regulating moisture. Our observation and experience has tended to be that biology can survive dry environments. They go dormant, or they live on the very thin water films on soil particle surfaces or within aggregates, and then they recover when rainfall reoccurs again. But they cannot survive and do not do well for extended wet periods. And when I talk about an extended wet period, it's not really all that long. Basically, if you have the soil saturated for about 72 hours or longer, that is enough to deplete all of the dissolved oxygen that is within the soil aggregates and also within the water profile. The moment you've depleted all the dissolved oxygen, now you have, now you begin having the effect of quickly change the soil's microbial profile and shutting down many of the beneficial organisms that we need to have these vibrant ecosystems. So having saturated soils for an extended period longer than a day or two is really not acceptable. If we think about managing the soil as a petri dish. I've come to the conclusion that given the climate that we live in, drainage is an imperative. There's different possibilities. One is if we have soil that has a good slope and the surface water moves off quickly, and we protect that soil surface with mulch or cover crops or so forth, then that might be enough. But if we don't have the advantage of a slope or water moving off quickly, then we need to facilitate water moving off quickly in other ways. And I have. Over the last decade, I've observed a new form of field tiling here throughout northeast Ohio and through Pennsylvania that I am incredibly impressed with. Instead of using 4 inch drain tile buried 36 to 48 inches deep and 20 to 25ft apart, we're now using growers are now Beginning to use shallow drain tile that is only 2 inches in diameter and it's buried maybe 15 to 18 inches deep, 12 to 15ft apart. And I have been really impressed with what I've observed so far. First of all, the drain tile is shallow enough and close enough together that when we do get those 3 inch or 5 inch rainfall periods, or when we have six or eight weeks of continuous wet weather, they are shallow enough and close enough together to rapidly help that top a horizon, that topsoil layer dry out and allow us to keep our beneficial biological populations. On the other hand, they are also shallow enough that they do not disrupt the natural water table and they allow the water table to come up high enough that root systems can still reach down into the water table in really dry environments, really drought conditions. So I've been really intrigued with what I've observed using these systems. They're now the oldest ones that I've observed are about a decade old. And at this moment I am still extremely impressed. So after we've looked at adjusting the physical profile in terms of managing temperature, managing moisture, the next piece we need to look at is adjusting the mineral profile. So here's an important piece. Dr. Aleningham and other microbiologists have said that if you have really abundant microbial populations, they can supply 100% of a crop's nutrition requirements. That can be true, but it's not necessarily true. And that can only be true when soils have the native geology, the native rock profile that contains all the minerals that the crop requires. So if you have a rock formation that provides generous levels of potassium and phosphorus and manganese and zinc and so forth, you may have a geological bedrock material that supplies all the minerals that crops really need, with the exception of, let's say, selenium and molybdenum. And when that is the case, we cannot rely on biology to deliver nutrients that are not present. So our shift, our manner of pulling soil analysis and adjusting mineral profiles has shifted over the years. Where today we have a slightly different approach and the approach that I'm recommending for market gardeners specifically for this conversation, to pull two different types of soil analysis. And you pull them one time only. The first is a geological assay from there's. This is essentially a mining assay. So this would be the type of analysis that miners run to evaluate the mineral profile of a rock ore sample. So there's a couple of laboratories in Canada that run these samples. There's agent labs in Ontario, there's ACME labs in British Columbia, and While not a geological laboratory, I have been informed just recently our team has been using, has been getting quite a few samples back from Midwest labs that are running this type of assay. And this type of assay is really valuable. Because it can show us what minerals are actually present in our soils and geological profile. So many of you are familiar with the CEC analysis, and I still recommend pulling that one time only. But there can be significant differences between those two when we look at different types of parent rock material. So we had one of our consultants had an interesting experience just a couple of weeks ago, looking at soil analysis that had this geological assay from Midwest labs side by side from soils that were collected in the Midwest, in Nebraska, if I recall correctly, and then also in Florida. What was really interesting is that on the CEC analysis, both of these soils reported that they had 10 parts per million manganese, which is not enough for the Midwest extraction. We need about 20 parts per million on the Florida soil, which is very sandy. The geological assay, the mining assay, also showed that the sum total of what was in that geological profile was 10 parts per million. In other words, everything that was there was already showing up on the CEC analysis. And so if you wanted to increase manganese supplies in that soil, you have only one option, and that is to add more. However, on the Nebraska soil, this soil was also only showing 10 parts per million on the CEC extraction, but on the geological assay, it showed 400 parts per million. So for that soil, we don't need to add more manganese. You just simply need to develop the biology to extract and to release what is already there. So this is how we're taking a slightly different approach because we are seeing that biology has the capacity to extract these nutrients and make them available for plants, but only dependent on what the geological profile is. So our approach has been to use these geological assays to determine whether we really truly need to add more or whether we only need to develop biology to be able to release what is already there. So in the way that we are using the cation exchange capacity analysis that many of you, I'm sure, are familiar, running samples through Logan Labs, which is still the laboratory that we use primarily. And the way that we're using this analysis today, we're using it primarily for calcium and magnesium balance and for sulfur, zinc and boron levels. And it's even, even zinc is a toss up for zinc. We also defer to the geological assay to a large degree and then for all the other nutrients with the Exception of calcium, magnesium, sulfur, zinc and boron. We defer to the first assay. Do we actually truly need to add more or do we just need to extract what is already there? Or maybe do we need just to add a tiny amount to kickstart the biology and the plant system to release more when they have a higher level of health? The additional factor that we need to look at is paramagnetism. This could be a whole topic in and of itself, but we know that plants don't grow from nutrients as in npk, calcium, magnesium. Biology doesn't grow just from sugar and, and carbon, hydrogen, oxygen, hydrogen and so forth from all these different elements. Instead, they derive their energy from the energy contained within these molecules. And it's a bit challenging to talk about energy because it's such a nebulous concept. And the word energy can mean so many different things, can be used to describe so many different things. It's not really an accurate description, but what we can conclude, and what is quite obvious in anyone who has evaluated the research, is that soils that have high levels of paramagnetism support thriving populations of biology and plants do much better in those environments. So I believe it is imperative for us to make sure that our soils have very good paramagnetic levels. And I would generally recommend adding paramagnetic rock powder, such as basalt, either into compost or onto the soil profile to rebuild soil paramagnetism. And again, this is somewhat dependent on your native geology. If you are on. If your native geology is a basalt bedrock, then you probably don't need to add any more because your soils are likely quite paramagnetic already to begin with. So once we've looked at shifting the physical environment and adjusting the mineral nutritional environment, now we get to the actual heart of the conversation of the need to regenerate biological activity. And so I would propose that on a market garden scale, we need to build our own high quality compost. And I've come to really respect and appreciate the results that I've observed with the Johnson sue bioreactors. And they're something that is appropriate and easy to use for a small scale. You can also use vermicompost, and I'm an advocate of doing both. And that raw material can then be used to develop compost teas for fertigation for foliar applications, if that is something that we want to look at, particularly for disease control and so forth. And it can be useful to add any necessary or needed soil amendments into the compost if they are needed, and if it's appropriate from a ph balance perspective. You certainly want to. Compost is not the place to add materials for calcium magnesium corrections or ph corrections because you can easily have the composting system become too alkaline or too acidic. So it's best to apply that directly to the soil. But trace minerals and so forth can certainly be added to the compost and it generally has the effect of increasing their bioavailability. And then I have a recommendation which is a bit unusual, or at least I don't hear many other people talking about this in a market garden context. I'm going to highly recommend avoiding the use of animal manure based compost or soil amendments. Why? Because what we have observed with our SAP analysis work is that usually the majority of disease problems, the majority of insect problems are a result of the excess of nutrients that are applied by the growers, not by deficiencies. And the most common excess of nutrients are nitrogen, phosphorus and potash, which come or which are particularly concentrated in animal based manures. So what I have observed is that it is, it is very difficult, I won't say impossible because it seems almost anything is possible somewhere in the world. But it is very difficult to develop excessive levels of nitrogen, phosphorus and potash implants when our compost is plant based. So we can add all the mulch and all the COVID crops and all the plant based compost we want, but we don't seem to easily. As long as we have good biology, we don't seem to easily develop excesses of nitrogen, phosphorus and potash. But when we use animal manure based compost in a market garden context, often amendments are applied or compost is applied in large quantities for weed control and so forth. And it's often measured in depth and inches of thickness, whether it's a quarter inch thick or 2 inches thick or whatever the case might be. And when you do the math of how many tons per acre this actually represents and the quantity of nutrients that you're adding, it's an astoundingly high level of nutrients. And it is this over application, particularly of nitrogen and potassium, that is at the foundation of most insect challenges with flea beetles and aphids and kind of the list goes on and on of all the insects that are a result of excess of nitrogen and potassium. So I highly suggest avoiding excesses of those materials. Then the next stage. I also have an unusual suggestion in that compost compost teas, whether they are from Johnson sue bioreactors or from vermicompost or the combination, in my opinion are not enough in terms of re inoculating biology. And the reason they are not enough, they are very powerful, very useful, and I'm strongly in favor of them. But there are many of our really beneficial microorganisms that colonize the rhizosphere, require a living plant root to propagate. So mycorrhizal fungi is a classical example. You will not find mycorrhizal fungi in vermicompost. You will not find mycorrhizal fungi in any compost because, or I should qualify that to say you will not find it in any compost that does not have living plants growing on the compost pile, because you have to have living plants and growing root systems to propagate some of this really important biology. And it is for this reason that in our consulting work on larger scale operations at aea, we use purchased inoculants, both mycorrhizal inoculants and other inoculants, because there are a lot of biology that you cannot replicate in a composting system. So I think that is something else that I wanted to point out that you really need to take a look at. We often find that compostee applications, they're very valuable and they do a lot to regenerate soil biology, but they're not enough to get to where we want to go quickly enough. So then the next step, of course, once you've added biology, you've provided the physical environment, is you need to feed biology every day. They need to eat, even more importantly than a baby chick needs to eat. We know that the smaller the animal, the more frequent feeding times it requires. If you consider a baby versus an adult baby needs to be fed every two hours versus an adult could easily do once every eight hours if needed to. And imagine what that looks like when you get down to the size of a microbe. They need a constant food source all the time. There cannot be a delay that cannot be shut off. So biology needs to be fed constantly, either with mulch, where we have the soil mulch, with straw or hay mulch, or with COVID crops. And I really think that I'm a big fan of COVID crops because cover crops do things that mulch does not. And excuse me, I've been doing lots of presentations and I've stretched my voice a little bit over the last couple of weeks. So I've included a list of COVID crops that are exceptional in my current understanding of them, in the ways that they develop disease suppressive microbiomes and the way that they stimulate Soil aggregation. Ultimately, when we have this petri dish perspective, our goal is to have that entire a horizon, that topsoil layer, be really well aggregated and be able to put your hand in as deep as that topsoil layer goes without any problems. And soil cover crops have the effect, with their root systems of producing aggregation and soil aggregation particles much faster than mulch does by itself. So we developed this concept of using synergistic stacks when we put together foliar applications and fertigation applications. And I wanted to bring this concept to this conversation as well, because it's very appropriate if you want to build on this foundation and speed up the overall system's performance. You can do that with fertigation applications or with foliar applications that bring these different materials together into a synergistic stack. So when you look at a synergistic stack, you can combine compost tea and a microbial inoculant, seaweed, materials, plant nutrients, trace minerals, you can put all these together. And the intention, when I talk about speeding up the overall ecosystem, it is really photosynthesis that drives this ecosystem. It's photosynthesis synthesis that captures carbon dioxide and produces sugars and sends more sugars out to the soil biology to, to reinvigorate and to speed up soil biology. So the more sugars we can send to the root system, the faster the soil biology will develop. And as a result, increasing photosynthesis is really the pathway to achieving that in the most effective way possible. So this is why I'm such a fan of using these foliar applications to increase the photosynthetic potential of a crop. And I would also add that when you use these compost teas, microbial inoculants, as foliars, then they usually, particularly if they're well produced, they will have the effect of enhancing disease suppression on the leaf surface. So you will have less challenges with mildews and rusts and so forth on the leaf surface. So, in summary, I would say approach the soil as a biology lab. We need to create the needed physical environment. That means the right temperature and water management. And again, I go back to where I started this presentation. This sounds so simple. This sounds, and it really is. It is easy to do. It's not difficult. But if you think that this is too simplistic and that, oh, it's okay for me to till my soil and have tomato rows that are four feet apart and to have bare soil, I'll overcome that with doing other things by growing cover crops and so forth. You're not going to get there. I just want to disabuse you of that notion right from the beginning. You cannot skip steps. You can't cut out part of the recipe. It takes all these pieces together to produce a really regenerative ecosystem that we're looking for. So once we have created the right physical environment, we can reinoculate biology. And then we feed it all the time, make sure that we have the right balanced mineral nutrition. And if we're interested, we can speed up that system with foliars and avoid excessive nutrients. So that's the conclusion of my presentation. We could go see. The interesting part is that we could go into lots of questions to say, I apologize for my voice. Please bear with me. We can ask lots of questions such as, should I add molybdenum? Should I add selenium? What's a good recipe for a foliar application? I've deliberately avoided going into that type of conversation for this presentation because my intent has been to make it as simple as possible, but no simpler. And so when we look at this from a perspective of developing a recipe, this is the recipe. It truly is this simple. And you will not be successful if you try to make it simpler, if you try to cut out certain pieces, if you try not to do cover crops or try not to keep the soil covered or try to not have good drainage. Taking any shortcuts will cost you without really any exceptions. How much it will cost you, of course, will depend on the environment and the context, but you'll not be successful at achieving the types of results that you're looking for. So that concludes my presentation, and I'm going to open it up for questions, questions and answers. All right, we've got quite a few questions here. I'll flow through them as well as I'm able. Question from Matt. How do you feel about tarping areas with silage tarps before they are planted? Does it heat the soil too much and hurt it, or because it's covered from the sun, it can't affect it. So, Matt, the answer is that it is that there is heat produced underneath the silage tarps. That heating effect does have the effect of, to some degree, sterilizing the soil. It obviously inhibits weed germination and it also kills biology down to a certain depth, which causes a flush of nutrient release. And that's sometimes considered to be a positive. The question that you really have to think about, and I understand this might be needed during a transition period or for management practices, for weed control and so forth. So the question that you need to ask yourself is to what temperature and to what depth? So if you're thinking of your soil as a laboratory petri dish, then are you comfortable? Are you okay to kill the weed? Seasonal biology. Down to a depth of an inch, down to a depth of 2 inches. How deep does it really take to get the effect that you're looking for? Do you need to go any deeper? So the advantage, of course, is that if you have a soil biology layer that is really vigorous and healthy, down to a depth of 4 to 6 inches or deeper, should be deep, will rapidly grow deeper if you follow this, this protocol that I've outlined. And if you only kill the top 2 inches, then it can recover and reinoculate from the bottom upwards very quickly. But if you have a layer that's only two inches deep and you kill the entire two inches, then you've really set yourself back very significantly. You need to kind of start over, for lack of a better term. There's a question here from Linda. How does one measure the existing paramagnetic rock powder content of the soil? So there are paramagnetism meters called pcsms. Philip Callahan Soil Paramagnetic Susceptibility or something like that available from Pike Lab supplies because about $600. I'm sure there's probably also people within the BFA that have those meters and are using them because you really only need to measure once. So there's no point in getting a meter. I'm not sure if there's any laboratories that are measuring this currently or not. I don't know the answer to that question from John. If you're adding paramagnetic material into compost and then using the compost for teas and extract to spray, are you still getting the benefits of the paramagnetic material to the soil? I would say the answer is no, John. My reason for suggesting adding it to the compost is because it does really stimulate biology and so it'll stimulate the biological activity within the bioreactors or within the compost pile and is very valuable in that regards. But then I was also thinking of the next step of actually adding that compost into the soil environment as an amendment. There's a question from Dave for CEC analysis. Do you give credits to using strong or weak acid in the testing? You just have to make slight adjustments in evaluating the results between those two. So we use both ammonium acetate and malic 3 extractions all the time in our work. So I don't think there's significant enough discrepancies on most soil types to be worth really having a debate around the question from Daniel, how does one inoculate mycorrhizal biology into the soil? This seems very tricky because of the unique environment this fungi and bacteria need to survive. Daniel when we have the approach that we have taken, which has generally been very successful, is to use mycorrhizal fungal inoculants as a seed treatment. And this seems to work well when we have seeds that remain in the soil, like corn seedling, for example. So when you plant a corn seed, the seed itself stays in the ground and the seedling emerges. It seems to work less well when you have a plant that pushes the seed out of the ground, like a bean plant or a pepper or tomato plant. So when it pushes the seed and the coat out of the ground, the dicots, then you have the effect of removing the inoculant from the rooting zone. So we still get some effects, but not as much. So our approach generally has been to use a seed treatment as much as possible and then also perhaps to just inoculate in the furrow at planting or to put it into transplant media or whatever else is appropriate if we're using a transplant drench and so forth. Question, why do I recommend moisture? In Germany, we say it belongs to sausage but not to soil. And in monoculture I see bad soil physics. Why are not legumes in your cover crop recommendations? So mustard is a great question, a great observation, and I should have clarified my addition of mustard. Mustard is essentially a biofumigant, and when it is a useful cover crop, when soil has become so degraded and biological populations have become so degraded that we have a lot of nematode pressure, for example. So if we have a lot of nematode pressure, then mustard can be a useful cover crop to add and to incorporate to clean up the nematode population. It will also damage and suppress the existing microbial population and then to recover from that and rebuild from that. It's not. Mustard is not a cover crop that I would necessarily include in as a standard recommendation for soils that are already healthy. That's a great question and Jonas, and thank you for asking that. I should have clarified that earlier to your second question. Why are not legumes in your cover crop recommendations? They could be, certainly alfalfa and clovers and so forth could be in those recommendations. But I'm making these recommendations again in the context of market gardens and keeping in mind that they often want to rotate crops very quickly and get back into vegetable crops. So I'm usually looking at summer annuals or overwintering crops or crops that winter kill in that context. And legumes often don't have enough time to grow in those types of ecosystems, so they certainly could be included there. But they also, I should also add that the legumes do not have the same degree of disease suppressiveness and they do not have the same degree of soil aggregation as the other crops that I mentioned. So I just mentioned those as the top five that I see bringing the most value the most often in building soil the fastest. There's obviously an argument to be made for cover crop diversity, and you could suggest that instead of having five species or five primary species, we should be including 20 different species. And I certainly would be in favor of that. But just narrowing it down to saying these are the most effective that I've observed at producing disease suppressive soils and aggregating soil profiles. Question from Sherry. Are there any smaller cover crop plants that can be used to grow between plants that can support the biology of soils? You could do some, such as white clover, and there's probably a few others as well. But in those types of environments, I would be in favor of using mulch rather than using living covers. And my reason for saying that is because the living covers do compete with these plants sometimes for water and so forth. And you may need to, if, if you are irrigating, then obviously you can counterbalance that. But if you're not irrigating you, maybe you may be better off using mulches rather than using living cover crops. Question from Julie. Hi, Julie. Can a static compost of leaves or wood chips that sits for a year be as effective as the Johnson Sue? The short answer is no, it cannot. I've been really impressed with what I've seen from the Johnson sue bioreactors. And there's some unpublished research which was done privately in Europe from a grower who collected composting compost samples who were supposed to be the premium compost from different compost producers all across Europe using different methodologies, all the way from Humus compost using the Lube Key system to including Johnson Hsu. And I think there were seven or eight different permutations, dozens of samples. And when it came to actually changing so they, and they tested them in the laboratory and they tested them in the field. And when it came to actually producing changes in the soil biological profile, the Johnson sue material or compost tea that was used outperformed all of the others, even though in the laboratory it looked the same. So this was one grower's experience. It's very well documented, has not been published, and I'm not sure that ever will be. It was done privately, but I've observed similar experiences where the Johnson Sioux compost has been really exceptional. Question from Dave how do you kill your cover crop? Lots of different possible options. You can roll it, crimp it, and if you notice, nowhere into my presentation did I say that you should not till. I believe it's possible. I know it's possible because I've observed it. It is possible to incorporate your cover crops with tillage and maintain this type of soil biology and soil tilth long as you then immediately get your soil cover again with the next cover crop or with mulch. And it certainly is possible to damage soil structure with over tilling as well. There's a few caveats that could be offered there, but it is possible to till soils and to maintain this this exceptional aggregate structure and this biological petri dish. Another question does organic mulch or dead mulch feed the same microbes or similar microbes to the one that root exudates from COVID crop support? It's my understanding that they do not, and which is why they also do not have the same rapid effects on improving soil aggregation as living root systems. The living root systems from the five cover crops that I mentioned, with the exception of mustard, produce soil aggregation and stable soil aggregates faster than a living, faster than a surface mulch will by far Question from Matthew what is your best estimate for the ratio of mineral uptake by biology compared to chemistry? The answer is in what context and in what ecosystem? If you're out in the if you're talking about forest soils and how trees absorb nutrients, I would estimate that it's probably 95% in favor of microbial processes rather than chemistry. Processes of being in the neighborhood of around 5% for prairie native prairie ecosystems, it's again, probably the neighborhood of 90 to 95% in favor of biology A comment. You said that the rhizophagy cycle describes how plants get their nutrients in natural ecosystems. I guess what you mean is that the rhizophages cycle is one way in which plants get their nutrients in nature in addition to mycorrhizal associations or taking up soluble nutrients and yeah, it's a good correction. My understanding is that it is perhaps the primary way, certainly not the only way, but it's the primary way. Mycorrhizal fungal colonization and association and the contribution of mycorrhizal fungi is also very important part of that. And I'm not sure exactly how the math divides into how much the fungi are contributing versus how much the bacteria are contributing, but I anticipate between those two those are the clear significant majority. As I answered the other question just a moment ago. Question from Steven Johnson Compost seems great, especially as an extract to coat seeds, but the composting process takes time, especially to build a more complex microbial mix with fungus. So if you are just starting out and you don't have the luxury of time, are there seeds commercially available that are already coated with compost extracts? The answer is no, not that I'm aware of. Or are there compost extracts already made to coat seeds and for cover crops and for cash crops I'm purposely noting extracts rather than teas. And Stephen, I would say I'm not aware that there are any extracts made, but I would anticipate if you connect with the right people who are currently have their own bioreactors, you should be able to get enough compost to make your own tea. So that would be the route that I would suggest. Another comment I think many market gardens have excess of levels of phosphorus like ours which inhibits zinc and mycorrhizal fungi. Will biology overcome this or is there something I can actively do to address high phosphorus levels other than phosphorus solubilizing bacteria? Yes, biology does have the capacity to overcome that and yes it is a significant challenge. It goes back to the comments that I made earlier about many of the challenges being result of excesses and nutrient excesses being applied. So obviously the first rule is stop adding any more of what resulted in the in that excess of phosphorus level in the first place. It is possible. I would particularly recommend in that context, I would particularly recommend the use of oats buckwheat as cover crops because both of those cover crops are strongly associated with mycorrhizae and they are strongly associated with phosphorus solubilizing bacteria and they both have a uniquely pronounced effect on releasing locked up phosphorus in the soil profile. So I would start there and you will see a gradual rebuilding of mycorrhizal fungi populations over time if you use those cover crops. Question from Laura how do you feed the biology every day? Are you talking about doing one of the following every day such as fertigation or foliar sprays, etc. No, what I'm talking about is having living plants all the time. That is kind of the ideal or the optimal living plants that are green and photosynthesizing, producing sugars and sending sugars out through the root system are feeding soil biology every day. Alternatively, you can also have the soil covered with mulch decomposing plant material. That would also have the effect of be feeding them every day, but it is not as good as having living plants and living root systems. Question from Leonie have you discovered any differences in the time or season in which non living soil addition applications are made as to their effectiveness? Hmm, that could actually trigger a really interesting conversation about what defines non living. But at any rate, how do you draw that boundary, particularly when rocks are singing and emitting photons of light? In general there are slight differences, but for the most part we are adding our we find that we add most of our soil amendments in the spring rather than in the fall, unless there is a very significant and very large correction that needs to be made for calcium to magnesium balance. So if we're adding large quantities of limestone, or if we're adding large quantities of basalt for its paramagnetic effect, then we would typically do that in the fall instead of in the spring. But with those exceptions. Except for those exceptions, we would typically do a spring application There's a question about whether the Hemisphere Book is about rhizophagy, and the answer is no. If you want to dig deeper into rhizophagy, I've written a couple of blog posts about it that you can find on john kempf.com and I would also highly recommend the podcast interview that I did with Dr. White as well as an online course that he put together for us that is available on the Academy. Question from Kara Are there any situations in which you might plant crops directly into your living cover crop? The answer is yes. We do this all the time on commercial field scale production crops and there's actually a lot of information online if you look. If you just do a search on YouTube for planting green, you'll find lots of farmers talking about their approaches to planting seeds. Not even transplants, but planting seeds directly into a standing green cover crop. Question from Tom do you subscribe to the Albrecht Major Cation CEC balance scheme? Interesting question. Interpreting the Albrecht soil analysis is a bit like learning to speak English as a second language. Not only do you have to learn all the rules, but you have to learn all the exceptions to the rules. And there's a very long list of exceptions to the rules. And that long list of exceptions to the rules all revolves around the fact that the Albrecht soil analysis does not take soil biology into consideration. And so I actually hosted or spoke taught an entire webinar on this topic specifically earlier this week actually was two days ago and it'll be posted on YouTube in the next couple of days I'm sure. So I forget exactly what it was titled but we talked about I think was titled Soil Testing 2.0 and our approach today we still use the CEC analysis on all the farms that we work on. We still collect those samples because they're what many people are familiar with and are comfortable with. But we primarily use them for calcium to magnesium balance, sulfur, zinc and copper. Excuse me, not copper, boron, sulfur, zinc and boron. Five elements. That's it. Everything else we defer to SAP analysis and or the geological assays we look at the rest of the picture because we find that there is no correlation between the presence of nutrients on a CEC analysis and actual measure crop absorption There's a question what are your feelings in using plant based compost that chickens have access to turn, eat and defecate in? Should we still stay away from this level of animal manure? I would expect that would be less of a problem. The question is how much or just think of it in terms of how much animal manure are you applying per thousand square feet of per acre? I would guess it would be quite minimal. But the moment it starts approaching levels that are measured in tons per acre then we need to exercise caution. What are good trees to grow as a crop and overstory to blueberries? A tree that will do well in acidic soils amongst the blueberry farm in Southern California? Haven't thought about this and it's not particularly an area of expertise, but my thoughts immediately go to some of the honey locusts and I don't know if honey locusts would be appropriate for that climate though, but they would do well in acidic soils. There are trees that would do that. And it might also be worth asking the question what trees do well around blueberry bogs in wild ecosystems? I don't know the answer to that question, but that might be a good place to look. Another comment this past fall, in addition to the fall soil Primer, I inoculated 100 pounds of biochar with a soil primer mix in the hope that this would help more biology survive harsh conditions like very wet winters. Am I off base thinking this? Not necessarily. It's known that biochar does help biological populations establish become established and maintain themselves. The moment you start using the phrase very wet winters, that raises some concerns for me because what I can say.