Podcast Short #2 - Pool Parties and the Soil Microbiome

Hi, friends, this is John. Welcome back to the Regenerative Agriculture podcast. I've been looking forward to a fun conversation today. It's the middle of June. Temperatures for the week are forecast to be topping out in the 90s every day. And over the weekend, I set up a small pool for my daughter to play in. And I was reminded of an analogy that a friend shared with me a long time ago on the similarities between having a pool party and building soil microbial populations. This might not seem like a very apt analogy, but it brings out a couple of highlights that I think are very important for us to think about, that we often don't think about. When we think about having a pool party, what is it that we want to achieve and what does it take to have that or to put together a really great pool party? When you think about, of course, to have a pool party, be very successful, or to be considered successful, you need a crowd. You need lots of people that are having a good time, lots of fun with each other. And to facilitate that, it's easiest to facilitate that. When you have the right ecological niche. In other words, when you have the right temperatures, when you have elevated temperatures and the right weather conditions, a pool party becomes a lot more appealing. Very quickly, of course, you need to have the pool itself. You need food, you need drinks, you need good company. We could transfer all of these pieces to thinking about the soil ecosystem and the soil microbiome, you need the right environment, the right ecological niche, type environment. So similar to where with a pool, you need to have the right temperatures in soil, you also need to have the right temperatures. You need to have the equivalent of the pool is that you need to have soil that can be colonized, soil with reasonable aggregate stability and structure. You have the equivalent of food, you need liquid carbon, you need to have carbohydrates, sugars, so forth, moving through this little profile available for consumption, you need to have water and you need company. You want a crowd, not just one or a couple or half a dozen people. The larger the crowd, the greater the diversity, the more fun the party can be. Not necessarily, but the more fun that it can be. When you think about this framing, the question that was asked of me some time ago that really caught my attention is if you want to, let's say that you want to have 200 people show up for a party, who do you need to invite? To have 200 people show up, do you need to invite all 200 people? Having never been to a party, that was my expectation, that you need to invite all 200 people. If you want to have 200 people show up, but that's not actually the case. You don't need to invite 200 people. Who you really need to invite is you need to invite the top five or 10 people who are very socially connected and who attract other people in their presence. And when you have the five or 10 people who everyone wants to be around and who are the organizers, the social butterflies, the social networkers, those top five or 10 people, when they hear the others that are going to be there, they send out the word, they send out the message to their audience, to their connections, and you have a couple hundred people show up from a handful of invitations. The same concept also holds true for building our soil microbiomes. And so it's worth asking the question, what are the key who are the equivalent of these socially connected people? Who are the five to 10 people that can invite dozens of others or hundreds of others? What does that look like in a soil environment? And there are two frameworks, two ways that we could think about this. The one framework is thinking of it in terms of other biological species. So with the pool analogy, we have a small, select group of people inviting a much larger group of people in the soil microbial profile. Is there such a thing as pioneering microbial species that then attract many other microbial species to be present purely as a result of their presence in that ecosystem? The answer is yes. This is particularly true of mycorrhizal fungi. It's also true of other saprophytic fungi. But it's particularly true of the fungal community. But not just the fungal community alone, but there are specific bacterial populations, specific fungal populations, where a single species can be considered to be a pioneering species, or perhaps a better term would be a keystone species, that when you have the presence of this particular organism or this group of organisms, then that creates an environment that draws in that hundreds of other species want to be around. So all of a sudden, and there's this recurring conversation of the best source and the best use for microbial inoculants are what are the best microbial inoculants? Would it be, can they be compost teas from humified compost? From vermicompost? Is it from soil extracts, where we get soil from the woods and from different locations and we extract it, and we apply that out to a much broader application? Or do we consider the use of purchased inoculants that might only have a few dozen species or in some cases even a single species? And as in the Case of a Zodobacter, not Azodobacter rhizobium bacteria that we inoculate legumes with, or mycorrhizal fungal inoculants. There are an increasing and growing number of inoculants that feature a single species, but that yet produce a remarkable crop impact. And these single species are what I would refer to as a keystone species or as an influencer species that attracts and draws dozens of other or even hundreds of other microbial communities, microbial populations together until you have a much larger community, where once you have this much larger community, the party can really get started. You can have quorum sensing and quorum cooperation when you have very large, diverse, abundant microbial populations. And this can be facilitated by having a few of these keystone species that are present. And this is, I think, when we think about inoculants, purchased inoculants, the question we need to ask when evaluating purchased inoculants that are propagated in a laboratory is what is the consistency of their success? How many different soil environments do they produce a strong response in? Because some soil environments may already have the presence of that particular organism or group of organisms and may produce less of a crop response. So we need to start looking at consistency of response and recognize that the outcome, the influence of an inoculant, isn't necessarily a reflection of the number of species. You can have a purchased inoculant from a lab that contains a handful of species and produce a greater crop response than a product that is extracted from vermicompost or worm tea and might have tens of thousands of different species. It all depends on the context in the environment and how those materials are effective. But there's another. There's a second framework for thinking about who the influencers are in this hypothetical pool party that we want to create. And this is thinking about it not in terms of like attracts like, but who are the macro influencers in this system, in this ecosystem? And. And it is not other microbes, but it is in fact, plants. Boundaries between soil and plants are vanishing. When we consider the microbial population, the associated endophytes, the fungal endophytes and bacterial endophytes that live inside a plant and that surround that plant's exterior, that live in the rhizosphere out on the exterior of the roots and the exterior of the leaves. We used to consider these microbial populations as a part of the soil environment, but now we consider them as a part of the plant. They live both in the plant and in the soil. And so the boundaries between plant and soil are vanishing. In fact, once we start considering the soil microbiome, you could accurately say that the boundaries have completely disappeared, that there is, there are few significant differences between the soil microbiome and the plant microbiome. And that in fact, the similarities far exceed the differences. When you consider that different plant species from different plant families all have their own associated microbiome, then that means that each plant. In a conversation I was having with a group where Dr. James White was included last week, he described that when you open a seed, there are for many different crops. We were talking about corn in this particular context, but in a corn seed, if I understood him correctly, he said that there are 9 billion microorganisms inside a corn seed, 9 billion with a B. So the corn seed is a vector for a microbial population, as is a soybean seed or a flax seed, or a grass seed, or a chicory seed or any other plant. These seeds are all vectors for a microbiome. So if we want to get the party started, and we want to have not just hundreds but thousands of different species showing up to the party, we want to have this robust, strong community that has the capacity to develop a remarkably disease suppressive soil. The key influencers that we want to invite are the plants, because each plant brings hundreds or thousands of species to the party. So we need to begin thinking very differently when about building soil health, building abundant soil microbiome. It's not accurate for us. We need to start thinking about in terms of this, in terms of plant groups and plant families that we need to have more than nature doesn't have monocultures or very seldom, There are very few instances where we have true monocultures. We need to have a diversity of plant species because a diversity of plant species corresponds to a diversity of the soil microbiome, which corresponds to resilience within that ecosystem and a sharing an exchange of genetic information. And this is how we build very robust soils very quickly. But in order for all of this to happen, in order for us to have an amazing pool party, they need to have food and drink. You need to have the right environment, you need to have food sources, you need to have enough moisture for them. And this brings me to the reason I'm having this conversation today, in the middle of the summer instead of in the winter months, is many of us are in this situation right now. We have crops in the ground, crops are actively growing. Depending on which part of the globe we're on and what Crops we're harvesting, we may already be done with harvest. But what can we do to enhance and to grow the energy of the pool party that we are conducting in our soils right now? It is my observation that most agricultural soils, what is most limiting those soils from having a vibrantly healthy community of soil microbial population is they don't have enough of a food source, they don't have enough carbon available, microbially active carbon circulating in the soil profile. And to get more carbon into our ecosystems requires that we have abundant photosynthesis of really healthy plants. And you know, my observation and experience has been that when you have adequate water in an ecosystem for plants to photosynthesize, well, there are almost always immediate first year economic improvements and crop profitability improvements from a well designed foliar application. And the reason for this is because a well designed foliar application has one, the number one priority, the number one objective of a well designed foliar application is to increase photosynthesis. And this is a mistake. This is a reason why many growers over the years have tried foliar applications of nutrients and they haven't observed economic crop responses for the simple reason that the foliar application was not designed with the first priority of increasing photosynthetic efficiency. Instead, it was designed perhaps to address specific trace mineral deficiencies. And we put on an application of zinc, manganese and copper and iron and cobalt and boron, etc. Which many crops would benefit from. But if that foliar application doesn't produce a photosynthesis response, perhaps because the plant doesn't have enough magnesium or doesn't have enough sulfur, or doesn't have enough of something that could have been contained in the mix but wasn't included, now you've just greatly reduced the crop response from that foliar application because you've reduced or you haven't had a positive impact on photosynthesis. And it is this impact on photosynthesis when you we have this practice or these tools in our toolbox that we use when crops are severely stressed. Let's say you have a crop that has, if you have a potato crop that has a severe infestation of Colorado potato beetles, or you have a vine crop or grapes or tree crop or something that is has a severe infestation of Japanese beetles, this works with aphids, works with a number of different insects. Also when we have a crop that has hail damage, depending on the severity of hail damage, if there's an opportunity for the crop to recover, one of the tools that we use is to put on a foliar application that contains various different things, but one of the ingredients that is very necessary to include. We tend to use a lot of rejuvenate for its carbohydrate content. And rejuvenate has some enzymes and some other stuff in it as well that produce a very nice crop response. But the key for carbohydrates is that when you give a stressed crop, it can be as little as 5 to 10. I'm thinking of this in terms of sugar, because sugar is not a direct analog to rejuvenate. Rejuvenate is pretty high horsepower and has a lot more efficiency than just sugar does. But if you put on 5 to 10 pounds of sugar per acre in combination with biostimulants, then you can produce a very nice stress recovery response from plants in that way. Rejuvenate. We typically put on a smaller application, two to four quarts per acre, depending on the context and the scenario. But what happens is we get this tremendous plant energy response. Plants have the ability to metabolize ammonia that is produced from high heat stress. Plants recover very quickly when you give them this shot of sugars. But the reality is that this is a bit like giving a man a fish instead of teaching him to fish. It's a temporary crutch and you can actually have a much bigger and more sustained long term impact by putting on a foliar application that enhances photosynthesis and allows the plants to produce more sugar. Because the reality is if you put on a well designed foliar application that enhances photosynthesis, those plants on a given acre will increase their sugar production to the point where it's 20, 30, 50, £100 more. £100 of sugar per acre per day, which is much more than you can economically afford to apply. And this is why well designed foliar applications produce such a strong plant bigger growth response as a result of increased photosynthesis. But the way we got here to this point in the conversation is because what happens when you have this strong increased sugar production response and you have a crop that's producing 50 or 100 pounds of sugar in every 24 hour photoperiod, the majority of that sugar, depending on the stage of growth, the majority of that sugar is not going into the plant, it's going out through the root system as root exudates to feed the soil microbial population. This is how you bring abundant energy to the party that's in the soil profile. This is how we build a very vigorous and active soil microbiome is making sure that we have a diversity of plant species from very diverse families that have very diverse microbiomes, and then supporting them and feeding them. Well, when you do those things, soil health can recover remarkably quickly. And that's when the party begins. Let's all have fun.