How to Manage Soil Nitrogen and Carbon Sequestration

Well, good evening, friends, and welcome to our webinar. I've been asked the question quite a few times recently as a standard part of our biological and biostimulant program that we use a lot is a fall application of Rejuvenate and Spectrum. It has some very powerful characteristics. It has an amazing capacity to develop soil biology very, very quickly, and it's become our most popular product because of of the results that it delivers for growers. The question has come up quite a few times recently is what is the limiting factor that limits biological development and the development of microbial communities in the soil profile? And how can we develop soil biology much faster? Specifically, how do we know whether a rejuvenated application that we apply on our farm can have the similar effects that it had on our neighbor's farm or one of the farms 30 miles down the road? How do we know if we can replicate those results and can replicate that effect? What is the optimal environment in which to apply the product? That, of course, has also been tied in with the question of how can we build organic matter and how do we need to manage nitrogen differently based on some of the results that we're seeing? So I wanted to speak to all those different pieces because they're all connected and they're all tied very closely together. The first piece that I want to discuss and describe is what are the limiting factors for developing abundant microbial communities? And then secondly, once we build really abundant microbial communities, what other management changes might we need to make to ensure that we keep the benefits that we got from all those microbial communities and don't negate any of the things that we're doing? The first question how do we build tremendous microbial communities? Particularly if you think of bacteria being the most rapid and most aggressive example. I've heard some microbiology professors and teachers describe how some bacterial populations, there can be an entire generation in seven minutes of some species, and for other species, maybe the average might be a single generational shift in 20 minutes. For some it's a few days. So when you think about that, even if it's just for a few days, but particularly if it's a matter of minutes, when you have this very rapid generational cycle, there's the potential to build incredible bacterial population. The key to building aggressive and very large volume and very abundant microbial communities is to make sure that they have an optimum environment. This is where I think, agriculture as a whole has fallen short. If we want to build really active soil microbial communities, bacteria, fungi, protozoa, nematodes, archaea, etc. Every one of these organisms really needs three things. It is usually one of these three things that is missing that will prevent the population from really growing and expanding. So these three are oxygen, water, food, and comfort. And oxygen isn't necessarily a requirement for all species, but it is for many of the species that we want to develop in our agricultural soils. I find this triode of these essential environmental requirements to be a bit intriguing because so often when we think about, okay, what is limiting the development of microbial communities in the soil profile, it's very common for growers to anticipate that the greatest limiting factor is water, and that water is what is holding back microbial development, particularly in very dry environments. If we have very dry environments where we're dealing with constant irrigation, such as California or southwest Kansas, Nebraska, Saskatchewan, etc. We often suspect that the greatest limiting factor for microbial development is water. But it's not. It's not water. It's food. In fact, I want to describe some of the science behind this. But when there is an adequate level of digestible carbon and soluble carbohydrates in the soil profile, biology can access enough water, even in drought conditions where plant roots can't get enough water. And I want to describe a bit how this works. So obviously, the first requirement, and a requirement that I believe it is important for us to discuss is oxygen and making sure that we have adequate oxygen in the soil profile. The ideal that this often raises the question of tillage versus no till. And how do we fix a hard pan or a plow pan if we have one in the soil profile? First of all, it is completely unacceptable to only be tilling the top 4 to 6 inches of the soil profile, only be farming the top 4 to 6 inches of soil profile. If we have a hard pan and roots are not penetrating below that level, then we need to get rid of the compaction. We need to resolve the compaction issue. From my observation, my experience, there are many who would advocate seeking to remedy a plow pan or a hard pan by using plant roots, by using cover crops, etc. Tillage, radish, and so forth. And those are certainly a very valuable tool. However, in my observation, in my experience, they are often not enough and too slow. The most effective tool in our observation is actually using iron, using machinery and equipment, using deep rippers to aerate the soil profile, and then using using cover crops and using plant roots to maintain that openness and to make sure that that compaction doesn't develop again. So it is important to make sure that we have good aeration and oxygen flow into the soil profile. And also this is something that rejuvenate can help with tremendously. One of the common attributes and the common reports that we hear from growers who are using it is that their soil becomes much softer. It can become softer quickly with a rejuvenate application down to 10 to 12 inches. But in the cases where we have severe compaction, rejuvenate is still not a compaction remediation tool in and of itself and by itself. So we have to address this issue. This is something that can't be allowed to continue if we want optimum crop health and crop production. But the second piece then we need to look at is water. And here's why. Water is not the problem that we might anticipate that it is. So when soils are at field capacity, with moisture at field capacity essentially means that the soil can't hold any more water. If you had a vertical soil column and you add one more drop to the top, then one drop is going to come out of the bottom. The soil can't hold anymore in that structure. So that's what is termed field capacity, or stated a different way, 100% moisture. So 100% of moisture holding capacity. When we have powdery dry soil that is dusty dry, that will blow in the wind. When you measure the water held within that soil profile, dusty dry soil still contains 70% of fuel capacity. And you ask yourself, how is that even possible? How is it possible that completely dry soil can still be holding 70% of the water that is at field capacity? And the reason for this is because as soil begins drying out, there is this very thin film of water that is around each individual soil colloid, each clay colloid and silt particle, sand particle, etc. And that water is adsorbed to these colloids very, very tightly. So tightly that it is not available to plant roots. Plant roots can't absorb it, but biology can. In fact, bacteria can still live and maintain viable populations in these thin films of water. Mycorrhizal fungi can access this water. And this is one of the reasons why one of the characteristics that mycorrhizal fungal inoculated plants are known for is being much more drought resilient, because mycorrhizal fungi can tap into these thin films of water on the soil colloids and make them available to plants. So in fact, soils that would appear to us to be completely dry still have an abundance of water and they have enough water to maintain and to develop a strong microbial community. So it's not water that is the limiting factor in most agricultural soils. What is the limiting factor usually is a food source, which is soluble carbon. What do I mean when I say soluble carbon? It's a bit of a challenge to speak about the different carbon fractions and the carbon profile of what's happening with soil organic matter, because there is so much different terminology being used today. Some speak of green carbon and brown carbon versus black carbon, some speak of undegradable carbon or indigestible carbon, humic substances, etc. And none of those typical descriptions fit very easily for what I want to describe. So for this discussion, what I'm referring to is a fraction of a part of organic matter. So if you take this total organic matter, there is a part of that organic matter that is extremely stable. It's sometimes referred to as stable, stable humic substances or humus. And for the sake of this discussion, we're going to simply define that these stable humic substances as being insoluble carbon. In other words, they cannot be consumed, they can't be used as a food source by biology. And this is an important point to be aware of because sometimes people.