How Humic Substances Reduce the Need for Nitrogen

Hi, friends, this is John. A few weeks ago, I had a call with our agronomy and consulting team at Advancing Eco Agriculture to talk about the mechanisms and the modes of action for our humic product called Humacarb. The team really enjoyed the conversation. We talked about a lot of information that isn't widely known and wanted to share that with the rest of you as well. So here's the recording of that conversation. Hope you enjoy.

So why is Humicarb better than a commercially extracted humic acid? Well, we know that humate has an extremely high cation exchange capacity. Dec, depending on which part of the mine you sample and some of those inherent variabilities within the deposit, you'll get numbers that range anywhere from about 280 to about 300. So you're talking about CEC levels that are dozens of times higher than the average soil. And in addition to that very high cation exchange capacity, these stable humic substances also have a similarly high anion exchange capacity. They have not just negatively charged sites, but also positively charged sites that they can attach and hold on to anions. And while there is less research that has been conducted on the anion exchange capacity, it's my understanding that the anion exchange capacity is similarly in the neighborhood of about 250 to 275 on most of the samples that have been tested. So there's a whole conversation that we could have around anion exchange capacity, but in reality, that anion exchange capacity is proportionally much higher than a CEC of 250 or 280 to 300. Because in soils, when you have a cation exchange capacity, you have your major cations being calcium, potassium, magnesium and sodium, which you need to hold large quantities of in the soil, particularly calcium and magnesium. You know, we're looking generally at thousands of pounds per acre of calcium and magnesium. But let's just say for the sake of discussion, that you have a soil that has a CEC of about 20, and generally the anion exchange capacity is much, much lower than the cation exchange capacity, maybe only 10 to 12%, sometimes as low as 4 to 5%. So in a soil that has a CEC of 20 will only have an anion exchange capacity of perhaps 2 or 3, because the quantity of anions that need to be held within the soil are much less than the calcium and magnesium. So you might only need to hold a few hundred pounds per acre of phosphorus and sulfur and nitrate, for example. So when you start to think about it, a humic substance that has a cation exchange capacity of 280 to 300 and an anion exchange capacity of 250 to 275. There's something quite remarkable about the fact that the anion exchange capacity is almost as high as the cation exchange capacity. It's not a 10 to 1 ratio, it's almost a 1 to 1 ratio. So the anion exchange capacity of these humic substances is extremely high, which allows it to hold a tremendous amount of anions, particularly nitrate and sulfates, in solution. But the interesting part is that the anion exchange capacity is mostly held in the human fraction, which is spelled H U M I N. There is some anion exchange capacity in fulvic acid, but very little, almost none, in humic acid. Most of it is stored in the human. So the reason humicarb is so much more effective at holding nitrogen is because it is not alkali extracted. It still contains all the human. And now we have extremely high cation exchange capacity and anion exchange capacity that we have released within that container. So when we do the math and we look at the combination of particle sizing and the very high anion exchange capacity, that math will tell us that when we include humocarb at 3% of the solution, that is enough anion exchange capacity and enough cation exchange capacity to hold all of the nitrate and all of the ammonium that it is combined with. So with nitrate, you have an anion. With ammonium, you have a cation. You have both anions and cations. So that concentration of humicarb is enough to stabilize that and hold all of it. And essentially at that point, it's no longer soluble in the soil solution. It is available for the plants to absorb, but it's no longer soluble, which is why it prevents leaching, etc. And by the way, this is something that potassium hydroxide extracted humic acid cannot do. It can't have this effect to nearly this degree because it no longer contains the human and it no longer contains this extremely high anion exchange capacity. That's one of the big reasons for the differences between humicarb and humic acid. So in addition to that, there's something very important that happens in the soil profile. When you add humicarb to liquid nitrogen and you put that combination of the soil, if you were to add just straight liquid 28, for example, or liquid 32, that addition of soluble nitrate and ammonium is one of the most severe disruptors to the soil's biological populations that are known. It's more severe than many pesticide applications. It's A major shock to the soil microbial community. And what generally ends up happening is the soil microbial population, particularly right in the rhizosphere, becomes dominated by pathogenic organisms that now have the opportunity to flourish and thrive because you've removed the control populations that keep them suppressed. Humicarb can single handedly, with one shot, reverse that negative effect of adding what are effectively toxic levels of nitrates and ammonium to the soil microbial community. There's a dozen different types of humic acid available on the marketplace, and I believe, and there's field evidence that shows that humicarb is substantially better than the competition. And the reason for that is it still contains that human, it still contains the very high anion exchange capacity when you extract it using a chemical extraction process. And you lose all of that. Yes, you still have a chelation capacity because the humic acids and the folic acids are still chelators. So you still have the chelation capacity, but you no longer have the high anion exchange capacity. So what happens is when you add a conventional humic acid to nitrogen and you put it out into the soil, there is a stabilizing effect on the nitrogen where it will stabilize and hold the nitrogen stable for a relatively short period of time. And when I say relatively short, I'm talking about depending on soil temperatures and rainfall, etcetera, anywhere from about 10 days to about 21 days. And then the humic acid begins losing its hold on the nitrogen on the nitrates and the ammonia because it is more attractive to other elements within the soil profile. So when you look at the chelation constants I've talked a bit about in the past, humic acid is going to be much more attracted to, in particular silicates, but also to all of the other trace minerals in the soil profile, also to potassium. So what happens? The humic acid begins releasing nitrogen and attaching to potassium. So this can be a good thing if you want to increase potassium availability. This is why many growers often see a slight yield response or a grain quality increase when they add humic acids and they notice a slight potassium increase because the humic acid serves as a potassium solubilizer in the soil profile. This is not a bad thing, this is a good thing as long as you want for that to happen. But what you don't want to happen is you don't want the humic acid to release the nitrogen that quickly. You want it to hold on much longer and hold it much more stable. And the humic acid can't do that, but the human can. And that is why having the human in that profile is so important. Sumicari will hold nitrogen stable in the soil so that it does not leach. You don't have any water pollution, it doesn't go down into the aquifer, it doesn't go into the river. It will hold it stable and it will still be available for the plant to absorb in 60 days from now. And in 90 days from now, it's not going to disappear. It's a claim that humic acid can't make. If you want more information and more details on this, I did a webinar. It is posted on YouTube. It was titled Preventing Nitrogen Phosphorus Leaching. And I described some of the effects and benefits of human and these various humic substances in stabilizing and holding nitrogen and phosphorus stable in the soil profile. And so if you're looking for more information, you can follow up with that. But it is very clearly described that human and the various fractions of humic acid have very different interactions with nitrogen and with phosphorus. In the soil profile. Liquid humic acid, alkali extracted humic acid has an extremely low anion exchange capacity. In fact, it's almost non existent because the part of humic acid that has that capacity is gone. It's been stripped out. So let me say that humic acids are effective. It's not that they're ineffective, but their effect is produced very differently. Instead of holding onto the nitrate through the anion exchange capacity, it is holding onto it through the anion version of chelation. So when we talk about chelation, the technically correct terminology, a chelate is always a metal ion, such as a calcium, magnesium, manganese, zinc, copper. It is an ion that is surrounded by an organic molecule. That will be the technically correct definition. All right, well, what happens if you don't have a metal? What happens if you don't have a cation but instead have an anion such as phosphate or sulfur or nitrate? Well, in that case, a chelate is no longer the correct terminology. So they now call that a complex. So now you have nitrate that is surrounded by an organic molecule, in this case humic acid, that is now complex. So it's the anionic version of a chelate. It's a bit of an oversimplification, but that's essentially what it boils down to. So extracted humic acid does complex nitrates and it can complex ammonium as well. And again, you can't talk about an ammonium chelate because it's a molecule and not a single ion. So when you have humic acids that have complex liquid nitrogen, they do hold it stable in the soil. But again, the caveat, the downside, is that they will release it in a 10 to 20 day window. And now you have this flush of free nitrogen which you still want to avoid. So the big differences between humic acid and humicarb is that humic acid will hold on to nitrogen for a week or two, three, and then release it. Humicarb never lets go. It holds it stable in the soil profile until the plants absorb it or until bacteria metabolize it or something happens with it. It will not leach. It won't end up in the aquifer or down the river, and you won't end up creating a nitrogen flush in the plants with it.

If you have any further questions about humicarb, call the Advancing EcoAgriculture team at 800-495-6603. Thank you for listening and have a great day and a great grow.