Q&A With John Kempf on Large-Scale Broadacre Crop Production

Good afternoon, everyone. Welcome to the Q and A discussion. Happy to see you here. Hope you're all having a wonderful day and enjoying winter as well as you possibly can. As much winter as remains. Anyway, the intent and the purpose of the conversation today is not to I didn't prepare any presentation or any particular notes. Instead, it's going to be purely Q and A. Only some of you sent in emailed in questions in advance. So thank you for sending those. I'll be responding to some of those questions. And then if you have any questions that you would like for me to discuss challenges that you have on your farm that you would like to hear about solutions or have a discussion around, I'd love to have that discussion. And this is going to be a fairly informal and open conversation and I'll perhaps lead off by responding to some of the questions that were emailed in. There's been a theme on questions about the availability of trace mineral metals in the soil profile and the conversations that I've had with reduction versus oxidation and how this correlates to the various trace mineral metals, mineral availability, and the differences between soil analysis, tissue analysis, SAP analysis, etc. So I'm going to start there by answering some of those questions and then I welcome your input if there's any additional questions that you'd like to add. One of the questions that came in was can I elaborate on iron and manganese profiles in soil analysis and tissue analysis versus a SAP analysis? And what do soil analysis and tissue analysis really tell us about the availability of these elements? So here's the background and here's the context. For those of you who haven't heard me speak about reduction versus oxidation before, I'll give a very brief background. Essentially, as soils go through the weathering process, as they oxidize either through and this can be from the natural weathering, it can be through tillage. It can be through the applications of salt, fertilizers, nitrates, limestone, manure that has a high salt content. There can be a number of different things that have an oxidizing effect on the soil profile, and then it is the function of soil biology to then buffer that and balance that out and bring back the counterbalance to oxidation, which is called reduction in biochemical terminology. The key is that plants can only absorb several of the trace mineral metals in the reduced form, not in the oxidized form. And because of our historical management practices, or when we have soils that are very dry for extended periods, as many of you do in the plains regions with limited rainfall, when you have really dry soil environments, you end up with soils that are relatively oxidized and you have relatively limited availability of these various trace minerals. So for these specific metals, the specific metals that plants that is only physiologically active in plants in the reduced form are iron and manganese and copper and cobalt. Zinc is an exception and boron is an exception. Boron, of course, is an anion, is a bit different. It's not a trace mineral metal as these others are. Zinc is the one exception because zinc only has one oxidation state. So for all of these others, manganese, for example, can be present in the positive 2 or the positive 4 form in the soil. Iron 2, positive 3 or positive 4. You see it written sometimes in chemistry formula as, let's say iron with triple positive three. Those are all references to the different oxidation states. So the differences between soil analysis and tissue analysis and SAP analysis and how they report this. A soil analysis will pick up all of the iron and the manganese and the copper and the cobalt that is present in the soil system that can be extracted, both the oxidized and the reduced. So they show everything that is in the soil profile. And it can be possible for the soil analysis to show to have almost all of the manganese and iron oxidized. So it can show a very high number. And yet the crop is not able to absorb it or to utilize it with a tissue analysis, a dry matter based tissue analysis, or the same is true of a forage analysis. When we send it into a laboratory, whether it's a wet chemistry analysis or a near infrared analysis, those also pick up both the reduced and the oxidized form. And this is distinct. In fact, the only test that I know of for certain for which this is not the case is SAP analysis, where SAP analysis does not show a, it only shows the reduced form, the form that is physiologically active, and it doesn't show the oxidized form within the plant. And actually I had a very interesting conversation around this with a farm that we've been working with for several years in Canada and southern Ontario. And this farm had a history of having high iron levels and high manganese levels on the soil analysis. It was a dairy farm. They also consistently had high iron and high manganese levels on their forage analysis. And so they were, they were. This farmer was a bit skeptical that he actually had an iron and manganese deficiency. But I was able to show him, describe for him what it looked like visually and the specific things to look for in the field. He was able to go out in the field and observe that he had iron and manganese deficiencies, amongst other things and got a very favorable crop response from putting on foliar applications of iron and manganese. He started doing SAP analysis. The SAP analysis also showed that he had very low iron and manganese levels. But he was the first to point something out that really caught my attention. He pointed out that as he started using rebound iron and rebound manganese and he noticed it particularly with the iron applications as he started. So his iron analysis on his iron reports on his forage analysis showed as being consistently very high. His forage analysis showed that he had a surplus of iron, the crop was absorbing a lot. But the SAP analysis showed that the plants were actually deficient in the correct form of iron, the reduced form. So he started putting on foliar applications of rebound iron and the iron numbers went up very rapidly on his SAP analysis. And what was really intriguing is that they started dropping and they actually dropped. They were cut by almost in half in a single growing season on his forage analysis. And the growers hypothesis was that as the plants had more of the correct form of iron that they needed that they were able to use, they did not continue to absorb the oxidized iron from the soil profile. I'm not certain if that hypothesis is correct. I think it's something we need to do more digging on. But after hearing that, after seeing all of his analysis on his farm and started looking at it, I started looking at a number of other farms and I was able to find that that correlation was true in a number of different situations. There's one question that has come through from David Takahashi. Hi David, glad to see you here. Is there a way to measure soil organic matter that is accurate and quick, which can be done in the field itself. This would allow many measurements to be averaged at different locations and soil depths and results would be immediate. David, I'm not aware of any analytical method which can do that right now and it's not not particularly an area of expert of my expertise. So I'm not sure of what all new analytical methods are being developed. However, one of the things that we are working with a lot more at AEA in this coming year and into the future is we intend to begin conducting many more Haney analysis of the soil analysis that Rick Haney developed. And amongst other reasons, one very important reason we want to begin measuring them or using that soil analysis is because I told our team at AEA that the Haney analysis is to soil what SAP analysis is to plants. And in particular, in terms of measuring microbial activity. Sometimes farmers put on microbial inoculants, rejuvenate and spectrum, and they get this incredible response. Soil becomes much looser, and plants develop really large root systems. And other times there is also a response. In fact, I don't. I can't recall that we've ever applied rejuvenated spectrum and not seen a response. But the response can vary widely. Sometimes it's a. Sometimes there's a nice difference, and sometimes there's this wow response that really makes you raise your eyebrows and question about whether this is really possible. And those differences in response are not correlated to soil organic matter. You would think that they might be, but they're not. What they're actually correlated to, we're discovering, is they're correlated to the fraction of organic matter that the Haney analysis terms biologically active carbon. So it is possible to have soil that has extremely high organic matter, but that has very little active carbon. An example would be muck soils that are used to grow vegetables. They sometimes have 40% organic matter, but they have been fumigated, and anhydrous ammonia has been used, and these soils have really been degraded. So what happens is you might have these soils with really high organic matter, but the biologically active compound.