Feed, Fields, and Footprints: Sustainability of Iowa's Feed Supply

In this episode, Dan Andersen and Luke Soko discuss the carbon intensity of Iowa's livestock feed supply chain. The discussion emphasizes the potential for reducing emissions through efficient farming practices and the future market opportunities for low-carbon feed. 

Show Notes

Transcript

Copy

Dan Andersen: 0:06

Hello and welcome to Talkin' Crap, a podcast by Iowa State University Extension and Outreach. This institution is an equal opportunity provider for the full non discrimination statement or accommodation inquiries, go to www.extension.iastate.edu/legal. In this podcast, we discuss insights into the science, technology and best practices surrounding manure management. Our objectives are to build awareness about the challenges farmers and the broader agricultural industry face around manure and to demonstrate solutions and areas of innovation. Hello and welcome back for another episode of Talkin' Crap. I'm Dan Andersen, and today I'm going to be joined by Luke Soko for an episode on feed fields and footprints, evaluating sustainability in Iowa's livestock feed supply chain. So Luke, great to have you back on the podcast. Can you tell us a little bit about yourself to help refresh us who you were?

Luke Soko: 0:59

Absolutely great to be back. My name is Luke Soko. I'm a PhD candidate at Iowa State University. I've been working with Dr Andersen here for about four years now, and it's been great. And today we'll be talking about the carbon intensity, carbon intensity scoring of Iowa corn and Iowa soybeans.

Dan Andersen: 1:20

So a couple things on that. Use the term candidate there. How exciting for you. That means Luke passed his prelim, so he's pretty, pretty pumped about that, to be one step closer to graduation.

Luke Soko: 1:30

Yes, yeah. Very exciting and excited to one day go out and, you know, fund some autonomous research and get a lot of stuff done.

Dan Andersen: 1:39

Autonomous, huh? Not research on being autonomous, but research that you find a way to get paid for instead of me.

Luke Soko: 1:44

Absolutely, all right, absolutely.

Dan Andersen: 1:45

So as we get started today, when we talk about livestock sustainability, I often focus on manure or methane from manure, and a little bit on feed conversion efficiency, but the crops behind it matter a lot. Is that fair? Yeah. So when you think about the overall carbon footprint of a pig. Could you break down what comes from feed? What comes from manure? What's the other stuff?

Luke Soko: 2:06

Absolutely So, when we talk about a pig in Iowa, roughly 40% of its emissions are going to stem from its emissions associated with manure. That's typically methane emissions from the decomposing manure below the pit. And depending on where you are in the United States, you have different methane conversion factors. Also, you'll have about roughly 40% of those emissions from the pig will come from the feed itself that's associated with raising the crops. And that's what we're going to talk about a lot today, is that feed, that 40% from that feed and raising the crops, and then you have another 20% typically associated with transport and also powering the barn and other miscellaneous tasks.

Dan Andersen: 2:51

Perfect. So I think that gives us an orientation of maybe how this fits together in swine production, or what, what the carbon intensity might be of that. But I want to back up half a step and say, what got you interested into CI scoring at all? And then why livestock systems?

Luke Soko: 3:07

Absolutely So. Carbon intensity scoring is a way to measure the amount of greenhouse gas emissions and and I want to pause there for a second. So greenhouse gas emissions, that's carbon dioxide, methane and nitrous oxide, and we normalize them on a scale using what's called global warming potential, where one gram of carbon dioxide is one gram of carbon dioxide, 21 gram of methane is 25 grams of what's called carbon dioxide equivalents, or grams of greenhouse gas, and then nitrous oxide, which we'll talk a lot about today, is it 298 is one gram of nitrous oxide is equivalent to 298 grams of carbon dioxide equivalents, or grams of greenhouse gas. And so when we talk about carbon intensity scoring, we're talking about the grams of carbon dioxide equivalents, or the same thing, grams of greenhouse gas emissions per unit of fuel or food, and fuel or food, they're really the same thing. So carbon intensity scoring is common right now in renewable fuel production, typically with ethanol, biodiesel, renewable natural gas, you can be paid a certain amount of money through the Low Carbon Fuel Standard Market, especially through California, but also through programs in Oregon, Washington, British Columbia, New Mexico, but you can be paid money for reducing your grams of carbon dioxide equivalents per unit of fuel. Now, food is really the same thing. It's a fuel for us and it's a fuel for pigs and cows and beef and dairy, turkeys and egg layers all throughout Iowa. And Iowa is the number one corn producer in the United States, the number two soybean producer in the United States. It is the number one swine producer in the United States. And if we're looking at a system of feed where, if you look at a pig, and you're saying 40% of the emissions associated with that pig is from the feed production, and we are the number one pig producer in the United States. Well, how do we reduce that 40% how do we reduce those emissions? Is there a market for that? Our large and large animal producers, JBS, Tyson Smithfield, they're interested in reducing their carbon footprint. They have made aspirations of reducing their emissions by certain percentages, some by 2030, some 30% by 2030 depending on how they define their life cycle system. JBS had aspired to be net zero by sometime around 2040, 2050, so they're interested in reducing their emissions, and we're interested in figuring out, well, how can you reduce your emissions, especially through feed, you know? So we normally talk about, how do we reduce our emissions through manure? That's normally what we discussed. But we can also reduce the emissions through feed. So what we've done is we've looked at the Argonne National Laboratories GREET model. Now GREET has a model called the Feedstock Carbon Intensity Calculator or GREET FDCIC and they can account for all of the emissions associated of raising corn and soybeans. And so we can use that calculator, and we can analyze it using data for every single county in Iowa, and we can evaluate all of the emissions associated with producing the feed in each county in Iowa, and we can look at, hey, some counties in Iowa, they have much fewer emissions than other counties in Iowa. Why is that? What are counties doing differently in Iowa that makes the feed from this county significantly less carbon intense than a feed from a different county? And so using that data, we're able to really take a good look at what factors are influencing the carbon intensity of corn and soybean, what factors are influencing their carbon intensity of raising corn and soybeans,

Dan Andersen: 7:13

Perfect. So I think there was a lot to unpack there, but really we're interested in how can we still maintain being the premier state, and ideally the premier country, as the USA as a whole, in livestock production. And while there might not be a specific market right now for a low carbon pig or a carbon neutral pig, we're all interested in ideas of, how do we pursue that? What does it take to get there? And I'm going to hold you to a question I asked you specifically what got you interested in this topic?

Luke Soko: 7:39

Oh, yes, I'm really interested in reducing the carbon footprint of agriculture within the United States. Agriculture accounts roughly 10% of emissions, anthropogenic greenhouse gas emissions that the United States releases. But agriculture is a very interesting sector, because it cycles carbon in relatively short time spans and the whole if you think about what is the objective of agriculture, if you take a step back, what are we doing in agriculture? Well, we're really pulling carbon dioxide from the environment to generate food, feed, fuel and fiber products, and it's an industry that's entirely based on initially growing plant matter to pull carbon dioxide equivalent pulling carbon dioxide out of the environment. And so if you think about it that way, you're like, Well, why? Why is carbon Why is agriculture a net emitting industry, if its whole underlying principle is to pull carbon dioxide out of the environment to produce things necessary for humanity. And so I'm very interested in, how do we reduce the carbon footprint associated with agriculture, and then how do we combine agriculture with carbon sequestration projects, whether it's soil organic carbon sequestration, biochar, or whether we're pumping biogenically derived carbon dioxide into saline aquifers for long term carbon storage. How can we use agriculture to not only produce new products like food, feed, fiber and fuel, but also sequester a portion of that carbon to reduce the overall carbon footprint of agriculture?

Dan Andersen: 9:21

And I'm just interested in, how do I make the best pig that I can and be the premier pork producer, the premier egg producer, the premier milk producer. But it's the same idea. And like you said, agriculture is about 10% of US emissions, so not the major source, but it's an interesting source, and one that we feel has some opportunities, and like you pointed out, maybe even expanded opportunities to help some other sectors out, if we think creatively. So, you mentioned the GREET model and told us that that comes from Argonne labs, and you applied that GREET model, which is essentially a spreadsheet tool that helps estimate and track emissions for all the processes you do in a field. So if we think about a carbon intensity score of corn, what are the main factors that go into that? What sort of information did you need to collect to understand what that carbon intensity score was going to be?

Luke Soko: 10:10

So the main factors associated with the carbon intensity of raising corn grain are associated with the nitrous oxide emissions, associated with the incomplete denitrification of nitrogen fertilizers.

Dan Andersen: 10:26

All right, those big words, yes. How about you break those down for us and tell me what you mean.

Luke Soko: 10:30

Absolutely. So we apply corn is corn requires a lot of nitrogen. One of the fundamental reasons why in Iowa we love a corn soybean rotation is because those those soybeans, you don't have to fertilize them with a nitrogen fertilizer, and they can actually replenish some nitrogen back into the soil to allow corn to not require as much nitrogen fertilizer the next time that you plant corn.

Dan Andersen: 10:56

And I'm going to jump in on that, it's not necessarily that maybe they're replenishing it, but they put it in forms that mineralize quickly for that next corn crop, so they help adjust how it's going to be available, and maybe help that be a little more predictable for us.

Luke Soko: 11:09

Yeah, absolutely. And so corn requires a lot of nitrogen, and whether we're applying that nitrogen as manure or fertilizer, a portion of that nitrogen due to the biochemical processes from the bacteria in the soil, they are going to cause a release of some of that nitrogen into nitrous oxide, and it's typically referred to as about one to 2% of the nitrogen applied is going to be converted into nitrous oxide, which is emitted into the atmosphere. And you might say, well, one to 2% that can't be too bad, but nitrous oxide has 298 times the potency for global warming potential, which is to get back at that point quick, global warming potential is it's measured in a unit of intensity. It's watts per meter squared, and it's really the ability to absorb and re emit energy from the sun. So if we're talking about climate impacts, 298 compared to one, I mean, that's quite the climate impact from nitrous oxide. So most of the emissions from raising corn is actually from nitrous oxide emissions from the field itself. So the field receives fertilizer, and roughly one to 2% of that nitrogen is going to be released into the atmosphere as nitrous oxide, and that is the largest source of emissions for raising corn. Now the second largest source of emissions for raising corn is fertilizer production. So not only so now fertilizer really has a two a double whammy effect on the environment, because when we're making anhydrous ammonia fertilizer, it's a very energy intensive process, and that's why it's so difficult to have that natural biological fixation in nature to happen at such scale, because it's an energy intensive process to convert that atmospheric nitrogen into ammonia. So what we see is our largest sources. And to give you some rough numbers on what am I talking about when I say largest source? So approximately 45% of the carbon dioxide equivalents emissions for raising corn come from nitrous oxide emissions. 45% it's the largest, the largest source. Roughly 18% of emissions from raising corn comes from synthetic fertilizer production, and that's producing those fertilizers. And then, if we're thinking about, well, what about after that? Well, after that, I mean, you have a lime, depending on you, the acidity of your field, you may lime. Is a large source of emissions, less than 18% and you also have emissions such as diesel, although diesel is, once again, much less significant, less than 5% of your total emissions. So most of your emissions are really coming from nitrous oxide and fertilizer production for that corn, and that's because corn, corn requires a lot of fertile requires a lot of fertilizer if we want to make these groundbreaking yields that we continue to make in Iowa, maybe 220, bushels per acre. You know, that's going to require the necessary fertilizer to do that.

Dan Andersen: 14:15

But in some ways, yield is our friend. I mean, you pointed out that a lot of those emissions are from the soil, naturally, some from applied nitrogen. But one of the things that you found in your results, essentially, is that higher yields help reduce the carbon intensity score, mostly because if there's some baseline emission from the soil, writing that off over 250 bushel production, rather than 200 tends to help out.

Luke Soko: 14:38

Absolutely. So there are, there are three drivers to reducing the carbon intensity emissions of raising corn. One is yield, and yield is essentially saying we're being more efficient. If we're applying a certain amount of fertilizer and we're making a larger yield, we're more efficient when I look at the carbon intensity scoring of feed in Iowa, what we're looking at is the kilograms of carbon dioxide equivalents per metric ton of corn, of corn, DDGS or dried distiller, grams of solubles and soybean meal. So we're looking at the kilograms of carbon dioxide equivalents per metric ton of each of those feed items. And so if you are making more metric tons of corn, if you're making more metric tons of soybeans, you're going to drive down that carbon intensity because essentially, you're more efficient. Now the second way that you're going to drive down that carbon intensity score is if you're using nitrogen fertilizer of manure, you're using nitrogen in the manure. You're applying manure, essentially, if you're applying manure, then you negate the emissions associated with producing synthetic fertilizers. And I mean, that's significant, right? We said 18% is synthetic fertilizer production. So if you're applying your nitrogen in the form of manure, and a manure also has great concentrations of phosphorus and potassium. I believe that it's roughly if all the manure in Iowa can supply roughly 30 to 40% of the phosphorus and potassium needs, and roughly 30 to 40% of the nitrogen as well. And so those are the two drivers, big yield and manure application, as opposed to a lot of synthetic applications, synthetic fertilizer application.

Dan Andersen: 16:31

So the manure is essentially saving the energy of producing new nitrogen fertilizer or mining potassium or phosphate fertilizers, but the nitrous oxide emissions from the manure compared to commercial fertilizer, there's a lot of variability in the research, but roughly the same from at least a first order estimate. So it doesn't change that part of your analysis, but it does save that energy that would go into making fertilizers. Okay? So one thing that didn't come up in your discussion there, and then I think we hear a lot about is the impact of soil organic carbon, or storing carbon in the soil. Could you talk through just a little bit about what GREET incorporates for soil organic carbon storage, and where does that rank it, or how important is that in our CI scoring?

Luke Soko: 17:16

Absolutely. So it's very important. Soil organic carbon in the greet model is based on five factors. So the first factor is the baseline case. You're going to pick a scenario where you are essentially you want to measure SOC in the change of SOC, there's already carbon in your soil. So what you're measuring the change of well, if I do this practice, how much more soil organic carbon will I add, or how much will I take away? And let's also talk about the importance, if we're adding carbon to the soil, that carbon was initially in the atmosphere. That carbon was in the atmosphere, the plant had absorbed some of that carbon, and it decomposes into the ground. And a lot of that decomposition re-releases that biogenic carbon back into the atmosphere. But if we're increasing the amount of soil organic carbon, we're converting some of the carbon dioxide from the atmosphere, and we're sequestering it into the ground. So that's what's so enticing about and also soil organic carbon has been linked to higher fertility and better yields, and so it's why would we not want to increase this? Right? So that's an excellent goal. In the model, it's based on five factors. You pick your initial baseline scenario. Our baseline scenario is a corn soy rotation with strip tillage or reduced tillage, depending on how you define it, no manure application and no cover crops. And then in the model, you can pick crop rotation, you can pick the amount of cover crops. So you pick it is based on crop rotation, cover crop, manure application, and tillage practice. Those are your four factors that you compare to your baseline factor. And what we've seen is that it, I mean, it has a tremendous impact. So if we look at an average, if we look at an average corn soy rotation, soil organic carbon, can reduce the overall emissions of your farm by eight to 10% of raising the crop.

Dan Andersen: 19:25

Great. So it's not a game changer, but it does matter. And I think you pointed out of a couple important things there the baseline or where we're starting, probably makes a difference. Some soils will be more adaptable to increases in carbon from certain management practices than others. Those things that you suggested, manure application, cover crops, reduce tillage intensity, and then just rotation in terms of how much stuff is it adding back to the soil, all are sort of playing with that carbon balance, of how it might work, and at this time, there's still a lot of uncertainty in those carbon budgets. But GREET does a nice job of at least a first order approximation of what these practices might do, or how might they change.

Luke Soko: 20:07

Yeah, and and so roughly 10% but the impact potentially, of soil organic carbon, based on our results, are that if you had 100% of your land under cover crop, we're going to give you an idealist scenario, and you are applying all of your nitrogen fertilizer as manure, and you're doing a no tillage practice, and you're also planting mostly corn. Corn is a high amount of biomass, now there's emissions associated with fertilizers, but let's say you're using you're giving all manure to the fertilizer, you could hypothetically reduce your emissions by up to 25% so you could really have significant emission reduction through that soil organic carbon. And that's your third factor. So your three factors to reduce your emissions are high corn yield, manure, nitrogen on the corn land, because, of course, we're not applying nitrogen on soybeans and that soil organic carbon, which is a function of higher cover crop, more higher land area with no tillage, higher no till and a higher manure application.

Dan Andersen: 21:15

And there were other factors that influence it as well, the amount of fuel I use for field passes or the amount of energy I use for drying corn. But in the grand scheme of things, while those might be things we could do something with, they aren't driving big changes in the GREET model.

Luke Soko: 21:29

Absolutely and but, and what's exciting too, is that these things that are driving big changes are things that these these practices that we're looking at, they're already implemented. That to what amount are they implemented? And there are challenges with 100% implementation of anything, but these are things that we can implement in Iowa now. So the impact of this paper, when we release it, is that if you're an animal producer, hypothetically, you could source your feed from a farm that's doing that's completing these practices to reduce their carbon intensity scoring of their feed, which means that the meat that you're producing has a lower carbon intensity as well. And so as companies become more interested in reducing the carbon intensity score of their meat, as consumers become more interested in purchasing meat that has a lower carbon intensity score, as opposed to another meat. And also, there are voluntary markets that exist that pay roughly $30 per metric ton of carbon dioxide abated. And there are also new markets being proposed all the time for this reduction in carbon intensity. If as those markets come online, as a animal producer, you might buy feed that has a lower carbon intensity score than another farm, and if you're doing that, then you're going to be reducing the emissions of your animal, and that might be associated with legitimate revenue in the future. So we're trying to set the stage for look, if we produce feed in different ways, we can really drive down the carbon intensity score of meat, and that can be a lucrative market in the future, especially as I mean, we talk a lot about anaerobic digestion, reducing the emissions associated with manure for the pig. And now we're looking at methods to reduce, you know, if we're no tilling, if we're increasing soil organic carbon, applying manure, having higher yields, we're more efficient. We can drive down the carbon intensity scoring of the feed as well.

Dan Andersen: 23:31

Yeah, and I think those are all some great opportunities. They're things like you said, that we can think about implementing now, working towards what markets might develop in the future. I want to move us along a little bit. And one of the things that I get asked about this topic is, I'm going to feed a byproduct, let's say distillers. How does that influence my carbon intensity score, compared to just feeding corn? How do we handle or partition some of those processing dynamics into what happens?

Luke Soko: 23:55

Yeah, absolutely. So, dried distiller grains of solubles that corn DDGS. It accounts for roughly 30% of the mass of the when you put the whole corn kernel into the ethanol plant, you're going to be making ethanol. You're going to be making corn DDGS. You're going to be making corn oil, and you're also going to be making a concentrated stream of carbon dioxide from the fermentation of the corn, and roughly 30% of that mass is going to be the corn DDGS and I it's roughly 20% of the value in that system. Ethanol processing is relatively energy intensive. In fact, we looked at the processing from ethanol and producing ethanol from corn has roughly the same amount of emissions roughly as raising the corn itself. So there's a lot of emissions associated there with the fuel production you almost form you're raising the corn, and then you're producing the fuel, you're almost doubling your emissions. And so part of that is partition to the corn DDGS. Now I'm going to go off track a little bit and talk about soybean meal. Soybean meal represents about 80% of the mass of the soy product, and it represents roughly 65% of the value of the soy product. And along with that, when you producing soybean meal, you do that at a crush facility where you take the soybean and you crush it and you use hexane to extract this soybean oil, and what's remained is that soybean meal, that process is less energy intensive than ethanol production, and you're also producing more product than soybean meal. This is all to say that if you're feeding a diet that's corn and soybean meal, you're going to have less carbon intensity. You're gonna have less carbon dioxide equivalence emissions, a lesser carbon intensity score with a corn soybean meal diet than compared to a corn corn DDGS diet. The corn DDGS will have higher associated emissions per metric ton of that feed, in comparison to the soybean meal and in comparison to the corn. And it's obvious for the corn, because you're what you know, you have corn versus corn, plus this intensive processing to make ethanol, but it is. It's even more interesting that the corn DDGS is particularly more emission intensive than the soybean meal.

Dan Andersen: 26:30

And a couple of things on that you mentioned that process intensity is important. So how much energy I'm spending gets added to that product, but you're using an economic allocation. So in the case of DDGs, 80% of the emissions of growing corn and the processing are associated with the ethanol, 20% with the DDGS. Is that right?

Luke Soko: 26:49

Yeah, yeah.

Dan Andersen: 26:51

So even though a lot of it goes the other way, there's still enough energy used there that corn and soybean meal, depending on exactly how the partitioning works out, soybean meal tends to work out favorably, at least from the yields and calculations that we've done.

Luke Soko: 27:04

Yeah, and it's both. So it's partitioned. Emissions are partitioned by value, but we also incorporate how corn DDGS is only roughly 30% of the corn, so we're making less product, even though there are less emissions associated with it.

Dan Andersen: 27:20

That's right, yes, that's a great point. It's not like we still have a ton of DDGS. After you've done corn, you're down to a third of a ton.

Luke Soko: 27:26

Yeah.

Dan Andersen: 27:26

And they got 20% of the emissions from the corn, 20% of the emissions the process. And there's just not a lot left there to write the emissions off towards. All right, I wanted to get towards your results. I think that's one of the more interesting parts of it. And in the show notes, we've included one of the maps that Luke has made for us, sort of showing the variation in CI scoring by county. So certainly, we often think about CI scores per farm, but when you don't work with a specific farm, you try to understand maybe what the variation is in Iowa. Looking at it on a county makes sense, because you can find a lot of the data you need at the county level.

Luke Soko: 28:03

Yeah, absolutely.

Dan Andersen: 28:04

So as you think about what you saw, why was there? What was the variation between counties, between high and low, for example, for corn, and then what was driving that?

Luke Soko: 28:14

For corn, you're going to have, we have found that the lowest carbon intensity scores are associated with Northwestern Iowa, where there's high yields and also lots of livestock for lots of manure applied to the fields, and we also see some practices of no till and cover cropping, increasing soil organic carbon. So let's say this northwestern region of Iowa, you have roughly about 150 kilograms of carbon dioxide equivalents per mega gram of corn, or mega gram more metric ton, same unit. So 150, if you go to the worst county in Iowa, we had some in this southern portion of Iowa, there are lower yields in comparison to the northern portion of Iowa. And there's also, in some cases, less livestock and more conventional tillage, depending on where you are. And so we noticed that in some counties in southern Iowa there were higher carbon intensity scores, and a higher carbon intensity score for corn could be roughly 250 to 300 kilograms of carbon dioxide equivalents per metric ton.

Dan Andersen: 29:20

So you're saying in a good county compared to maybe the worst county in Iowa, we're talking maybe 50% reduction in carbon intensity score per bushel of corn generated.

Luke Soko: 29:28

Yeah, roughly 50% so. And that is kind of the cornerstone of how impactful this is, that just by looking at current farming practices in the state of Iowa, there are carbon intensity scores from some counties, which are roughly 30 to 50% less than other counties. Let's say, if you're in the far eastern part of the state, you might say, well, I can't get my feed from northwest Iowa. Well, no, you can't, but people, farmers around you could adopt the same practices that northwestern Iowa utilizes, and then all of a sudden, their feed has a lesser carbon intensity score. And then if you buy feed from them, then your meat has less carbon intensity score.

Dan Andersen: 30:08

Yeah. So I think while we can move corn around a fair amount, processing places matter, and maybe we won't be hauling feed all over, but trying to understand what's driving some of those differences between counties, so that you can have a more accurate to your area location makes some sense, and it also gives us some insight of what you could potentially achieve if you were buying specific source corn or attributed corn to really understand that carbon intensity score and drive some differences. So I think that's really interesting to me. I'd like you to maybe talk to me about what were the big things that you really saw drive that down. I know you mentioned manure. How big? What was the biggest factor? Really, the lowest counties were driven by XYZ. What are the important things?

Luke Soko: 30:48

Yield, manure, nitrogen, manure, application and tillage practice,

Dan Andersen: 30:56

Maybe rotation, a little bit, right?

Luke Soko: 30:57

And rotation, rotation is interesting. Yeah, elaborate on rotation.

Dan Andersen: 31:02

Probably, I think we should elaborate a little on rotation, because when Luke's first started making these results, I think it was a little counterintuitive to what you saw. And one of the challenges, I think, when you look at this at a county level, it sometimes feels like certain things are maybe linked together, especially counties that tend to have more manure, might run more continuous corn rotations.

Luke Soko: 31:20

Yes, yes. So counties that do continuous corn rotations typically have higher yields anyway. So they have that to their advantage. They typically you do a continuous corn rotation, because you can expect high yields every single year you have more manure around. If you have a lot of manure around, you might be interested in doing continuous corn, because you need to apply the manure somewhere, and there's a lot of nitrogen in manure, and corn needs a lot of nitrogen. So those work out hand in hand. They work together. And also, corn has a lot of biomass, and biomass is effective at increasing the amount of carbon in our soils. So we can see with the continuous corn rotation, we see lower carbon dioxide equivalence emissions per unit of feed. And that's not to say that continuous corn is going to reduce the emissions of agriculture. That's not what we're saying. We're saying that there it is correlated that continuous corn in counties is typically in counties with higher yields, with more manure and producing more biomass. All three of those things are reducing the carbon intensity score. However, if you were doing continuous corn in a county with not enough manure nitrogen to really supplement your fertilizer, and you're not having high yields, and you're not efficient, all of those things can factor into a bad carbon intensity score to say.

Dan Andersen: 32:41

It's an opportunity and a curse, right? I mean to really take advantage of continuous corn one of the things you pointed out is we need to have low energy nitrogen fertilizer, whether that be green ammonia or that manure available to us. We need some way to make sure we're keeping that component of the corn production system relatively low to take advantage of it. And I think that it makes it a little more confusing to interpret, but it's also an honest answer. There may be opportunities in certain places to say continuous corn with that green fertilizer, whether it be manure, whether it be green produced anhydrous ammonia, can help lower carbon intensity scoring in some areas. So as we think about what you've done here. I want to give you a chance to say, sort of the big picture. What's the take home? What should we be thinking about, and where are we actually headed? Because I think right now, a lot of the markets don't exist, but people are exploring them.

Luke Soko: 33:32

And so where we're headed is reducing the, by being able to reduce the carbon intensity scoring of corn and soybeans in the state of Iowa, we can also reduce the carbon intensity scoring of producing meat, of producing milk, of producing beef, of producing biofuels. Like in Iowa, ethanol can even be converted. There's a method called alcohol to jet where ethanol could even one day be used to make jet fuels sustainable aviation fuel. But all of that starts with corn and soybean at the beginning. And when you think about the process of raising corn and soybeans, all of the carbon in the corn and all of the carbon in the soy initially came from the atmosphere, and we can be more efficient at pulling that carbon dioxide out of the atmosphere using our agricultural products, we can begin to drive down the carbon intensity score of meats, milks and fuels across America and that, I mean, that's really our goal. And as markets expand, as companies receive more pressure, and also companies are competing with other technologies. There are technologies emerging all the time. For example, there's lab grown meats, there's cell based meats. Let's say hypothetically, if those technologies claim that they can be greener than livestock, now they're competing in a market. So companies want to compete and be a lower carbon intensity fuel, a lower carbon intensity meat, a lower carbon intensity feed, so that they can compete against new innovations in the emerging, you know, the ever expanding industry of agriculture.

Dan Andersen: 35:15

And I think for me, we often see Iowa as a leader in this space already. I mean, when, when you look at some of the things that drive carbon intensity yields a huge driver. And Iowa is a high yielding state in general that helps us have some of the low carbon corn available in the market. And it's our place as a leader in the US and in the world to continue to try and innovate and bring that down. And then, as a manure specialist, I'm always excited when you tell me, well, manure is an important player in this if we can better utilize those manure nutrients, making sure that we're taking advantage as as much of it as as we can, getting it to the acres that need it, spreading the phosphorus and potassium around so we're really taking advantage of it, the general manure practices that we talk about are things that we can take advantage of to help produce some of those attributed products and make sure that we are competitive as we move forward. So that I wanted to thank you for your time today, Luke. I think was a great conversation. I really appreciated it. Thank you for joining this installment of Talkin' Crap. Be sure to take a look at the show notes on our website for links and materials mentioned in the episode. For more information or to get in touch, go to our website, www.extension.iastate.edu/immag/. If you found what you heard today useful or it made you think, we hope you subscribe to the show on your podcast app of choice. Signing off from a job that sometimes smells but never stinks, keep on talking crap.