Fertilizer and the Iran War with Rory Maguire

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Travis

One of the widely reported concerns with the ongoing conflict in Iran has been our ability in the United States to get products from that region. And one of those products has been fertilizer. This made me curious as to why that was the case with fertilizer, and that sparked my curiosity as to what's fertilizer made of anyway, why do crops need it, and what happens if we can't get enough of it?

Well, thankfully Virginia Tech's Roy McGuire had the answers to all these questions and more and was kind enough to join the podcast. Rory is a professor and an extension specialist in the Virginia Tech School of Plant and Environmental Sciences. He is also the supervisor of the Soil Testing Laboratory at Virginia Tech So Rory was the ideal person for me to ask my fertilizer questions to and he was able to explain to me what nutrients actually make up most fertilizers. He was also able to explain to me why some of those nutrients, specifically nitrogen, is impacted by the ongoing war in Iran and why that nutrient is a little bit different in how it interacts with our soil than some of the other nutrients commonly found in fertilizers. He was also able to explain why some soils have different needs than others and what some of the alternatives could be to nitrogen which is the part of the podcast where I get to say chicken poop for the first time.

So if you like me have been curious as to what plants actually need to grow up and become their best selves, I think this podcast will take root with you. I'm Travis Williams and this is Virginia Tech's Curious Conversations.

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Travis

Well, I want to talk to you about fertilizer because fertilizer has been in the news a lot And I guess maybe to start that conversation, when we hear about fertilizer, when we're talking about fertilizer related to stuff that's happening overseas, what are we actually talking about?

Rory

Well, it depends on the nutrients you're talking about. We have three primary nutrients, nitrogen, phosphorus and potassium. Most of our potassium is mined up in Canada. Our phosphorus is mined here in North America, some in North Carolina, some in Florida, and some comes from Morocco. But the one they're really talking about, primarily this comes from the Gulf, is nitrogen. Nitrogen is made from natural gas, and of course they make a lot of natural gas over there in the Middle East. So where they... pump the natural gas out of the ground. also have a lot of factories to convert that into nitrogen fertilizer. About 78 % of the air we're breathing is nitrogen, so they combine that with natural gas to make a nitrogen fertilizer.

Travis

And I guess how critical is nitrogen to most fertilizers and most farmers?

Rory

It's one of the three primary ones and if you're short of that your crop's not going to grow as well as you would like it to grow. So you'll have you'll suffer from decreased yields. So yes certainly and if you go to the if somebody goes to Lowe's or Home Depot or somewhere like that to buy a bag of fertilizer and the numbers on it are 10 10 10 that means by weight is 10 % nitrogen 10 % phosphorus and 10 % potassium. So it's one of those big three that people can buy. Yeah, they should be familiar with if they ever buy fertilizer.

Travis

Well, this might be kind of a silly question, but I've always been curious. Why do our plants need fertilizer?

Rory

Well, just like we need good nutrition, plants need good nutrition. And if we don't eat enough, we're going to be malnourished and the same with plants. So our soils tend to be deficient in nutrients in terms of getting maximum growth. If you see forest, forest grows very slowly. Whereas when we're growing our agronomic crops for food, they grow very fast. So if they don't have the available nutrients, they're not going to be able to grow and get that optimum yield.

Travis

So the fertilizer is kind of like the crops taking their vitamins.

Rory

Yeah, like the food pyramid. Something kind of similar, yep.

Travis

Well, if there is a holdup, I guess, with nitrogen, what could the impact of that be on crops?

Rory

Like I said, nitrogen is the one that's most limited and our soils, hold the phosphorus, they hold the potassium very, very strongly. So it's possible your soils already have enough phosphorus and potassium in them based on previous years of application, but nitrogen is very ephemeral. It moves. If it rains, it'll leach. And sometimes it can be changed back into the gas that we're breathing right now. So if you over apply nitrogen in the past, it'll be mostly gone by this year. So nitrogen, of course, is the one that's most ephemeral, is the one that we're struggling with in terms of price at the moment. And I think something like 30 % of global nitrogen fertilizers come out of the Gulf. So it is really important on the scale of the world. We're fairly fortunate here in terms of, since the frackn revolution, our nitrogen production, it had been going down and started going back up again because we have a lot of cheap gas here. And obviously that's the ingredient for nitrogen fertilizer. if we don't get a good source of nitrogen then our crop yields are going to go down. And talking to some farmers recently, they say it's better than the Ukraine war. Obviously the Ukraine war, Europe stopped importing gas from Russia. It was another big supply shock. But they said this time around they're seeing increased prices. just, not seeing the lack of maybe just being able to find it the way they did at start of the Ukraine war, was that, four years ago.

So yeah, prices are definitely up, but farmers should be able to find it. It's just going to cost more this year.

Travis

Well it being spring and I think about planting things in the spring, it particularly, is this like a time when we need a lot of nitrogen or are there other times during the year when we would need it as well?

Rory

Yes, this is the major time planting season. So farmers are getting ready to plant. It depends on where they are in the US. Some may have started to plant, but it's really just beginning to ramp up now in terms of the planting season starting. And some other fertilizers, you can apply them at different times of year. Nitrogen is very time sensitive because it's so ephemeral. It'll move. So you want to apply a little bit when you plant. And then for something like corn that uses a lot, when it gets to about one to two feet tall over the next month. It'll take up about half the nitrogen of its growing cycle. So it's very important to put the nitrogen out right before it's taken up. So it's not waiting around for some heavy rain to leach out of the ground or something like that. So yeah, this is the critical time of year in terms of farmers purchasing nitrogen. Some of them have locked in prices in advance, which is common for them to do, but maybe over half of them have and maybe about a third of them haven't. I'm grasping at numbers here, but some of them have for the early season for planting. It's that second application, the side dress application, where they may be a little more price sensitive for the nitrogen application to something like corn. But again, not all crops need nitrogen. We have legumes that will take the nitrogen from the atmosphere. So the common ones are like soybeans, the biggest one in the US, where they don't need nitrogen fertilizer. Farmers can switch from corn to soybeans, but then if everybody does that, the price of soybeans will go down. So it's always a balancing act that farmers have to play.

Travis

Well, I was talking to my to my father-in-law over the weekend actually and he spent some time some of his families from Eastern, Virginia actually Eastern North Carolina and they had some farms there and he just you know always tells me stories about growing up working on the farm during the summers and stuff like that and he mentioned the night that what they often would use or someone there would use was actually ⁓ Chicken poop because they said he said it had a lot of nitrogen in it. So I'm curious is, are alternatives like that possibly if we get into a bind for specifically nitrogen?

Rory

Manure is a great source of nutrients. The only issue with it is there isn't enough of it compared to the cropland. So if we take all of the manure and spread it evenly across the cropland, we're not going to get nearly enough in the way of nutrients. In some areas, poultry litter tends to be produced in certain geographic areas because it's vertically integrated. You'll have the large poultry companies that have got the feed mill, the slaughterhouse and all the chicken houses close to that. in some areas, such as the Shenandoah Valley of Virginia and the Eastern Shore, we have concentrated areas where we have a lot of poultry. And in those areas, there should be, or there may be enough nutrients in the manure, but in other areas, they're too far from those poultry houses and of course, it costs to transport. So if you can find it, it's a great nutrient. There just isn't enough of it to go around.

Travis

Yeah, I think you used probably a more kind word than I did for it. But it was fascinating that he immediately made that connection to a story of when he was a kid and some stuff happened there. So it sounds like that, I mean, maybe that there's a hot market for that if you do in fact, or raising chickens, maybe that's something to think about. I'm I know a lot of the work that you do at Virginia Tech related to soil, does all soil need the same fertilizer? ⁓

Rory

No, no, all soil doesn't need the same fertilizer. I actually supervise the soil testing lab here. So whether you're a homeowner or a farmer, you can submit a soil sample to the Virginia Tech soil testing lab. There are also some private ones out there. It doesn't matter if you use Virginia Tech or another one.

If you soil test and follow the recommendation, you're doing a good job. But what we do, we measure how much phosphorus and potassium is in the soil. So if you've applied a lot in the past, that will show up. And if you've applied a lot in the past, you might not need to apply any more. Nitrogen, like I said, it's ephemeral. So if you've over applied last year, or there's really not going to be much left from last year. So nitrogen application is, we give a recommendation for fertilizer based on what you're going to grow.

So phosphorus and potassium, we measure how much is in the soil. If there's enough, you don't need to apply anymore. With nitrogen is all based on what crop you're going to grow. Something like corn will use quite a lot. It uses about one pound of nitrogen per bushel that you're going to yield. Something like soybeans, you don't need any nitrogen. You just need your phosphorus and potassium. And don't forget about lime. Lime keeps the pH. You want something close to neutral. Very acidic soils, you can get aluminum toxicity or...It makes some of the other micronutrients less available. So, lime's cheap compared to fertilizer. So, make sure you keep your soil pH correct as well. yeah, soil test, send it to it. Take a soil sample, send it to a soil testing lab and you'll get an accurate fertilizer recommendation based on the history of the site, which shows up in the soil test and also what you're going to grow. Some plants need different nutrient combinations than others.

Travis

at my house, I don't really do a lot with the fertilizer or the garden. I do what I'm told to do in that area, but it sounds like that maybe some of us might even be putting some things out that our soil doesn't even need and maybe need some different things.

Rory

Yes, it was a constant thing with me with my father. He applied 10, 10, 10 fertilizer every year to his yard. And I'm saying, Dad, you've been applying it every year. You've probably over applied the phosphorus. Just take a soil test. You can probably save some money. And his attitude was, well, it works and it doesn't cost me much. So why would I change it? So when we look at the soils that come through the soil testing labs, farmers are doing a much better job than homeowners.

Sometimes I hear people talking about farmers if they're over applying nutrients causing pollution, but I normally hear from farmers the other way around. It's like, can I cut back? These are really expensive inputs and I would like to cut back on how much I apply. What will happen if I cut back a little bit on this nutrient or that nutrient? I'm the same for pesticides. Whereas homeowners, they generally buy a bag of fertilizer and apply it to their yard. They don't know the percentage of an acre they've had. They don't soil test, follow recommendations. So some of our Homeowner samples come in with strange pHs and excess nutrient concentrations relative to what we see from farmers.

Travis

Well, I guess before we kind of wind this thing down, what is your favorite thing to grow? I guess if you grow something, I guess I'm assuming that you try to grow some stuff because you, but maybe you just work in this and you don't want to take your work home. But I guess do you grow? And if you do grow things, what's your favorite thing to grow?

Rory

I do have a small vegetable garden and after trying a lot of different vegetables I've narrowed it down to tomatoes. There's just nothing like a vine ripe tomato. It's so much better than what you buy in the store. I like a few peppers and zucchini. You can't go wrong with zucchini. They're easy to grow and very abundant.

Travis

Now is there any specific nutrient that they need to grow their best?

Rory

No, just it's the same as everything else. It's the soil test and follow the recommendation. If you've got a vegetable garden, we have a recommendation for that. Keep the soil pH about right and follow the recommendation. And if you want any help, you can go to your local extension office. There's also the master gardeners. They help homeowners measure their yard, work out how many square feet they have, take them through the soil submission and how to convert the fertilizer recommendation into how many pounds of a specific fertilizer you would have to apply.

Travis

Well, that's awesome. That's awesome that there's not only this type of information out there, but it sounds like there's also a lot of help just in navigating all this information.

Rory

Yes there certainly is. 75 % of my time is attributable to extension so what I do is I try and help the public and we have extension agents spread out through the through the state and then on campus here or some of our research stations we have people like me they're very specialize. The agents have a wide knowledge on pesticides and fertilizer and other things. My focus is just nutrients. So if they have any question at all about soil fertility, they can come to me for questions.

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Travis

And thanks to Roy for helping us better understand fertilizer and some of the impacts of global conflicts on it. If you or someone you know would make for a great curious conversation, email me at traviskw at vt.edu. I'm Travis Williams and this has been Virginia Tech's Curious Conversations.