Latest / The Illinois Nutrient Loss Reduction Podcast / Episode 59 | When It Rains, It Pours: Extreme Precipitation & Nutrient Loss
Transcript
- Episode 59 | When It Rains, It Pours: Extreme Precipitation & Nutrient Loss 00:00:06:29 - 00:00:38:19 Todd Gleason This is episode 59 of the Illinois Nutrient Loss Reduction Strategy podcast. When it rains, it pours: extreme precipitation and nutrient loss. I'm University of Illinois Extension's Todd Gleason. You know, in 1914, the Morton Salt Company cleverly converted an 18th century English proverb into a successful marketing slogan. When it rains, it pours. And we generally understand the phrase to mean that when something bad happens, other bad things tend to happen at the same time. 00:00:38:21 - 00:01:07:11 Todd Gleason Among the many increased risks for farming from climate change is an increase in extreme precipitation events, especially in the spring, and with the proverbial when it rains, it pours in mind, a couple of members of the University of Illinois Farm Doc team have written a series of articles exploring the impacts of extreme precipitation events on nutrient loss. The key takeaway, as you'll hear from the authors, is intuitive, simple, and critical. 00:01:07:14 - 00:01:22:08 Todd Gleason When something bad happens (extreme precipitation) the key to minimizing other bad from happening nutrient loss at the same time is to avoid excess nutrients being available to be lost. 00:01:22:10 - 00:01:38:00 Marin Skidmore I'm Marin Skidmore, I'm an assistant professor of agricultural and consumer economics at the University of Illinois. I study the economics of sustainable agriculture, and a lot of my work in that area focuses on nutrient losses in the Midwest. 00:01:38:02 - 00:01:55:29 Jonathan Coppess So Jonathan Coppess, associate professor, gardner associate professor of agricultural policy at the University of Illinois. And, my focus obviously, is on, federal agricultural policy for the most part, which, in years, like the current, stretch has been mostly farm bill dominated. And so that's been a lot of my focus. 00:01:56:01 - 00:02:04:29 Todd Gleason The two of you for the Farm Doc Daily website wrote three articles about nitrogen, phosphorus, nutrient strategies. 00:02:05:02 - 00:02:08:03 Todd Gleason Can you tell me a little bit about them, please? 00:02:08:05 - 00:02:38:01 Marin Skidmore Yes. This work was looking at how extreme precipitation, so heavy rainfall, heavy snow melts, can trigger nutrient losses off of farm fields but also off of other types of landscapes. Developed land as well. And we took essentially a deep dive into one article, as well as a broad overview of the total literature, to see how many more nutrients end up in surface water bodies after we get these heavy precipitation events. 00:02:38:04 - 00:02:45:20 Todd Gleason It will be a question that is asked often when people are reading through this. Why Wisconsin numbers as opposed to Illinois numbers? Can you explain? 00:02:45:23 - 00:03:04:10 Marin Skidmore This is twofold. And one is that I did my PhD and a postdoc in Wisconsin, and because of that, we had access to really excellent data on agriculture in Wisconsin. So of course, in Wisconsin, the primary form of livestock agriculture is dairy. 00:03:04:18 - 00:03:25:22 Marin Skidmore And we knew where every single dairy farm is in Wisconsin, as well as whether that farm is over or under the CAFO threshold. And so we were able to do really, precise and fine grained work on how the nutrient losses happen relative to the type and amount of agriculture in the surrounding region. 00:03:25:28 - 00:03:43:12 Todd Gleason I found it interesting within the articles that, it was important and of note that, the amount of nutrients flowing off often depended on whether there was an urban area, a livestock area, or a cropping area, and all three or any combination thereof. 00:03:43:12 - 00:03:54:08 Todd Gleason We may come back to that. But, Jonathan, I want to return to you. Why should farmers and landowners be concerned about the impact of these extreme precipitation events? 00:03:54:10 - 00:04:04:02 Jonathan Coppess Yeah, well, I think it's one of the things that jumps out of Marin's research and the paper that we aired, the article that she just got published recently, that sort of forms the basis of this. 00:04:04:02 - 00:04:24:24 Jonathan Coppess And and again, the issue is these are nutrients, that are intended for crops on these fields, and they're leaving the field. Right. They're being exported off. So for farmers, for landowners, you have a series of concerns and issues for, you know, for the farmer and the landowner. Obviously, the impacts on potential impacts on yield, on production issues. 00:04:24:27 - 00:04:54:00 Jonathan Coppess But look, these are also getting into public waterways. And that complicates a whole lot of things, for local drinking water, for recreational uses of the waterways all the way down to the Gulf of Mexico when we have that hypoxic dead zone every year. And so there's a series or a variety of sort of reasons why, the loss of nutrients from farm fields are really a big issue in this part of the country, from Wisconsin to Illinois to Iowa, all the way down the Mississippi River basin. 00:04:54:02 - 00:05:16:25 Jonathan Coppess And it's been something that that the state of Illinois and other states in the, in the basin have been working a lot on for the last, you know, 8 to 10 years or more to try to reduce those losses. And so these sort of this sort of research really helps inform a lot of those discussions. And of course, from a policy perspective, it also has a lot of perspective that can be thought about, as we as we looked at the policies. 00:05:16:27 - 00:05:36:09 Todd Gleason Marin I'd like to delve into details just a bit. Could you provide maybe some more insight into the research findings mentioned in those articles, specifically regarding the impacts of extreme precipitation events on nutrient loss in agriculture and how those findings might align with the Illinois nutrient loss Reduction strategy. 00:05:36:11 - 00:05:50:15 Marin Skidmore Absolutely. We were able to look at over a decade of surface water quality readings and daily weather, and so we could link the, on a day that surface water nutrient concentration was measured. 00:05:50:15 - 00:06:18:06 Marin Skidmore We could know how much did it rain that day? How much had it rained for up to two weeks before the water quality was measured. And what we saw is that on days when the nutrient concentration was measured, if it had rained more, the concentration of phosphorus, the concentration of ammonia were both higher. And specifically, if we saw one inch of rain in that day, we would see 50% higher ammonia and phosphorus. 00:06:18:06 - 00:06:39:00 Marin Skidmore And for phosphorus, if it had rained two inches or more, it actually doubled. And then not only that, but for phosphorus, we saw that there were the effects stick around, not just in the week or two after, but all the way until the end of the season. And so years with more days with extreme rain, that is, over an inch of rainfall in a day. 00:06:39:07 - 00:07:12:09 Marin Skidmore Are years that also have higher levels of phosphorus in the surface water at the end of the season. Now, because this is from work from Wisconsin, we can't attribute to, you know, x percent of continued phosphorus or nitrogen in Illinois's water to, to extreme weather. But certainly we would think that the really variable, precipitation we've been seeing in Illinois and the recent years is not helping us in terms of reaching the Illinois nutrient loss reduction strategy goals. 00:07:12:11 - 00:07:17:22 Todd Gleason Can you explain some of the key findings, as are related to the phosphorus losses? 00:07:17:24 - 00:07:36:26 Marin Skidmore We can unpack that doubling of phosphorus on extreme rainfall days and try to tie it back to what's happening on the land at the time of the rainfall. First of all, it's really important to say that a significant portion of the spike in phosphorus cannot be attributed to current activity on the land. 00:07:36:26 - 00:08:01:10 Marin Skidmore It's not attributable to current crop agriculture, current livestock, agriculture, or even, you know, the amount of development on the land. And that points us to the idea that, there are still significant losses of what we call legacy nutrients or nutrients that were spread and applied in years past and are still bound, especially for phosphorus, are still bound to the soil. 00:08:01:12 - 00:08:16:21 Marin Skidmore But we do still also see continued impacts of today's nutrients. And so we see higher phosphorus losses around an extreme rainfall event in areas with more crop agriculture and more livestock agriculture of any scale. 00:08:16:24 - 00:08:33:10 Todd Gleason Also, could you talk a little bit about research that supports the idea that a significant percentage of these nutrient losses occurs during those heavy rainfall events and snowmelt, and explained a little more about that and what it is that's most likely occurring. 00:08:33:13 - 00:08:52:23 Jonathan Coppess And this is what I thought was, fascinating. As we went through Marion's work and research on this is how much it aligns with with our intuition, with common sense. And so, again, these heavy precipitation events, so big rains, you know, the big snow melts when that water is moving. It is taking with it soil and nutrients. 00:08:52:25 - 00:09:14:21 Jonathan Coppess And whether that goes overland in terms of phosphorus in particular and washes, into waterways or it comes out through tiles and that which is a particular issue, obviously a priority issue in Illinois, a little bit more than Wisconsin, which some of the information helps, inform some of the differences, in those nutrient pathways. But it is really just key how we're seeing the numbers back that up. 00:09:14:21 - 00:09:37:20 Jonathan Coppess These are drivers of nutrient loss. And so what that tells us or helps communicate to the farmer is again, you can't control. The farmer has no control over the rain, obviously, if they did that that'd make farming an entirely different operation. So they can't control that. You can't necessarily know, how much that's going to rain or what that event might have, but you can control the sort of circumstances in the field. 00:09:37:22 - 00:10:04:27 Jonathan Coppess And that's a big part of this nutrient loss discussion. Are we on bare ground? Are we applying in the fall? What are the issues that that sort of put the nutrients in place to be lost for heavy rain that can be controlled by the farmer? Or again, from my perspective, where the policy can help support the farmer in making those practice changes and decisions in the field to avoid sort of this pool of nutrients, waiting for a 1 or 2 inch rain to to push them into the waterways. 00:10:05:00 - 00:10:33:19 Todd Gleason There are some things that the Agronomy Handbook, for instance, points to that. Say no, don't do this. For instance, application on frozen ground, simply not something a farmer should do. And the agronomists have been clear at Illinois about that. Applications at other times of the year, timing seem to be important. And the other practices, what kinds of things, do the research say are helping at this point? 00:10:33:19 - 00:10:35:11 Todd Gleason For instance, cover crops? 00:10:35:13 - 00:10:55:19 Jonathan Coppess Well, certainly cover crops, has have been found over and over and over to be very beneficial, both for soil health. But in terms of knocking down or reducing that nutrient loss. And Marion's work and research, again, sort of supports that, that this is a practice that where it is implemented, has real impact on avoiding those nutrient losses. 00:10:55:22 - 00:11:15:20 Jonathan Coppess So again, we see that kind of support. We we and again the best part about this aligns with what you would expect if there is a growing, cereal rye crop in that field during the, you know, the November rains and the January and February snow melts, it's going to hold nutrients, it's going to hold soil, it's going to prevent those losses. 00:11:15:20 - 00:11:33:10 Jonathan Coppess And so it has real value, in trying to address this issue and to some degree can counter the negative impacts of a heavy precipitation event. Having a cover crop there means you're cutting down the loss normally, and you're certainly doing so when it's a big rain or big snow melt. 00:11:33:12 - 00:11:42:14 Todd Gleason Are there practices that are better for phosphorus and practices that are better for nitrogen, and mitigating the losses of each? 00:11:42:16 - 00:12:05:20 Jonathan Coppess Well, I think cover crops probably probably stand as the best in field practice, but anything that has, the ability to hold the soil. So no-till is also extremely important. Right. Because you are you having that residue on the field is going to help hold the soil down and prevent some of the erosion. I think other nutrient management efforts, and I know this is a tough issue with fall applied nitrogen. 00:12:05:20 - 00:12:31:02 Jonathan Coppess And, you know, farmers have a lot of decisions I have to go through in terms of, of, of making that application decision and the timing and everything else. And so certainly are aware that this is not, you know, something just you easily flip a switch on it, but it, it is so critical to think through if we are putting nitrogen on in the fall with putting nutrients on in the fall, they're just they're valuable or the vulnerable to be lost. 00:12:31:02 - 00:12:58:28 Jonathan Coppess They're valuable nutrients, but they're vulnerable. Be lost. And it's and as we watch these weather patterns shift, I mean, just look what we've gone through in the last few weeks from, what, 30 degrees below zero to it's rain for how many days straight now on ground that may be falling out. And it's those sort of those sort of changes that can really drive these losses as well, managing the nutrient practices and things like for applied nitrogen to just get more and more problematic because of this set of issues. 00:12:58:28 - 00:13:24:03 Jonathan Coppess And so as we see these events increase, and as the science says, over and over and over again, as climate change continues to impact us, we're going to see bigger precipitation events. We're probably going to see more of this weird winter weather that just bounces back and forth from deep cold to warming, warming, and raining. We're going to have to think about that, and it's going to increase the challenges around managing nutrient losses. 00:13:24:05 - 00:13:51:17 Todd Gleason Marin, a couple of times during the conversation, it's been mentioned that there is a difference between frozen or bare ground, and large events. So what is the difference when erosion is taking place as opposed to when the water, is simply moving through the profile? So is it nitrogen, nitrogen and nitrate leach? With the water events. 00:13:51:17 - 00:13:57:09 Todd Gleason And then the soil is carrying much different, different kind of load. 00:13:57:11 - 00:14:17:28 Marin Skidmore I'll note that the specific results we're looking at in Wisconsin were entirely, based on surface water quality readings. And so we're really thinking a lot about overland losses. We do see, when it comes to the surface water, we see the biggest losses when there's extreme precipitation in December up until about March. 00:14:17:28 - 00:14:35:12 Marin Skidmore And so that really is coming back to the idea that when you get heavy precipitation, heavy rainfall or snow melt on the bare ground, we're getting really big losses of phosphorus and to some extent still getting large losses as of nitrogen as well. 00:14:35:15 - 00:14:43:07 Jonathan Coppess Yeah. And I just want to add this because in the Marin may have gotten frustrated with me as a coauthor on these farm doc articles because I had the opportunity. 00:14:43:07 - 00:15:04:25 Jonathan Coppess It was a great chance to sort of dig into this type of question and sort of just be reminded of the incredible wealth of research that is out there on this. And so I got into the rabbit hole around phosphorus, which attaches to soil. So anything is moving soil across the surface is taking phosphorus with it. Ammonia, same thing attaches to soil more. 00:15:04:25 - 00:15:34:08 Jonathan Coppess So it moves across the surface. And then it's the nitrate part of the nitrogen fertilizer that, dissolves in water very easily, which is why it feeds the plant through the roots and gets through the soil profile and into tiles. And so this sort of difference and the way the research stacks up and I, I feel like it's a great example of the incredible work that researchers like Marin and, and many others around campus are doing on these topics that is out there that we can then use or apply, use it, and help farmers make decisions. 00:15:34:08 - 00:15:53:12 Jonathan Coppess How policymakers, work on the policy that can help investing in the practices and the farmers who are doing those practices to reduce the losses. And so I do I do feel like there was there was some additional homework I know that we had in this article, really, brought about by the one that that Marin just got published. 00:15:53:15 - 00:16:10:14 Jonathan Coppess But it's fascinating when you think about how the different pathways, those nutrients move. And so then you just start thinking through and, you know, the, the, the frozen ground is going to, is going to wash off. Right. It's going to carry that soil with it. The, the heavy rains and nitrates are going to move through that soil profile. 00:16:10:14 - 00:16:24:14 Jonathan Coppess And again we think of things like cover crops. You're preventing the overland. And you're also absorbing or consuming up, nitrogen that's in the soil. And that's how it plays into this as a, as an attempt to avoid or reduce the losses. 00:16:24:16 - 00:16:32:10 Todd Gleason And while the broader scope of the research is related to nutrient losses and water quality and what's happening with hypoxia. 00:16:32:10 - 00:16:44:23 Todd Gleason Zone, really it's about the practical application of nutrients and how to reserve them on the soil. And the economics of the farm, I suppose. 00:16:44:26 - 00:16:59:07 Marin Skidmore Yes. And we know at the end of the day that cover crops cost money that, you know, and on average, we see that in the first year that a farmer adopts cover crops, they take, profit cut for that. 00:16:59:07 - 00:17:25:21 Marin Skidmore And so there's really no way around the idea that some of these conservation practices take money out of the farmer's pocket. And if we want to see higher adoption of them, because we're, you know, maybe as a society, or as, as the non farming public concerned about what's happening in the water systems, then they're we're not going we cannot expect higher adoption without putting some money towards that. 00:17:25:21 - 00:17:38:05 Marin Skidmore And so I really view this research as being very supportive of of policies and programs that help compensate or support farmers in adoption of the conservation practices. 00:17:38:07 - 00:17:49:05 Todd Gleason Finally, are there practical things that the two of you, after researching these articles and all of the work you've done in the past, think farmers can do or should do on their own fields? 00:17:49:07 - 00:18:18:00 Jonathan Coppess I mean, the practices, right? That's the key. That's the key step here. We got to think through, and in particular, I think through these things as we see these, these weather events changing around us, this precipitate heavy precipitation events. But I agree with Marin like this. This is a this is more than just a farmer. Right. And I think that's one of the sort of takeaways of this series of articles looking at her research that this is not something that we can just simply say, farmer, you go do this and that'll fix it. 00:18:18:02 - 00:18:35:11 Jonathan Coppess And we're seeing that with a nutrient loss reduction strategy and the challenges we are and reducing the nutrients in the waterways. This is not an easy undertaking. It is not as easy as just saying go adopt cover crops. Cover crops have risk. They have costs, they have a series of issues. And so I always come back to this question. 00:18:35:11 - 00:18:55:17 Jonathan Coppess Our policies need to do better. Frankly, this is a public issue. Our public policies and our public funds need to do a better job of helping farmers manage through these sets of costs and risks and challenges that come with the changes and practices we're talking about. And so this to me, I think, feeds into that discussion more and more. 00:18:55:19 - 00:19:20:07 Jonathan Coppess It's another reminder that there's a lot going on here. The legacy nutrients, the different pathways, changing weather patterns, all of that, you know, are not easy and can't maybe just be solved by one quick fix. And we certainly can't expect the farmers to be able to do all of that and address all of those issues. So how do we get more involved? From the producer level to the local drinking water interests? 00:19:20:07 - 00:19:26:02 Jonathan Coppess Like how do you get involved in helping move, the policies forward that help move the practices forward? 00:19:26:09 - 00:19:41:25 Todd Gleason You just heard from Jonathan Coppess, he's an associate professor and the director of the Gardner Agricultural Policy Program here on the Urbana-Champaign campus of the University of Illinois and the colleague of Marin Skidmore, who's an assistant professor in the College of Aces. 00:19:42:02 - 00:20:11:08 Todd Gleason The two have coauthored a series of three articles posted to the Farm Doc daily website at Farm Doc Daily Dot Illinois Dot edu. They're entitled When it Rains, It Pours extreme precipitation and Nutrient laws. You've been listening to the Illinois Nutrient Loss Reduction Strategy podcast. Our program is produced in conjunction with Rachel Curry and Nicole Haverback. And like me, they work for Illinois Extension. 00:20:11:10 - 00:20:12:07 Todd Gleason I'm Todd Gleason.