Dust To Eat

Published Oct 17, 2023

Jess digs into the science of soils and farming in the century of climate change with Dr. Rick Cruse of Iowa State University.


“Dust to eat, and dust to breathe and dust to drink. Dust in the beds and in the flour bin, on dishes and walls and windows, in hair and eyes and ears and teeth and throats, to say nothing of the heaped up accumulation on floors and window sills after one of the bad days.

Everything now depends on whether a definite change of moisture conditions occurs in time for people to sow wheat for 1936. The ‘suitcase farmers’ – that is insurance agents, preachers, real estate men, and so forth, from cities near or far – have bet thousands of dollars upon rain, in other words, have hired the preparation of large areas of land all around us which no longer represent the idea of homes at all, but just parts of a potential factory for the low-cost production of wheat – if it rains.”

Those words are from the book, “Letters from the Dust Bowl” by Oklahoma farmer Caroline Henderson. They reach across the decades, a nightmare vision from our nation’s catastrophic years in the chokehold of a combination of natural and human-made conditions that pushed our country to the brink of collapse. The arrival of settlers in the Midwest and west heralded the destruction of over one hundred million acres of prairie grass. These delicately balanced ecosystems were obliterated under the blade of the plow and when fallow fields and naked dirt met drought and wind, the result was walls of choking black dust that pummeled the Great Plains, and even reached as far east as the nation’s capitol.

This perfect storm of disaster was solved in time, and it took the combined efforts of scientists, government officials, and individual farmers and communities working together to change the face of farming in the 20th century. With our current climate crisis, we’re already seeing mass destruction caused by fires, floods, tornadoes, droughts, heat waves, and cold snaps.

Of course, as we’ve already learned, we can’t eat dust.

I’m your host Jess Phoenix, and this is science.

Jess: I'm excited to welcome Dr. Rick Cruse of Iowa State University to the show. Dr. Cruse is a professor of agronomy and serves as the director of the Iowa Water Center. His research looks at soil erosion, soil management, and the physical properties of soil, as well as issues around water quality. Thanks for being here, Rick.

Dr. Cruse: You know more about me than I do, so that's kinda scary, to begin with. But, yeah, we'll go with it.

Jess: We do our research here at Union of Concerned Scientists. Can you tell me what initially drew you to your research?

Dr. Cruse: I started in fisheries while at wildlife biology, love the outdoors, and that was as an undergraduate. And a guy I roomed with in college said, "Get out of the field." He was getting a master's degree. He says, "There's no jobs." So, I did, and I shopped around, and I thought, you know, in an agricultural area, I grew up in Iowa, soils and the opportunity to manage those may give us an opportunity to affect that population of wildlife critters that I was so enthralled with at that time, so I did. Well, that doesn't answer your question yet about how I got engaged with the area that I'm working in. The areas associated with sustainability, and that includes sustainability of the waters that these fish and deer, pheasants, all the habitat things were being damaged by poor use of the soil resource base.

And one of the greatest negative impacts associated with that is soil erosion. And I started trying to connect some dots. You know, I could see that the practices that were targeted for controlling soil erosion, improving soil health, improving soil quality were those that oftentimes favored that wildlife population that I was so enthralled with. So, that, and then, you know, money also helps attract activity. And when there were resources to work in this, you know, that was kind of cool. We're driving down the road with John Laflen, who is a kind of a godfather in the soil erosion area. He's passed now. But I asked John, "I just watched a weather report." This is about 2000. "It showed rainfall estimates using radar and understanding some things about soil erosion, what causes it, you know, heavy rain, slopes, soil types, crops, whatever." I said, "John," I said, "Why couldn't we use that type of information and actually estimate soil erosion across the whole state of Iowa?" He sat there in his car and looked at me kind of funny. He slipped forward on his seat. He says, "We can." So, at that point in time, we started building a team that's now called the Daily Erosion Project. And I've had that group together for 20 years now and still riding that horse.

Jess: The introduction to this episode is about the Dust Bowl, because I found that completely fascinating when I read a book called "The Worst Hard Time" about it. And so, we know that the removal of native vegetation and resulting loss of topsoil via erosion helped to create the conditions that the U.S. experienced during the Dust Bowl. And then, scientists, the government, and local farmers worked together to solve the problem and help stop the Dust Bowl from continuing. So, can you kind of give us a state of the soil today?

Dr. Cruse: In general, soils are degrading, which means that the condition is still going downhill. Now, understand there are areas, there are farms, there are locations where the opposite is true. You know, I talk to people a lot about a bell-shaped curve, which is simply a frequency distribution. I think most people understand on one end of that curve, we have farmers. I'm talking about farmers and their attitudes towards conservation. We have individuals that will literally die to do the right thing. They're going to use whatever practices are necessary to improve their soil, soil health, sustainability, and longevity of that farm. On the other end of that spectrum, you have individuals that seemingly could care less. You won't find a stitch of green in their field other than in our part of the world, corn or soybeans. And, you know, stuff is going south on us in those areas. And then, we got a variety of people in the middle that understand the importance of soil health, soil quality. Okay. So, some parts of your field may be getting better, other parts of the field, the sloping areas, may be getting poor. There's a cultural dynamic associated with this too, Jess.

And that involves land ownership. You know, let's step away from land. I have a hunting buddy that tells me, he says, "Rick, I don't understand anything about agriculture, but I understand there's nothing that starts faster, stops quicker, or corners harder than a rented car." When it comes to land, I mean, we say the same thing about apartment ownership, or house apartment renting, or house ownership. When it comes to farmland, I've had multiple farmers tell me, “On my own land, conservation practices are an investment. On my rented land, they're a cost.” Doesn't mean that every farmer that rents land is doing things that's not favorable, but most of 'em will tell you the incentive to do the type of thing that we're talking about to improve the soil condition for the next year or the next year, or the next year is lost if you don't know you're gonna farm that land for multiple years.

Jess: You blow my mind anyway, talking about rented land, that isn't something that I think most of us city dwellers really have to even reckon with. So, is that very common?

Dr. Cruse: In Iowa, the majority is rented. The majority of land, cropland is farmed by people that do not own the land for somewhere around 55% to 60%, actually.

Jess: Whoa. Okay. Okay.

Dr. Cruse: And another component of this too often is a bidding war. Whoever's willing to pay the most has the opportunity to farm the land. Now, if you and I are in a bidding war, and there are some places they have rental auction. The highest bidder actually in an exchange gets to rent the land. As I bid higher and higher, what's the first thing I'm gonna take out of my operation? Things that don't return the dollar to me, and typically that's conservation practices, at least not on the short term.

Jess: That's absolutely fascinating. So, of course, I wanna connect this big picture again. So, how is climate change contributing to the current conditions that farmers are reckoning with?

Dr. Cruse: Well, the first thing is that too many farmers still want to deny that climate change is real, even though they understand... And that's not all of 'em. That's not all of 'em at all. Every farmer is different. The Iowa Farm Bureau will tell you every farmer is different, but for different reasons. But it's true. Okay. We've got some farmers out there that are champions for the climate change thing and are forward-thinking, really, really great people. Okay, so how is it impacting? The biggest impact at this point in time are the inundation rains that we see popping up and occurring in different places. People have not, farmers have not in the past experienced an 8 or 10-inch-rain. You know, several decades ago, several, three, four, you know, when I was a kid, or at least close to a kid, you know, a 4-inch-rain was a big deal. Now, you can almost double that with some of the rains we're seeing. So, that in many minds is opening some doors relative to what's happening. And the impact of those rainstorms is huge in the areas where they're falling, especially if it's earlier in the season before you have complete canopy cover. Another facet of climate change that is affecting everybody, and whether they accept it or not as part of climate change, is the growing seasons are getting longer. We're planting corn and soybeans earlier and have the opportunity to harvest later, although the maturity time is still somewhat like it was before.

So, the number of frost-free days is increasing. The dew point temperature, which means humidity is increasing. The heavy rains have a big impact on soil loss. Rising temperatures increase the rate of chemical reaction in the soil. And the chemical reaction we're talking about here is oxidation. Well, that's academic speak for organic matter decomposes more rapidly. You know, the warmer the fire, the faster things burn. Well, the warmer the soil, the more rapid the organic matter is lost. There’s a couple things that are having an impact. As climate changes, the crops that are being grown, that also will change the amount of organic material that can be deposited and be retained in soils. There’s one other thing I'd like to mention about this. It's a statement that Pete Noack made, and it was about biology more than soils, but I think it applies to soils too.

You know, he told me, he says, "Rick," he says, "Always remember, biology is not limited by averages. It's limited by extremes. And same thing happens relative to soil degradation. That average conditions don't have an impact." When I ask that, I say when we see what is the average rainfall in a given area for a year, if that average is creeping up or down, that's not a big deal. But if embedded within that average change, you see these infrequent, highly erosive, high-intense rainstorms, and that's what we're seeing more frequently. That has a much bigger impact than just looking at that average. It's creeping up.

Jess: You know, you mentioned that there are a lot of folks in the farming world who don't believe in climate change. So, are you seeing the kind of collaboration between science, government, and agrarian communities that's happened in the past, or are they leaning more towards other methods of solving their problems that are a little bit more siloed?

Dr. Cruse: I think the community approach is gaining some traction. Misery loves company and creativity in the farm world. The term climate resilience is getting some traction. That's different than climate change, using systems or approaches that will allow cropping systems to be resilient when experiencing weather stress or climate stress. So, yeah, we see some more cooperation occurring in that area, people especially trying to target use of water. You know, we're talking soils, but to be quite honest, a plant doesn't need soil. We can grow plants hydroponically. What soil does, it's the reservoir for the nutrients that the plant has to have, and it's the reservoir for water that plants must take up.

So, anyway, the interest in soil health, interest in improving soil conditions, even though I said previously, you know, we're degrading, we're seeing more and more interest, inquisitive farmers about, you know, what can we do? This water thing, they understand better than any of us that if they can add an additional inch of water for their crops to use, they will benefit. I talk to farmers and I ask them, you know, we talk about the water thing, and they said, "Hell, there's nothing we can do." I said, "That's not true." You take, especially look at your sloping areas, water that runs off is not available. If you cover crop those areas or use some practices that improve your soil conditions so that the rain that falls can infiltrate, that's money in your pocket.

Jess: Quick side note, because I'm sure that there are many folks who are our listeners who know what the term cover crop means, but can you explain what a cover crop is versus a non-cover crop?

Dr. Cruse: Cover crops, from the time that you harvest until the next crop is planted and it germinates, there's nothing in that soil, nothing, no living crop at all. Cover crops are crops that are planted low-value crops in terms of...and you don't get any commodities out of them. But they're a planted crop that grows after the main crop is harvested, it grows until it gets so dang cold, it can't grow anymore. And if it is a type of species that will overwinter, it will start growing again in spring. So, people often look at the top of the plant and think, "Whoa, that's great." In reality, the soil benefits almost exclusively from the roots of those cover crops. So, anyway, the question was cover crop. So, it is a crop that fills that open time space between harvest and planting of the next crop.

Jess: Great. I think that makes it super clear, especially for folks who, like, have never thought about farming at all, which is, you know, in our modern world, that's fairly common. What are you personally most excited about in the soil science and agrarian world right now?

Dr. Cruse: Well, there are a couple things. The greatest positive thing is we're improving our understanding of the relationship between water and where water exists in agricultural areas and soil itself. As I mentioned, water drives, water is the big animal in the room. Now, where are we coming from water? We've talked about irrigation a little bit, but I wanna talk about areas of the world in the Midwest where the water table is sufficiently close to the soil surface that crop roots can actually extract or use some of that water to buffer any water shortages they may have during the year. And if you have corn and bean roots, they typically can extend far enough down, you know, 4, 5, 6 feet that they can access this water in some locations. Now, I've mentioned before this study where we find areas and fields that are consistently high yield year after year after year. And in my mind, and this is a hypothesis at this point in time, we haven't done the work. We proposed it. I'm thinking it's access to that water. We can add nitrogen, we can add phosphorus, we can add the other things that are necessary in terms of nutrients for the plant. The thing that we can't control if we're not irrigating and over most of the Midwest we're not, is that water. The areas where the plants are consistently under-yielding suggest to me that there is a water limitation. There may be a fertility limitation of some type, but most farmers have the capacity to adjust fertility. In those areas where crop corn and beans don't have sufficiently deep rooting to have an access to that water source, could we grow something else, alfalfa, some other crop that has a potential to access that water?

If we understand where we have water limitations in our fields, can we manage those soils differently to maximize infiltration? Kinda as have mentioned before, water that runs off isn't available. Crops growing in a position on the field that doesn't have access to subsurface water has to rely on everything that falls outta the sky. And having the capacity and knowing where we don't have this yet, but we're working on mapping this out, where these areas are, should be very informing in terms of how we manage what we manage. And this is kind of exciting to me maybe in a little bit sadistic way. And I don't mean, it is, if we have some farmers that are trying to get into this business, they're willing to manage the bejeebers out of their land area. In other words, if they're willing to go through the work of managing these smaller areas in the field in a way that will maximize their productivity year after year, even though it might be different crops, can they compete with a farmer that has 100-foot booms and, you know, all the big equipment, they're gonna do the same thing from one edge of the field to the other and one end to the other? Might this open up some opportunities?

It's exciting. None of this is proven yet. We're looking at data that exists and think maybe that can be done. The other thing that's exciting, and now I'm getting into, you know, my own little silo, is that our capacity to estimate soil erosion spatially at small timeframes is increasing. You know, where, you know, I mentioned started out about rainfall estimates using radar, now in the system, we have the Daily Erosion Project, we have a rainfall estimate every two minutes for every about one-sixth of a square mile. We use LiDAR to get all of our surface slopes and elevations. We have databases that tell us what crops are being grown, what soils exist. In other words, we have all the information necessary to run these computer models that will give us an estimate of how much soil is actually moving on the landscape. It helps us inform, goes back to the questions you were asking earlier, are soils getting better or getting worse? And if they're getting worse, where are they getting worse? Where do we need to spend the money to improve practices?

Jess: Farming has entered the digital age. And it's just a matter of updating our understanding of what farming really is these days. So, along that kind of a line of, you know, what we need to think about to be truly forward-thinking and resilient, what can the government do to help incentivize farmers to conserve, particularly I think in the case of if you have got rented land? And should the government be doing something?

Dr. Cruse: You know, I think incentivized conservation practices, I mean, that's the best thing we can do. You know, it's easy for me to say, "Make rules, regulate." And in my mind, honestly, that's the only way we're gonna solve some of these issues. And I've given talks. I talk to a lot of farmers, and I've given talks multiple times. I've had farmers in amongst other farmers say, "We need more rules." I say, "What do you mean? Do you wanna be regulated?" "No." And they'll mention the name, farms into the ditch, "Neighbor farms into the ditch. There's no grass waterways. I cannot compete with them on the short run. If we have to farm the same way to conserve soil, I'm better than they're, and I can do what needs to be done. But on the short run, I simply can't." They're really distraught about that.

You have another farmer, a farmer's actually a nephew. He's got 20 different landlords, a big operator. And I asked him all the time, I said, "Mike," I said, "If you had to grow cover crops, what would be your reaction?" He says, "I don't mind, as long as everybody else has to." So, it's a level playing field. It's really, really difficult, though, to create any type of a farm program that's equally fair, not program, but rules for the renter, for the owner, for the individual in Iowa versus Kansas. If we were to invoke a law, but you have to have cover crops in Iowa, it will not work because that puts the people here at the short-term disadvantage to those in Illinois if they don't. So, in my world, and I could get shot when I walk out of the building, if the true goal priority is to sustain the soil resource, it has to be done through rules.

You've got some farmers that absolutely do not need rules that do better, but you've got some that absolutely will not. Now, we get the argument back, if we have a limit of how much soil we lose and everybody's gonna farm to that limit, that's not true. There is no evidence that I've seen anywhere that does it. In grad school, you have to have maintained a GPA of 3.25. Does that mean everybody does a 3.25? Absolutely not. And I can go on down the list. So, anyway, I just look at evidence and evidence and evidence to see what might work. And that one is really challenging when we try to do everything on a volunteer basis.

Jess: Basically, it's evidence-based policymaking is what we need, which I am a huge proponent of. So, excellently put, I think. And so, we have one last question to go from here. And because we are the Union of Concerned Scientists, so I ask everybody I have on the show this question, Rick, why are you concerned?

Dr. Cruse: Well, I'll just say sustainability, in general. When I look at what's happening globally, whether you're talking about wars, you know, the big thing to me is water. Water is huge. We are kind of on the precipice of collapse. I can give you an example relative to food production. Forty percent of the world's food is produced on only 18% of the world's agricultural land. What do you suppose is special about that 18%? It's irrigated.

Jess: Really? Okay.

Dr. Cruse: Yes. Yeah. A bundle of that irrigation is coming from aquifers that are being depleted. So, what does that do to the stress put on soils in the dry land part of the world like we have in the Midwest? It's gonna put increased pressure on this soil resource to produce. What does that say relative to the need for conservation? If these soils are degraded, and we lose production capacity in other parts of the world, what's happened with the production capacity in Ukraine? And you suppose that's the only war that's ever gonna happen? I don't think so.

And then, the buffer of climate. Good soils are an insurance policy against crop failure when we have weather stress. Yeah, you know what? Sometimes it's not so bad to be old. I struggle a bit when I try to figure out what my grandkids are gonna live through.

Increasing climate resilience on farms and protecting the future of farming and our food supply means we need major efforts to expand soil-building regenerative farming practices. Right now, USDA incentives and technical assistance programs like the Conservation Stewardship Program help farmers make those changes. The programs are funded by the food and farm bill, and they also received additional money in the Inflation Reduction Act last fall. Unfortunately, the timeframe for the next food and farm bill is undecided. The old one expired September 30, and while this isn’t a crisis yet, but by January the pressure is on. Dysfunction among Republicans in Congress makes predicting what happens next extremely difficult. Thanks to Karen Perry Stillerman and Kyle Ann Sebastian for subject matter expertise, to Brian Middleton, Omari Spears, and Rich Hayes for production help, and to Anthony Eyring for our multimedia magic. Until we chat again, science supporters!