David Montgomery is a geomorphologist who looks at the processes shaping Earth’s surface and how they affect ecological systems — and human societies. He has studied everything from the ways that landslides and glaciers influence the height of mountain ranges to the way that soils have shaped human civilizations, both now and in the past. He has worked in mountain ranges throughout the world, from the Cascades in the Pacific Northwest to the Andes in South America and Tibet, and the Himalaya in Central Asia.
In addition to his academic work, Montgomery has written a number of popular science books, three of which won the Washington State Book Award. He is an elected fellow of the American Geophysical Union and has received many awards throughout his career, including a MacArthur Fellowship and the Vega Medal.
In this episode, Montgomery discusses his career trajectory, which began with a fascination for maps as a child and led him to become a geomorphologist studying Earth’s surface features. He describes his transition from biology to geology during college.
Montgomery also shares insights from his research on soil erosion and its impact on civilizations, as well as his collaboration with his wife, Anne Biklé, on books about soil health and regenerative farming. Listen to learn more about the importance of soil microbiology for crop health and human nutrition. You can also catch some music by his band, Big Dirt.
Related: UW Magazine published this recent feature on Montgomery.
Full episode transcript
Sarah Smith
From the University of Washington College of the environment. This is Field Sound.
00;00;21;21 – 00;01;06;26
Sarah Smith
The evolution of Earth’s landscapes are measured on a geologic time scale. Since massive changes measured in millions of years. Looking for unseen processes shape our planet. The unseen processes can also shape a scientist’s evolution. David Montgomery’s path to science came with some unexpected twists and turns, He can now be described as an award winning geologist, MacArthur fellow and professor in the Department of Earth and Space Sciences here at the University of Washington College of the environment.
00;01;06;28 – 00;01;26;26
Sarah Smith
Montgomery’s work centers on geomorphology, the study of physical features of the surface of the Earth, their origin and evolution.
David Montgomery
You know, it’s kind of the here and now of geology. It’s what shapes the surface of the Earth. So think about how rivers cut their banks or make pools that salmon can use. Or someone asks you, why are the Cascades as high as they are?
00;01;26;27 – 00;01;52;01
David Montgomery
You know, a geomorphologist would understand about the processes that sculpt the land. And so it’s people who study the evolution of the landscape. Continental collisions lead to big mountain ranges and things like that, but also things like, you know, how farmers influence the erosion on their fields and how that feeds back onto the stability of food supplies for people, or how land use practices influence the suitability of rivers downstream for hosting salmon populations.
00;01;52;07 – 00;02;15;26
David Montgomery
You know, we live on the surface of the Earth. Our resources are mostly acquired at or near the surface of the Earth, and it’s an incredibly dynamic environment that, as far as we know so far, is pretty unique in this universe. One of the things I really like about geomorphology as a field is that it’s fundamentally interdisciplinary, because to understand what shapes the surface of the earth, you gotta know some geology, you can know some physics, I know some math, all that kind of stuff.
00;02;16;03 – 00;02;37;05
David Montgomery
Chemistry you need to know understand the biology, whether you’re looking at how trees, you know, help prop up mountain ranges, or how when they fall over, the physics of flow around them influences the pools in a river system. So you’ve really got to understand the ecology, the geology, know something about atmospheric sciences. It’s fundamentally interdisciplinary. And to me, that makes it, you know, intriguing and exciting.
00;02;37;11 – 00;02;53;17
David Montgomery
You know, I think one of the reasons I am probably a geomorphologist today is I was fascinated with maps as a kid. And when you think about how we portray landscapes, you know, in my age demographic, we used to do it on maps. And so I would be the navigator on family trips. You know, it was hard for me to get lost.
00;02;53;17 – 00;03;13;23
David Montgomery
I could triangulate things. I’ve got good spatial reasoning. And so I practiced without knowing it, as a kid in those regards. But when I started college, I wanted to be a biologist. And that’s entirely the fault of my high school biology teacher who’s absolutely wonderful teacher who, you know, totally turned me on to like, questions like, you know, how does a redwood tree get water from its roots to its crown?
00;03;14;00 – 00;03;32;07
David Montgomery
That’s a hell of a pump. How does that work? Those kind of questions are the things I was fascinated with going into college. I wanted to be a theoretical ecologist because I thought that would be cool. I knew some math. I wanted understand natural systems, and I got really turned off by the program I was in. Why? Well, at the university.
00;03;32;12 – 00;04;00;25
David Montgomery
that I was at as an undergraduate, most of the people involved in the undergraduate biology program wanted to be a doctors. They were a pre-medical, a people, and I wanted to understand how nature work. There are two of us who, in a class of 400 that were really interested in the ecology of biology, and I ended up dropping out of college because I was very discouraged, and I took a year off, grew up a lot, had a lot of great experiences and came back, really still very interested in the sciences, but much more interested in geology.
00;04;00;27 – 00;04;23;13
David Montgomery
One of the last classes I took before I stopped out, as they call it, where I was an undergraduate, was it was geology 101, Basic Introduction to geology. And there the students collaborated on projects. We went on field trips, you know, the professor who was in his mid-sixties, little older than I am now, would beat all the students up to the top of a mountain, showing them stuff, talking all the way.
00;04;23;13 – 00;04;53;26
David Montgomery
And it was a really collaborative, positive experience in the science, the antithesis of what I experienced as an undergrad biology major. That made a big difference. The joy of actually learning stuff together rather than competing, is was a powerful motivation for getting into the earth sciences and got into geomorphology because one of the most interesting classes I had in the undergraduate geology program, I then went out and after I graduated from college, I played music in the Bay area for a couple of years, but it didn’t go anywhere.
00;04;53;26 – 00;05;15;29
David Montgomery
So it came time to think of, you know, do I keep the day job as a as a grunt level intro geologist for an engineering firm, or do I go back to grad school and I wanted to learn more. So I went back to grad school thinking I was going to get a master’s degree. Decided when I was virtually done with master’s degree that, well, I’m going to stay here longer, I’m going to get a Ph.D. and then I end up getting a job, out of grad school up here at UW.
00;05;15;29 – 00;05;55;22
David Montgomery
And I’ve worked on a whole series of different kinds of things, all related to geomorphology in one way or another.
Sarah Smith
Over the years, the principles of collaboration, connection and community were formative in Montgomery’s path. Montgomery now paces ideas forward with his own students.
David Montgomery
One of the things that I think about now as a professor is as I look back at my own career and think about, you know, just how huge an influence certain people had on me at certain points with gentle nudges, you know, in terms of either introducing me to a new field or exciting me about a new field that I then went off and chased, or even recommending that I apply for
00;05;55;22 – 00;06;22;20
David Montgomery
certain jobs or do certain things. That kind of what I call soft mentoring was incredibly influential, and so I carry that around now in my head thinking about that when they interact with students here. and that’s actually one of the fun. There’s a lot of not fun parts of the job, but that’s one of the really fun parts is to think that, you know, you could actually help people figure out kind of what they want to do in this world and in a positive way.
00;06;22;22 – 00;06;47;09
Sarah Smith
Montgomery is also a popular author. He’s written a series of books related to the human influence on our planet’s health, and how agricultural practices have affected human health and evolution.
David Montgomery
And about 15 years ago, I wrote a book called Dirt The Erosion of Civilizations that looked at it was a history of a river of erosion, and particularly in the last 10,000 years, the agricultural era of human history.
00;06;47;09 – 00;07;07;00
David Montgomery
And it’s a kind of book you might expect a geologist to write about soil, right? Sort of to backwards looking book about how erosion has shaped the unfolding of history and the course and fate of civilizations in the past. And I got into it because, you know, in my, life as a geomorphologist, I study erosion because that’s what shapes the surface of the earth.
00;07;07;00 – 00;07;25;24
David Montgomery
So that’s like bread and butter science. that I would do. And the last 10,000 years to a geologist is a really interesting period of time, we call it now. We argue about when the Anthropocene, the human era started, and it’s sometime within the last 10,000 years. Opinions vary, although it’s being dialed in, I think, by various committees around the world.
00;07;25;27 – 00;07;44;20
David Montgomery
but the key thing is, is that in writing that book and researching it, when I thought I was sort of looking into my own field and how it had shaped society, what I ended up doing is writing a book about the history of farming, because that was the real story about how erosion influenced the course and fate of human civilizations, is how people treated their land.
00;07;44;20 – 00;08;11;29
Davis Montgomery
To make the story as brief as possible, affected how the land then treated their descendants, and people who degraded their land, impoverished their descendants. And you can still trace the effects of that thousands of years later in certain parts of the world, like Syria or Libya, for example, where we’ve got records of Roman, Roman tax records of Bountiful wheat harvests in places that you could barely grow anything anymore because the soil is literally gone, or the topsoil is literally gone to be more technically correct.
00;08;12;04 – 00;08;31;25
David Montgomery
And that got me interested in soil and soil health.
Sarah Smith
Montgomery has also coauthored books with his wife Anne Biklé, a biologist, writer, and talented gardener.
David Montgomery
When I was finishing writing dirt, we bought a house, around near Green Lake. When I got tenure here, I finished writing dirt, with, okay, we can scrape together, buy a house.
00;08;31;28 – 00;08;49;17
David Montgomery
And we thought we were going to build a garden. What we did build a garden. The garden. That. And it always lusted after and wanted, And we could never afford as students, but we had crappy soil, it turns out. And so she worked for literally a decade restoring the soil in our yard. And we started to see the results of that.
00;08;49;19 – 00;09;16;28
David Montgomery
About the time that the dirt book was published, that it was like, oh, here I’m writing about the degradation of soil and past societies. And here my wife is, are like completely reversed the story right in my own yard, you know. So Anne and I wrote a book called The Hidden Half of Nature that got into the mycorrhizal fungi, the life in the soil, the other the symbiotic, the mutually beneficial relationships that organisms in the soil have with plant hosts, and how that shapes soil fertility.
00;09;17;00 – 00;09;41;26
David Montgomery
It was sort of all the stuff that we hadn’t been taught in grad school about soils. When we took soil science classes, that the biology was actually central to its productivity, and that much of that biology was invisible. The hidden half of nature, you know, below ground and microscopic. And that really opened windows on thinking about how the mechanism for how to reverse the soil degradation I was writing about.
00;09;41;26 – 00;10;08;24
David Montgomery
And dirt might come into play in that agriculture because, you know, if we could restore the life in the soil on farms, it could catalyze relationships that could not only maintain productivity and fertility using less agrochemicals, less diesel, less pesticides, but could also, it turns out, enhance the nutritional quality of food. But we didn’t know that at the time.
00;10;08;27 – 00;10;31;25
David Montgomery
So when we wrote The Hidden Half of Nature, that then left us with the question, you know, based really on following what an had done in our yard and going, wow, we can restore soil actually fast in decades. It doesn’t take centuries. It could be done on policy relevant timescales, which to me was a complete revelation, because if you go to soil science textbooks, what you’ll find is that it takes, you know, 500,000 years to make an inch of soil.
00;10;31;27 – 00;10;57;18
David Montgomery
And that’s true if you’re making it from rocks. But if you’ve already got the mineral stuff and it’s just poor soil, you can enhance it and rebuild this fertility in years to decades. And that means that it’s actually feasible to completely turn around the problems I wrote about in dirt. And that’s then what led me to write Growing a Revolution, the third book in our The Soil series, which basically looked at whether or not we can do on farms what and had done to our yards.
00;10;57;20 – 00;11;13;26
David Montgomery
And so I literally took six months of, of time that was funded by it, by a generous gift from a private donors and allowed me to take the time and to travel the world, visiting farmers who had done to the land would and had done to our yard, and asked the question of, can we do this at scale?
00;11;13;29 – 00;11;44;26
David Montgomery
You know, can you do you know, to do it to restore the soil on. And, you know, one lot in Seattle is, is, is is fun, but it’s not like world changing. But what I found was that there’s farmers and subsistence farmers in equatorial Africa, in Central America, large, commodity crop farmers across North America and Canada who had all been very successful at rebuilding very degraded land into very fertile land, and doing it while using, you know, less than half the diesel, less than half the agrochemicals, less than half the fertilizer.
00;11;44;28 – 00;12;09;28
David Montgomery
And then some of them were using virtually none. They were essentially organic farmers, but they wouldn’t call themselves. So I teased them that they were organic ish farmers. And what was what was their secret? They had they had restored their soil using regenerative farming techniques. And it turned. My job was to basically look at these, you know, small, hand labor subsistence farms in Africa and these large mechanized farms in, in North America.
00;12;10;00 – 00;12;44;07
David Montgomery
And ask the question, well, what are the commonalities? You know, what is it? What does it actually take to rebuild the fertility of the land? And that’s where the real interest in farming practices came in, because there was a common recipe of minimal disturbance, keeping living things growing in the ground at all times and growing a diversity of crops, which translates into no till farming, farming without plowing, planting cover crops was always something growing in the ground and rotating crops, not just growing corn and soybeans, but actually growing 5 or 6 crops in the same land over a rotation and thinking about, well, why would that work on small subsistence farms?
00;12;44;07 – 00;13;06;05
David Montgomery
You know, it seemed to be scale and technology and climate and soil and dependent. It was a sort of a universal, higher, higher level, way to think about it. And that tied right back into it. And I wrote about In The Hidden Half of Nature, because it turns out that those things, by not disturbing the ground, by planting cover crops and applying a diversity of crops, you’re creating habitat for soil life.
00;13;06;10 – 00;13;30;26
David Montgomery
You’re feeding soil life, and you’re giving them buddies a community. And that’s a recipe for a vibrant ecosystem, you know, food, shelter and and a community. And you think about, you know, at a human level. That’s what makes us so successful as a species, is that we’ve figured out how to shape our habitat, we know how to grow our food, and we have a diversity of expertise that allows us to achieve more together than any one of us could do individually.
00;13;30;27 – 00;13;51;28
David Montgomery
Soil life is the same and that, to me was a real revelation to every and every summer now and after writing, during a revolution that left and and I with the questions of well, what does it mean to what’s in our food? You know, because we could stop erosion. Great. We could grow food. But what’s in it?
00;13;52;00 – 00;14;17;27
David Montgomery
and that’s where we wrote our most recent book. What? Your food aid, which looks at how those regenerative farming techniques translate into different levels of micronutrients, minerals, things like zinc and copper that we need in our diet and that we can’t get by eating rocks or pennies. You know, it’s just not gonna work. we need plants to eat them first so that we can then get those mineral elements in our diet, or either from the plants or from animals that eat those plants.
00;14;18;03 – 00;14;38;01
David Montgomery
And we essentially pulled together in that book the research that shows why the way we farm influences soil health, how soil health influences crop health, how crop health influences livestock health, and how crop health and livestock health influence human health. In the way that we can see it. There’s fairly clear and solid scientific evidence connecting all the little dots you have to connect along the way.
00;14;38;01 – 00;15;01;24
David Montgomery
So there are things that plants make for their own defense when they get into us. Our bodies are actually capable of using them. For our defense. In writing these books, Montgomery has successfully woven together science that gets the technical seal of approval from his peers and a more digestible explanation that connects the dots for a broader audience on why soil health matters for the earth and ourselves.
00;15;01;26 – 00;15;20;16
David Montgomery
One of the hypotheses we put forward, and what your food aid is, that the way that we farm have has influenced the provisioning of compounds in our food that aren’t considered nutrients because we don’t need them to live, we don’t need them to survive, but that really influence whether or not we thrive. Things that relate to our health.
00;15;20;16 – 00;15;43;18
David Montgomery
So if you think about, you know how a plant eats, you know, we know about photosynthesis, but that’s just getting the carbon, all the other stuff they need, all those minerals. They need to get out of rocks and into their bodies so they can build things like enzymes and complex structures. And you can think about minerals as those specialty pieces and Lego sets where if all you had was little bricks, all the little carbohydrates, you could build really boring things.
00;15;43;21 – 00;16;07;17
David Montgomery
If you had the specialty pieces, you can make weird stuff. And that’s what what things like enzymes and other compounds that the plant bodies and our bodies rely on really use. So where does that all happen? In the soil, where the rocks get broken down and where the microbial life is doing it. And if you look in the human body, in our own gut, we’ve all heard a lot about the microbiome in the last ten years or so.
00;16;07;17 – 00;16;33;02
David Montgomery
And our gut, our gut microbes, and if they’re happy, we’re happy kind of a thing. If you look at the processes that are happening in terms of nutrient acquisition, defense teeing up of whether it’s plant defenses or our immune systems, communication, signaling, the sort of three really important processes that are happening in this two environments. You can go down and check the boxes off of the relationships between microbes in the host organism, in our gut versus out in the soil.
00;16;33;04 – 00;16;57;29
David Montgomery
It’s really similar. The only thing it’s different is that in the soil, it’s happening outside of the plant and in our bodies. We’ve taken the microbes inside of us and given them their own special habitat, whereas the plants are doing it all out in the soil. And that’s what I mean by the sort of inside out. But when you kind of recognize those patterns of like, oh, this is the same system, just inverted, all of a sudden it’s like, oh, crap, that’s how nature works.
00;16;58;01 – 00;17;20;02
David Montgomery
And then it makes you go, oh, well, if we’re farming in a way that works against those relationships, that makes you start thinking about maybe there’s a better way to do it. And that’s what I’m writing about now in the new book, is trying to basically put the case forward for why we need to think about the soil differently in agriculture to be able to sustain both farming and human health over the long run.
00;17;20;02 – 00;17;40;12
David Montgomery
And when I started college as a geology major, well, when I finished college’s geology major, yeah, that was not in my agenda for even thinking or writing about the soil. You know, the long story of how a geologist would end up writing about how farming affects human health. You can kind of connect all the little threads together, but it’s been a fun journey that was completely accidental.
00;17;40;12 – 00;17;59;10
David Montgomery
Like, I was originally going to write one book about soil, and we’re up to four now, and I’m starting to work on a capstone on why we need a new philosophy of agriculture to help guide how we apply the technologies that we develop in the future to the problem of sustainably feeding the world. And I’m a geologist, so when I say sustainably, I mean sustainably.
00;17;59;10 – 00;18;17;09
David Montgomery
I mean, I mean for centuries, if not millennia. One of the cool things about this profession is that you’ve got the freedom to follow a thread and see where it leads you. and it’s been a very interesting journey diving into the soil stuff. And it’s not about to stop.
00;18;17;12 – 00;18;39;21
Sarah Smith
When he’s not busy writing or gardening or working as a geologist, what else is David Montgomery up to?
David Montgomery
If you’re a student and listening to this, I teach a seminar, usually in the spring, where we read a few of these books and have a discussion section. It’s always a great class, kind of freewheeling, but one of those really fun classes encourage people to sign up for, should they be interested in that.
00;18;39;23 – 00;18;51;16
David Montgomery
And if anybody is interested in music, I’m the guitarist for a band called Big Dirt that has about six albums out or up on Spotify. Just look us up Big Dirt on Spotify.
00;18;51;18 – 00;18;55;16
00;18;55;18 – 00;19;30;24
Sarah Smith
I’d like to thank my guest, David Montgomery, for joining us today. Go and you can learn more about David’s work, his books and his band Big Dirt on our website at environment uw.edu. We’re offering the same from all of us. Field Sound . Thanks for listening. See you next time.
