Prof. Garrison Sposito, soil scientist at UC Berkeley, is an active teacher and researcher. Prof. Sposito describes how soils form, how soil science has matured and talks about the influence of Hans Jenny on his work and life.

Transcript

Speaker 1: Spectrum's next

Speaker 2: [inaudible]

Speaker 3: [inaudible].

Speaker 2: [inaudible].

Speaker 3: Welcome to spectrum the science and technology show on k a l x Berkeley, a biweekly 30 minute program [00:00:30] bringing you interviews featuring bay area scientists and technologists as well as a calendar of local events and news.

Speaker 1: Good afternoon. My name is Brad swift and I'm the host of today's show. Our interview is with Professor Garrison's Pasito, the Betty and Isaac Barsha, chair of Soil Science in the College of natural resources at UC Berkeley. Professor Sposato is an active teacher and researcher. This show is part [00:01:00] one of two parts today. Professor Saucito describes how soils form. He explains how soil science has matured and talks about the influence of Berkeley legend CNE on his work and life. Professor, Gary's Pasito

Speaker 4: come to spectrum. Thank you very much. Glad to be here.

Speaker 1: To start, would you give us a brief overview of soil and how it forms

Speaker 4: in the simplest way to say this soil is the [00:01:30] weathered earth material on the land, the surface of the land. It can extend to fairly great depths depending on how much weathering goes on because weathering is what creates soil. There are two main factors that are involved. One is the percolation of water from rainfall percolates downward and this causes weathering the other, which is critically important and that is the biology that goes on in soil. That is to say the the microbes, [00:02:00] the worms, all of the creatures that live in soil and the roots of plants, which in fact contribute greatly to what happens in the soil to make it soil. Ultimately what happens is that the, what's called the parent material, which is the material from which the soil starts, which could be anything from a cooling volcanic ash material to wind blown dust like it is in China or in the Midwest of the u s or rock material that has come in from somewhere else, from transport [00:02:30] by a river, whatever it is.

Speaker 4: That's some geologic material. And at that point in time when it sits still long enough to have percolating water and creatures start to live in it, that starts it on the way to becoming a soil. What are the various timelines that can be involved in that process? They're long, they're long timelines relative to human standards. So for a soil to form in a way that one would be recognizably say, oh that's a soil. And I'll say in a moment here, [00:03:00] what tells us, oh that's the soil can easily be half a million years to really to see the development. Obviously there are soils that are younger than this, but in general it takes a long time. In California we have soils that are a million years old and we have soils that are 15,000 years old, but they formed slowly by our standards. Now the way that we tell them as soils and not simply some weathered rock or whatever is that they have layering, they're called horizons in the [00:03:30] discipline of soil science.

Speaker 4: This layering is caused by the percolating water, which moves material downward and then deposits it at some point because the water stops percolating. And secondly, the biological creatures are involved in the dissolution and dissolving of the minerals that are in the rock material. So the layering is coming about from both loss of material and accumulation and that layering tells you it's a soil, but it happens slowly. It's a slow process. [00:04:00] How much variation is there worldwide and soils? Quite a lot. What one should know is that there are large classification units of soil which are based on climate and there are 12 of them. For example, a soils that are permanently frozen such as those in the Arctic zone. Those have a certain name, they're called Jelly sols from a French word. That means to freeze soils that are found in the human tropics that are very red [00:04:30] from the iron minerals in them and highly weathered and so forth.

Speaker 4: They're called oxy Sauls and so on. Now within them are sub classifications and the one that corresponds to what a species would be in biology is called a series. There are about more than 20,000 soil series or species in the United States. There are probably upwards of several hundred thousand different soil series worldwide, so the soil series are [00:05:00] mapped so we know where they are and these maps are available online for California and for many parts of the world, it's probably the most important aspect of first getting to know soils is to prepare a map with the series in it. And for that reason, the gates foundation has given a friend of mine, Pedro Sanchez, $20 million to provide a digital soil map of Africa so that we have a, an understanding of all the African soils and this is in conjunction with improving agriculture. [00:05:30] You've got to know the soil characteristics before you can start to do anything with US soil. And this is the first step.

Speaker 5: [inaudible]

Speaker 1: this is spectrum on k a l x Berkeley. I'm talking with Gary's Pasito, a soil scientist at UC Berkeley

Speaker 5: [inaudible]

Speaker 4: in the development of soil science. Have there been [00:06:00] dramatic epics where certain discoveries were made that changed the game, so to speak? Not so much as discoveries as in really large groups of people of a certain kind working towards similar goals. For example, the late 19th century is characterized at a time when earth scientists began to look at soil as useful for study in its own right. And the first things that they did was to try to understand how they formed [00:06:30] as weathered materials and secondly, to begin to try to classify them in some way. That period lasted until, well, it's still ongoing. I suppose, but it was really pushed forward around the turn of the century. And one of the largest names in that field at the time was Eugenie Hilgard for whom Hilgard Hall on the Berkeley campus is named. He was trained as a geologist. He was the state geologists from Mississippi and he was hired here at Berkeley as the second professor [00:07:00] of agriculture.

Speaker 4: The first one, I think he was here only for a couple of years and a lot of people don't know this, but Berkeley began as an a and m campus, agricultural, mechanical, and that's what it was supposed to be. That was it. And the first agriculture professor thought that's what it ought to be. And the regions didn't agree. And so they fired him and they hired Hilgard and heel guard. They said, we want you to understand that you're part of a larger, more general campus than simply agriculture. But it's very important to the state of California [00:07:30] that you develop agricultural emphasis on your work with soil. And one of the first things he did was to go around the state and sampled the soils. And he prepared the first soil map of California, which you can see in Hilgard Hall. But he also helped classify and he also discussed something about how soils form.

Speaker 4: So that was one great group. Then came another group of people who did a lot of their work in the 1930s and forties of the last century. These [00:08:00] people in soil science all came from other disciplines and to a large extent they did. So because of the depression. A good example of sterling Hendricks who was Linus Pauling's, first Grad student at cal tech, he worked on the structure of minerals with Pauling cause that's how Pauling made his first famous set of discoveries and couldn't find a job as a physical chemist. There just wasn't a demand. And at that time, and so he did find a job with a USDA US Department of Agriculture and he spent a whole career [00:08:30] there. He did work on minerals. He was the first one really just show that crystal and minerals existed in soils. People thought it was just sort of stuff. They didn't know what it was. Unfortunately, they developed the tools at cal tech among other places, and palling made great use of these train Hendricks to do this. And then Hendrix got a job with a USDA, began to study plants as well, and actually made a name studying plants. Another example, Albert van Zillow,

Speaker 4: who took a phd under John Lewis here at Berkeley, who was [00:09:00] the Louis Hall's name for him, Fan Solo couldn't get a job except down at the citrus experiment station in Riverside. So he went down there as a chemist, if you know Lewis, his work, he was a great contributor to the branch of physical chemistry called thermodynamics. First thing vast law did was supply it to soils. And that's stood the test of time. It's been very, very useful. And finally I mentioned Han CNE who got his phd in physical chemistry in Zurich. Switzerland couldn't find work anywhere. [00:09:30] Left, immigrated to the u s first to the University of Missouri. And then in 1936, uh, he was able to secure a job up at Berkeley in a plant science unit, uh, teaching some things about souls, but all of these people were in there. Others I could name were quote, forced to come into soil science because it was opportunity.

Speaker 4: Actually one of my own mentors, Royal Rose Street, uh, here at Berkeley, I was a grad student at Berkeley and soil science right in Hilgard Hall. In fact, uh, he was [00:10:00] a student of joke. There's a show called over in Chemistry and Nobel laureate. His thesis was on the properties of liquid hydrogen, and yet he was one of the great soil chemists after the 30s. So these people all turned their skills to, to soil because it was an unknown with respect to the application of exact sciences. And the discipline made huge bounds because of this, because they were so well trained. Actually the depression was one of the best things that ever happened to soil science because it got all these great minds [00:10:30] working. They couldn't find work elsewhere if there had been good times. Who knows? Now finally, there's another one that most people agree was very important and it also relates back to exact sciences.

Speaker 4: And that is all the advances that took place in the latter part of the, of the last century in disciplines such as molecular biology or chemistry at the molecular scale. And to some extent physics. These disciplines were really producing very interesting results. And so for example, [00:11:00] methods of molecular biology were applied in microbiology of soil to characterize the organisms that were living there such as bacteria. And these methods are very important because most of the bacteria and the other tiny organisms in soil cannot be grown in culture, meaning you can't take them out of the soil and grow them in the lab. Probably less than 10% can be grown this way. They're just out there wild in the soil. But the new methods of molecular biology didn't require that they allowed you to fingerprint [00:11:30] literally through the DNA of these organisms who they were. And this was applied to soils and chemistry evolved, all these very fancy techniques for investigating minerals or any solid actually, but minerals in particular and so on.

Speaker 4: So the people in soil science were aware of these things and they took all these methods in and they made great strides with these approaches. Not so much the people, but simply the methodologies made their way into the discipline. And that legacy has gone on for some time now. Right [00:12:00] now we're, we're sort of still taking advantage of it. What I see happening now is the soil scientists are beginning to join with other people in ecology and climate change so that they're part of a larger team, let's say, which is working toward trying to understand how the global system actually functions and what role soil plays in that. I would say that's the next thing that's going on, a kind of cross disciplinary interaction. But these other three epochs everyone recognizes as really important to the advancement of the discipline [00:12:30] and none of them really were created by the discipline itself. They came from happenstance, from circumstance and depression. I mean, you know, I suppose right now there may be, there'll be some very brilliant students who, who might've stayed in chemistry or physics or whatever who will come into soil science. In fact, I know this is true at Berkeley. I'm seeing it happen.

Speaker 3: [inaudible] you are listening to spectrum on k a l x Berkeley. Today's guest [00:13:00] is professor Gary [inaudible]. We are about to talk about his research.

Speaker 4: How about your research? How has it evolved over your career and your studying soil? Actually, I'm an anomaly. It's true that I took a degree here in soil science under a professor named Ken Babcock and another name Roy Overstreet, whom I mentioned earlier in conjunction with joke. [00:13:30] Babcock was my main guiding professor and I did a thesis, uh, which had a very large amount of chemistry and physics in it because I thought that those disciplines should be applied to soil in a very fundamental way. And after I did that, Professor Babcock said, well this is good work, but don't expect to get a job because nobody's interested in this. And he was right and there wasn't any interest in it. People told me, for example, that chemistry doesn't apply to soil [00:14:00] is too complicated. It doesn't work. You can't talk about it this way. So I got a job in the cal state system teaching for nearly a decade.

Speaker 4: And then my major prof told me about Pam Cock, that a professor at Riverside, by that time there was a campus at Riverside, uh, had suddenly dropped dead of a heart attack in his fifties, and they were looking for someone to replace him and they thought they should go in a fundamental direction more so than they had. And so I thought, well, maybe after [00:14:30] 10 years, my time has finally come. So I got a job down there and that worked out pretty well. And then I ultimately transferred up here because I wanted to work on forest is soils. And we have a forestry oriented, uh, unit up here. So I'm, I'm a little bit different from the usual because most people in my field would have come through a kind of agronomic background with let's say a little dash of chemistry and a little dash or biology and so forth.

Speaker 4: And they're generalists or their pathologists. So they're trained in earth science and they look at cell formation. [00:15:00] But I came into it from a very fundamental point of view. So I kind of waited around for my opportunity to, to bring this to bear. And what I'm speaking of really is a molecular scale approach to understanding soil. That's what they thought didn't apply. That was so complicated. You could, and in fact, what has evolved is that actually works out pretty well for the same reason that molecular biology helps medicine. So does them like it or approach to soils help agriculture or any of the other applications [00:15:30] they might not have thought. So at first in either discipline, but in fact it's true. So now what I've seen it evolve is a recognition that is actually useful, uh, over time. And what I do with my work is to try to be ever more molecular using the latest methods from chemistry and physics in that direction to try to understand how soils function.

Speaker 4: And it works out pretty well. And there are tools which, uh, have been developed in those disciplines that can be applied [00:16:00] with some care because we have very heterogeneous material. It's not to a pure substance. So that's where the art comes in and understanding how to use these techniques in ways that won't fool you, but it does work. And so that's it. So it's evolved simply, I get to be the person I want it to be when I was in Grad school by just simply waiting long enough, one of the former deans at the college of Natural Resources here defined a distinguished professor as someone who's outlived his enemies. I wouldn't say that I, that's [00:16:30] a little strong in a, in a bit cynical, but what I would say is that if you believe in what you're doing in your, you persevere, probably you will find that it gains some acceptance. And I'm living proof of the late bloomer theory of, of that sort of thing. And I think most of my colleagues would agree that finally now the world seems to understand that yeah, you can do molecular scale work on something as complicated as a soil.

Speaker 3: You are listening to part one of [00:17:00] a two part interview with Gary [inaudible], a soil scientist at UC Berkeley. The show is spectrum and the station is k a l. X. Berkeley.

Speaker 4: Describe what Hahn's Yannis impact has been on your thinking about soil and how has his work informed yours? Well first of all I mentioned he was trained as a physical chemist and then he found that he wasn't able to get work in Zurich [00:17:30] and so he wanted an academic career. So he came to the u s after he got here, especially in Missouri where he began to just learn the soil. He traveled around Missouri and I've seen the photographs that he's, that he took of the landscapes and began to learn about and think about soils. And Hilgard had already pioneered a little of this in of thinking about what things do come together to form a soil. Obviously you need some earth material to start with. You need organisms, you need time and so on. So Yeni [00:18:00] codified all of this in a book which he published 70 years ago, last year called factors of soil formation.

Speaker 4: And if you look at it from my point of view, what you see is a book about soil, organizing the soil and thinking about the way it formed, the way a physical chemist, and I don't mean the chemistry, I mean the logic of it is like a physical chemist. Actually a person in thermodynamics in physical chemistry would think about it effectively. He was using chemistry as the metaphor in which to place soil science [00:18:30] and it was an astounding book and it's still today read very profitably. We all had benefited from this. That said, Hans [inaudible] was a personal friend of mine and I spoke at his 85th birthday, which was celebrated up here for example, and I traveled with him to field sites and so forth and listened to him talk about soils and so forth. So he clearly had a strong personal influence on me as well.

Speaker 4: He was a very mild mannered person, very thoughtful, very strict in his beliefs. [00:19:00] He was also quite a good artist. He drew all the illustrations for his books himself, which he never mentioned in the book. You wouldn't know except they all look the same and it's, it's him. Art and agriculture were the two big loves of his life and he combined them as best he could in his own work. But he was trained as a physical chemist. So he had that really keen analytical mind and that was clear from his approach to the subject. So I would say he was an influence in the way he influenced every person and soil science through his work. But he also was an influence to me personally because [00:19:30] I could see how this person was living his life and initially doing a lot of hard work to do what would be called the normal science, meaning pushing the data points and doing the things that advanced the technique of the science.

Speaker 4: And then as he got older, he began to think about soils as a resource and their conservation. And he realized that a lot was not being done that should be done. And so he began actively to work toward conservation, working with conservation groups and others [00:20:00] to to help in that. Even though that doesn't require a chemical background for sure to do, but he realized how important it was. So that's what I'm seeing with myself as well. Soil is a resource now is suddenly loomed again is a big deal because of agriculture and because of the world of the world we're living in. And so I see that that's something I should do as well. So he's a role model in that sense.

Speaker 1: This concludes part one of our two part interview with Professor Gary [inaudible]. Tune in two weeks from [00:20:30] today for part two in part two professors placido talks about the interaction with water and soil, chemical and organic inputs that get applied to soil, good stewardship of soil and industrial agriculture. A regular feature

Speaker 6: of spectrum is dimension. A few of the science and technology events happening locally over the next few weeks. Rick [inaudible] and Lisa [inaudible] joined me for the calendar. Our last episode of spectrum featured [00:21:00] Tony Rose and Michelle Houben guy who talked to us about the young makers program that teams up high-schoolers with adult mentors to make things for make affair. You can see their work at the seventh annual bay area maker fair on Saturday the 19th and Sunday the 20th at the San Mateo Event Center one three four six Saratoga drive in San Mateo is like Bernie Man Without the drugs sandstorms and nudity c creative and resourceful people involved with science and technology, engineering, food and arts and craft [00:21:30] one day. Tickets are 27 50 for adults, 1654 soons and $12 for children ages four to 12 check out makerfair.com for more info. That's maker F a I r e e.com

Speaker 7: Saturday May 19th the science at Cau Lecture series presents Professor Ruth Tringham, founder and director of the UC Berkeley multimedia authoring center for teaching in anthropology. She is also the creative director and president [00:22:00] of the Center for digital archeology. Her lecture is titled Reconciling Science and the imagination in the construction of the deep prehistoric past. In the lecture. She will introduce some of the ways in which as an archeologist writer, she is exploring an alternative way of writing about prehistory in which the imagination that conjures up sentient prehistoric actors is entangled with the empirical scientific data of archeological excavations. That's tomorrow at the genetics and plant [00:22:30] biology building room 100 at 11:00 AM

Speaker 6: there is a partial solar eclipse this weekend. You can learn about it and observe it for free at the Lawrence Hall of Science one centennial drive in Berkeley from one to 8:00 PM on Sunday the 20th or view it from Chabot at 10,000 skyline in Oakland for $5 between five and 8:00 PM with the maximum eclipse at 6:32 PM Susan Frankel is presenting in the long now seminar series on Tuesday May 22nd from seven 30 to [00:23:00] 9:00 PM at the cal theater in San Francisco's Fort Mason. Her talk on Eternal Plastic, a love story discusses how plastic now pervades civilization and why its cheapness has made it the basic material of the throwaway culture. One third of all plastic now goes into disposable packaging. It's durability means that any toxic events persist indefinitely in the environment. [inaudible] plastic presents a problem in temporal management of the very long term and the very short term. How do we get the benefits of plastics amazing durability [00:23:30] while reducing its harm from the convenient disposability. Visit [inaudible] dot org for tickets which are $10 now news with Rick and Lisa,

Speaker 7: the May 8th New Scientist magazine reports that recent technological in neuroscience such as functional near infrared spectroscopy allows researchers to watch young baby's brain in their initial encounters with language. Using this technique, Laura and potato and her colleagues have Gallaudet university in Washington d C [00:24:00] discovered a profound difference between babies brought up speaking either one or two languages. Popular theory suggests that babies are born citizens of the world capable of discriminating between the sounds of any language by the time they are a year old. However, they are thought to have lost this ability homing in exclusively on the sounds of their mother tongue. That seemed to be the case with monolinguals, but potato study found that bilingual children still showed increased neural activity in response to completely unfamiliar languages. [00:24:30] At the end of their first year, she found that the bilingual experiences wedges opened the window for learning language.

Speaker 7: Importantly, the children still reached the same linguistic milestones such as their first word at roughly the same time as monolingual babies. Supporting the idea that bilingualism can invigorate rather than hinder a child's development. Bilingualism improves the brains executive system, a broad suite of mental skills that center on the ability to block out irrelevant information [00:25:00] and concentrate on a task at hand. Two languages are constantly competing for attention in the bilingual brain. As a result, whenever bilingual speak, write or listen to the radio, the brain is busy choosing the right word while inhibiting the same term from the other language. It is a considerable test of executive control, just the kind of cognitive workout that is common in many commercial brain training programs, which often require you to ignore distracting information while tackling [00:25:30] a task.

Speaker 6: Nature News reports on an article published on May 4th in science that blonde hair and people from the Solomon Islands in Melanesia evolves independently from Europeans, Stanford geneticists, Carlos Bustamante and his team compared the genomes of 43 blonde and 42 dark haired Solomon Islanders, and revealed that the islanders blonde hair was strongly associated with a single mutation in the t y r p one gene. That gene encodes an enzyme [00:26:00] that influences pigmentation in mice and humans. Several genes are known to contribute to blonde hair coloration in Europeans, but t y r p one is not involved. About one quarter of Solomon Islanders carry the recessive mutation for blonde hair and the mutation accounts for about 30% of blondes in the Solomon Islands. We used to Monte. I thinks that Melanesian mutation might have arisen between 5,000 and 30,000 years ago, but does not know why, nor does he know why. This mechanism differs from that of European blindness

Speaker 7: research [00:26:30] published in April Steele Physical Research Letters, a journal of the American Geophysical Union states that for the first time scientists have captured images of auroras above the giant Ice Planet Uranus. Finding further evidence of just how peculiar a world that distant planet is detected by means of carefully scheduled observations from the Hubble Space Telescope. The newly witnessed Uranian light show consistent of short-lived, faint glowing dots, a world [00:27:00] of difference from the colorful curtains of light that often ring Earth's poles. Auroras are produced in the atmosphere as charged solar wind particles as they accelerate and the magneto sphere and are guided by the magnetic field close to the magnetic poles. That's why the Earth Auroras are found around the high latitudes. While working as a research physicist in the space science lab at UC Berkeley in the early 1980s professor John T. Clark of the Boston University Center for Space Physics Observed [00:27:30] X-ray sources from ground-based telescopes and found the first evidence for an Aurora on Uranus. The voyager to fly by in 1986 confirmed that your readiness was indeed a strange beast. Dennis now a better understanding of your rain. Renesas magnetosphere could help scientists test their theories of how Earth's magnetosphere functions. A crucial question and the effort to develop fusion reactors.

Speaker 6: Science insider reports this week that the newly proposed helium Stewardship Act [00:28:00] of 2012 Senate bill two three seven four would maintain a roughly 15 years supply of helium for federal users, including the holders of research scans. It would also give priority to federally funded researchers in times of shortage. If Congress fails to renew provisions of the 1996 law that is expiring next year, the u s will discontinue sales from the Federal Reserve, which is responsible for 30% of the world's helium. This would be a big problem for manufacturers of semiconductors and microchips as [00:28:30] well as users of magnetic resonance imaging and other cryogenic instruments. Penn State Physics Professor Moses Chan praises the bill testifying that liquid helium may account for up to 40% of the total budget of some grants is only criticism of the current bill is no provision to reward those who recapture helium used in research.

Speaker 2: [inaudible]

Speaker 1: [00:29:00] spectrum podcasts are now available on iTunes university. Go to the calyx website. There's a link to the podcast list in the spectrum show description. The music hard during the show is by Astana David from his album folk and acoustic. It has made available through a creative Commons attribution license 3.0

Speaker 2: [inaudible]

Speaker 1: production assistance has been provided by Rick Karnofsky and Lisa kind of. Yeah. Thank you for listening [00:29:30] to spectrum. If you have comments about the show, please send them to us via email. Our email address is spectrum dot k a l [email protected]

Speaker 2: join us in two weeks at this same time.

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