We Measure The World

Alex received his bachelors in Mathematics & Astrophysics from Oberlin College in 2018. He is currently a Hydrologic Science PhD candidate in the University of Wyoming Plant Physiological Ecology Laboratory. Alex’s research focuses on modeling and measuring the relationship between ecosystem-scale processes and plant physiology, especially as they relate to land management and disturbance. Alex was a 2021 G.A. Harris Fellowship recipient.

Cecilia earned her bachelor’s degree in agronomic engineering from the University of Passo Fundo in Brazil. Cecilia was a recipient of the 2022 G.A. Harris Fellowship sponsored by METER Group. She is currently a PhD candidate in horticultural sciences at the University of Florida, where her focus is on grafted blueberry physiology and production. Her research centers on developing production systems that enhance climate resilience in blueberry crops to address critical global agricultural challenges.

Katie completed her bachelor’s degree in Environmental Science and Technology at Colorado Mesa University, where she focused her studies on water quality and conservation. She is currently pursuing her master’s degree in Environmental Science at Brigham Young University. After that, she hopes to work in the industry for a few years before continuing to her PhD.

Dr. Kathleen (Kate) Smits is a professor at Southern Methodist University’s Lyles School of Engineering and the Solomon Professor for global development. Prior to SMU, she was a professor at the University of Texas at Arlington and associate professor at the Colorado School of Mines and the US Air Force Academy. She earned a bachelor’s degree in environmental engineering from the US Air Force Academy, master’s in Civil Engineering from the University at Texas Austin, and a doctorate in Environmental Science and Engineering from the Colorado School of Mines. She served as a civil and environmental engineering project manager and officer in the US Air Force.

Stephen is a professor in the department of geology at the University of Puerto Rico-Mayagüez. He obtained his bachelors in geology and earth science from the University of North Carolina at Chapel Hill and his PhD in geology from North Carolina State University. He teaches classes in structural geology, geomorphology, and field geology, and his research projects have focused mostly on tropical landslides and landscape evolution, with the funding of such organizations as the NSF, USGS, USDA-NRCS, and NOAA.

Sara received her masters in soils and geochemistry from UC Davis, and her doctorate in engineering sciences from La Pontifícia Universidad Católica de Chile. She is currently assistant professor at that same university, where she teaches courses in environmental biophysics and statistical methods, and soon, geology and soil sciences and soil conservation. Her research centers around lab and field studies related to soil science and environmental studies, with specific focus on soil physics. Her recent interest has been to understand urban soil ecosystem services.

Michael is a senior adjunct research fellow at Griffith University in Queensland, Australia, Founder of Implexx Sense, and Director at Edaphic Scientific, an exclusive distributor of METER Group instruments. He obtained his doctorate in ecology and evolutionary biology from the University of New South Wales. He previously worked as an ecohydrologist at the University of Western Sydney and was a plant physiology senior adjunct research fellow at the University of Queensland. His research interests include plant-water relations and biomass allocation patterns at a macro physiological scale, and experiments with sap flow.

Mason Stahl is the James M. Kenney Assistant Professor of Environmental Engineering in the Department of Geosciences and Environmental Science, Policy and Engineering program. His research spans the fields of hydrogeology, geochemistry and water resources. I study how perturbations to the environment influence elemental cycling and the quality of our water resources. A main focus of my research has been on improving our understanding of the hydrologic and biogeochemical factors that result in the mobilization of naturally occurring arsenic from sediments into groundwater, which is a problem that threatens the health of millions of people around the world. One of the primary goals of my research is to help answer questions about how groundwater and surface water quality will change in response to natural and anthropogenic changes to the environment and what this means for the health of people and the environment.

Ning is a professor of Civil and Environmental Engineering at the Colorado School of Mines. He obtained his bachelor’s in Geotechnical Engineering at Wuhan University of Technology, and both his master’s and doctorate in Civil Engineering at John Hopkins University. He is well-known internationally for his work on stresses in variably saturated porous media, with his primary research interest in seeking common threads among basic soil physical phenomena, including fluid flow, chemical transport, heat transfer, stress, and deformation.

Erin is an Agricultural Engineer and Professor in the Department of Soil and Water Systems at the University of Idaho. He obtained his bachelors in Agricultural Engineering with a Soil and Water Engineering emphasis at Washington State University, and then went on to get his master’s from the University of Minnesota and doctorate from the University of Idaho, both specializing in Hydrologic Measurement and Modeling. Erin’s current research focuses on the management of ecosystems through the combination of field experiments and modeling.

Saul Alarcon is an agronomist for Gradient Crop Yield Solutions with over 30 years of experience in agriculture. As part of the Morning Star Company, his research into plant health has been instrumental in developing crop models for growers. He obtained his Bachelors in biology with an emphasis in plant health from the Instituto Tecnológico de Los Mochis in Sinaloa, Mexico and recently received his Masters in agronomy from Iowa State University.

Dr. Darren Ficklin is an associate professor in the Department of Geography at Indiana University. He received his bachelor's in geological sciences at Indiana University, obtained his master's in geology at Southern Illinois University, and a Ph.D. in hydrologic Sciences at the University of California Davis. After completing his Ph.D., he stayed in California and did postdoctoral work at Santa Clara University. His current research focuses primarily on the intersection of hydrology and climate.Podcast Transcript:BRAD NEWBOLD 0:00 Hello everybody and welcome to We Measure the World, a podcast produced by scientists for scientists...DARREN FICKLIN 0:07 Yeah. So if you're not familiar with Brood X Cicadas they come out of the ground every 17 years, and these are not, these are not flies. These are several inches in length and a half an inch. So they come out every 17 years, and essentially what happens is when they come out, they leave these gigantic holes in the ground about the size of a dime. And these burrows go about, they can go up to 60 centimeters deep. So they can go relatively deep. So they emerge from the soil. They make their way up the tree, they'll mate on the tree. And then the larvae or nymphs will fall to the ground, dig into the soil, and they stay there for 17 years. So the research question was essentially, how does this how do these burros affect infiltration? BRAD NEWBOLD 0:57 That's a small taste of what we have in store for you today. We Measure the World explores interesting environmental research trends, how scientists are solving research issues, and what tools are helping them better understand measurements across the entire soil plant atmosphere continuum. Today's guest is Darren Ficklin. Darren Ficklin is an associate professor in the Department of Geography at Indiana University. He received his bachelor's in geological sciences there at Indiana University and then went on to get his master's in geology at Southern Illinois University and a PhD in hydrologic Sciences at the University of California Davis. After completing his PhD, he stayed in California and did postdoctoral work at Santa Clara University. His current research focuses primarily on the intersection of hydrology and climate. And today he's here to talk about his many research projects into watershed and soil hydrology, climate change, and bugs. So Darren, thanks so much for being here.DARREN FICKLIN 1:52 Thank you for having me.BRAD NEWBOLD 1:55 All right. So yeah, today, we wanted to talk about a few of your projects and research interests. But first, can you tell us a little bit about your background? And, and then how you became involved in hydrology?DARREN FICKLIN 2:06 Yeah, that's a good question. So I'm, I'm from Indiana, Originally, I'm from about an hour south and I grew up in farmland. And I've always been interested in science. I have no idea why, some of these older, older folks listening may remember, Mr. Wizard, Bill Nye, I watched those all the time. I remember as a young kid, mixing mayonnaise, and ketchup and mustard and making my own chemical, chemical, chemical concentrations there and doing some weird stuff with that. But I've always been interested in science. I don't know really what happened with that. And as I grew older, I got to kind of be in the environment more. And so my dad worked for the USDA NRCS as a soil scientist, specifically what he did is he helped farmers around the region, limit erosion. So that I think that kind of steered me in the direction of the environmental science. And that was, that was essentially I was too young to know what that was. But as I grew up, in high school, I kind of could understand of, you know, what you can do in the environment. I was also really into computers at at the high school, I didn't understand them. In fact, I went to Indiana University, and I was originally a computer science major. And they threw me into a sophomore level course. And I had no idea what I was doing almost immediately. So that was, they threw me in and they were coding on the first day. So I did not understand what computer science was at that age. So I dropped that almost immediately. I talked to the advisor, one of the academic advisors at IU, and they they kind of steered me into this intro introductory geology course. And that was it, that basically, I took off from there, I really, really enjoyed it. And then as I took more and more classes, I took more hydrology classes in the upper levels. And that's really when when I took off as far as I was interested in hydrology, and I think a lot of that stemmed from my, you know, farming background and my dad's work with the USDA.BRAD NEWBOLD 4:15 So, I guess that's kind of fun. This is one of the things that we hear often is that either Yeah, the the folks that are now in their specialties they are quite often didn't start where where they thought or didn't end up where they thought they would end up starting with one thing moving on to another. So going from computer science. So then did with your computer science background, and then geology. So I'm assuming that that GIS then became kind of one of your one of your go twos to connect the two. DARREN FICKLIN 4:46 Yeah, so at undergraduate I started taking a lot of GIS courses as well. That was junior senior level courses, and specifically they were geological applications in GIS, where you would work on I work on my own erosion processes on a hillslope. That type of stuff really, you know, really kind of kind of gelled everything together. For me the computer science aspect. Yeah, I didn't understand that computer science was coding. At that time, I learned very quickly. I mean, now I can code but I didn't didn't understand it when I was entering the undergraduate curriculum.BRAD NEWBOLD 5:20 Right. Well, let's talk, let's dive into some of your current research and or more recent research. A lot of a lot of what you've been working with, especially within the realm of hydrology is hydrology and Hydroclimatology. And and those kinds of they interplay between between climate change and variability and hydrological processes. Can you get, I guess, how did how did you go from from being, you know, working with? Let me back that up. So how did you come to focus more on on this, this, I guess, this interplay, the integration between climate and hydrology?DARREN FICKLIN 6:03 Yeah, so my master's was in groundwater, groundwater hydrology, my PhD was in surface hydrology. So a lot of those are treated separately, they should not be treated separately, but a lot of them are treated separately. So that kind of gives me a little more general idea of the hydrological cycle. And as far as climate change goes, that really started when I was out in California, getting my PhD and it really started. You don't I don't realize this and when you're in the Midwest, but California exists because of its snowmelt snowpack. And I was really interested in how climate change was affecting those variables. So that's kind of what initially got me going on that. And then I took that a little step further and kind of worked on the agricultural aspect of climate change, specifically looking at water quality. I was looking at nitrates pesticide runoff in the Central Valley of California. And then that kind of led me directly in to my postdoctoral work, which, which was mainly on stream temperature, largely due because of the important aquatic species out west salmon, trout, that depend on a particular particular stream temperature to exist.BRAD NEWBOLD 7:13 I'm interested in definitely in the the issues around hydrology within the inner mountain and arid west. I mean, that's that's kind of a big deal now. And it has been for a while, you know, ever since ever since people started living there, you know, water is is a scarce resource, in those more arid environments, and especially like what you were talking about with being dependent on on snow melt on that snowpack, for for that runoff for recharge, for all those other things that we're dealing with, what are some of the questions that you're interested in? And maybe some of the things that you learned? And in researching, particularly with in dealing with with kind of those those more snow dependent regions?DARREN FICKLIN 7:58 Well, would you add climate change to the mix? It's not not pretty, right. So the snowpack barely exists, depending on what what climate change your projection you're looking at and working on. The snowpack barely exist at the end of the century, right. And it's largely due to air temperature, air temperature, precipitation falls that either snow is rain, right snow or rain. And when you have a higher temperature, it's more likely to fall as as rain. And then you put that on an existing snowpack. That wipes it up pretty quickly. So So that's we've done work in the Sierra, the Columbia and the Colorado, and they're all basically telling you the exact same thing, you know, when you increase air temperature, and and even when when precipitation is held steady compared to historical rates, snowpack still goes down. Yeah, so that's, that's generally a conclusion. And that's, that's not a new conclusion. There have been plenty of people looking at that. And still looking at that, and specifically, how these dynamics are going to change and whether these models can capture these dynamics, and then the you add the whole reservoir management aspect of that, which I don't do, but how are you going to manage no water or lack of water when when to release this water? For agricultural irrigation and environmental flows? It's extremely complicated. BRAD NEWBOLD 9:15 Right, and yeah, I mean, personally speaking, I've been interested in in the, the, I guess, the plight of the Great Salt Lake here in in the West, and that, specifically, when you're talking about like, yeah, reservoir management or in dealing with snowpack. T

Steve Blecker PhD is a research soil scientist with the Ag Experiment Station at Colorado State University. He obtained his Bachelor's at Penn State University and graduate degree in pathology at Colorado State University. His research focuses on sustainable agriculture, soil health, and range land restoration. Steve is actively involved in collaborative projects with the farming community and contributes to the advancement of sustainable and resilient agricultural practices.Jim Ippolito PhD is currently a professor in the School of Environment and Natural Resources at Ohio State University. He obtained his Bachelor's in agronomy from the University of Delaware, and his graduate degree in soil chemistry, fertility, and quality from Colorado State University. Jim is an expert in and teaches soil fertility and soil health principles and practices. He is actively involved in research, teaching, and extension activities, working to improve soil health and fertility for the benefit of farmers, land managers, and the environment.Podcast Transcript:BRAD NEWBOLD 0:00 Hello everybody and welcome to We Measure the World, a podcast produced by scientists, for scientists. JIM IPPOLITO 0:07 My gut is telling me that this is where we're going to see the best bang for our buck in terms of return on investment, for improving carbon in our soils, it's going to be in the Western United States, we're going to see drastic improvements. And I'll tell you from some of my experiences with other soil health projects, that if you do things, quote, right, you might see a change in less than five years. In fact, we had a project over on the western slope of Colorado where we saw changes in three years in terms of organic carbon accumulation in the soil surface in three years. BRAD NEWBOLD 0:41 That's a small taste of what we have in store for you today. We Measure the World explores interesting environmental research trends, how scientists are solving research issues, and what tools are helping them better understand measurements across the entire soil plant atmosphere continues. Today's guests are Steve Blecker and Jim Ippolito. Steve Blecher, is a research soil scientist with the Ag Experiment Station at Colorado State University. He obtained his Bachelor's at Penn State University and graduate degrees and pathology at Colorado State University. His research focuses on sustainable agriculture, soil health and range land restoration. Steve is actively involved in collaborative projects with the farming community and contributes to the advancement of sustainable and resilient agricultural practices. Jim Ippolito is currently a professor in the School of Environment and Natural Resources at Ohio State University. He obtained his Bachelor's in agronomy from the University of Delaware, and his graduate degrees in soil chemistry, fertility and quality from Colorado State University. Jim is an expert in and teaches soil fertility and soil health principles and practices. He is actively involved in research, teaching and extension activities, working to improve soil health and fertility for the benefit of farmers, land managers and the environment. And today, they're here to talk about their research into agroecosystem management, soil health, and Ecosystem Sustainability and resiliency. So Steve, and Jim, thanks so much for being here.STEVE BLECKER 2:09 Glad to be here.JIM IPPOLITO 2:09 Yeah, thanks for having us Brad.BRAD NEWBOLD 2:12 Alright. So today, we wanted to talk about a few of your projects and research interest. But first, can you tell us a little bit about your background and how you came to be involved in soil science and your particular specialties?STEVE BLECKER 2:25 Yeah, I just sort of wandered into soils, really, I mean, I didn't really like I didn't really know what I wanted to do at Penn State and I just kept kind of wandering around taking different classes. And the day, I took the I took an intro to soils class, and then it just something just clicked. I was like, wow, this is really cool. I mean, people actually study soils, I mean, wow. So I just took all the soils classes, I could get a hold of, and then my undergrad ran out, and I just wanted to keep going. So turned to grad school. And it's learning about soils ever since.BRAD NEWBOLD 3:03 what got you involved in in kind of the agricultural side and with extension activities?STEVE BLECKER 3:08 Well, that's pretty recent development. For me, I was I was doing more basic research for most of my for a lot of my career anyway. And, and just kind of once, when I came back to Colorado, and in my current position, there was this opportunity to do a lot more kind of applied research, just kind of work with growers in different agroecosystems, it just kind of you know it was exciting to me to be able to, you know, instead of, I used to publish in, not that I don't publish anymore, but in scientific journals, and maybe read by a handful of people, but now it's just it's more I'm more interested in kind of connecting with growers and just letting helping them understand the soils that they're working with. BRAD NEWBOLD 3:56 And Jim, how about you?JIM IPPOLITO 3:58 Well, my, my path into soils is much like Steve's like, when I was an undergrad, I really didn't know what I wanted to do. I was geared towards sciences, like science is in my blood, basically, in my genes. And I knew I didn't want to go into chemistry. My, my family has a long history of being in the chemistry field. So I steered clear of chemistry. I really steered clear of chemistry. And then I stumbled across horticulture class when I was a freshman. I said, Oh, that's interesting. Let me go see if there's any other classes that are offered within the College of Ag at the University of Delaware. And just like Steve, I took Intro to soil science. And I was hooked. I just, it just felt right. And lo and behold, there is a lot of chemistry in soil science. And so I'm a chemist. I consider myself a soil chemist and I love it. I just love what I do. I've been involved with a lot of different sectors though. A lot of ag over my 30 plus year career, in fact, most of it has been an ag but also in, in sites that have been contaminated with heavy metals, or more recently sites that are contaminated with these forever chemical compounds, PFAS's and PFOA's. And, you know, just solving problems, I'm, I'm really an applied soil chemist, I love what I do. And, and I've known Steve, we both known each other's for oh my gosh, since 1990, we went to grad school together at Colorado State University, and our paths have just done this, we've interwoven our paths over the over the years. So, which is why we still work together.BRAD NEWBOLD 5:42 That's good. That's good that you guys still like each other, then after working together so long, more or less. And I do hope that maybe we can come back and talk about those forever chemicals. That was kind of a side, you know, side discussion that I think is really interesting and pertinent to a lot of stuff that's been, you know, popping up recently. I mean, but anyway, we'll come maybe we'll come back to that later. So one of the one of the I guess, themes, or I guess, overarching research interests that seems to be within both of your specialties deals with soil health, or what we have now call soil health I know, in the intro, Jim, we talked about your or I mentioned that your degrees were in soil chemistry, fertility quality, which is kind of what now we would term soil health. I was wondering if you if you guys could just kind of give us a give our audience a basic overview of what we what is considered now soil health, what are the the principles that that go into soil health? You know, how do we, how do we quantify or measure soil health and kind of all those kinds of things?STEVE BLECKER 6:54 Okay, I'll take a crack at it, and then fill in the gaps, Steve, because, you know, when I think about soil health, and when I talk about soil health to a lot of people that maybe are not strongly familiar with soil health, this is how I approach it, I approach it much like discussing human health. And when we go to the doctor, because maybe we don't feel right, and the doctor runs a bunch of tests on us, right, so a doctor may ask you to run on a treadmill, for example, to take a look at maybe physical health, you'll get a blood draw. So blood might be chemical health, and sooner or later down the line, somebody's probably going to start taking some gut microbiome samples from you. And that's a measure of biological health. So when we talk about health, especially with humans, we oftentimes never talk about health directly, but we look at the measurements that we think get are geared towards human health or the like, good human health, if you will, we do the same thing with soils. So in soils, we look at soil physical characteristics, chemical characteristics, and certainly biological characteristics. And we look for the sometimes we call it the sweet spot, at least that's what I call it, where all three of these physical, chemical and biological overlap. And, you know, you can think of three circles overlapping. Many of us have used this analogy before, and looking at where that circle in the center encompasses the, quote, best of physical, chemical and soil, biological health. So that's, that's my approach. And to be honest with you, I've used this approach for oh my gosh, almost my entire career without even knowing it. What do you think, Steve?STEVE BLECKER 8:39 Man, that's a hard act to follow. I like the analogy with the human health. I hadn't thought of that. That's pretty good. But no, I mean, you're right. It's the name has changed, didn't always used to be soil health, but the things we measure, I mean, there's three major biology, chemistry and the physical properties of soil. I mean, you're right. I mean, that's, that's how they interact, to determine

Taylor Bacon is a Ph.D. student of soil and crop science at Colorado State University. She obtained her Bachelor’s in Chemical and Biological Engineering from Princeton University with a focus on energy and the environment and a minor in sustainable energy. As a Ph.D. candidate, she is researching nature-based climate solutions, land-use emissions, and food/energy systems. Podcast Transcript: BRAD NEWBOLD 0:00 Hello everybody and welcome to We Measure the World, a podcast produced by scientists, for scientists.TAYLOR BACON 0:08 I think one of the hardest things we ran into was when we were initially designing this research plan and kind of deciding what data we wanted to collect. Deciding what sensors we wanted to use, where we wanted to install them, is that there is so much heterogeneity and variation within the solar array, even just within a single block of panels across even just a couple feet apart because of these different zones. And it was challenging to balance okay, what can we feasibly measure and what how much data can we feasibly collect, while still capturing enough of this variability to actually be accurate and to have representative data?BRAD NEWBOLD 0:53 That's a small taste of what we have in store for you today. We Measure the World explores interesting environmental research trends, how scientists are solving research issues, and what tools are helping them better understand measurements across the entire soil plant atmosphere continuum. Today's guest is Taylor Bacon, a PhD student in the Department of soil and crop Sciences at Colorado State University. She obtained her bachelor's degree in Chemical and Biological Engineering from Princeton University with a focus on energy and the environment, and a minor in sustainable energy. Now, as a part of her Ph. D program, she's researching nature based climate solutions, land use emissions, and food energy systems. And today, she's here to talk about her research into agriculture ticks, regenerative energy, and land use, and much more. So Taylor, thanks so much for being here.TAYLOR BACON 1:42 Thank you so much for having me.BRAD NEWBOLD 1:44 So today, we wanted to talk with you about your your projects and research interests. So can you tell us a little bit about your background and how you got into to where you are now with environmental sciences and into your your specialty, and you're a PhD researcher?TAYLOR BACON 2:02 Yeah, so as you mentioned in the intro, my background is actually in engineering, I did my undergrad in chemical and biological engineering, focusing on sustainable energy. And my undergrad thesis was looking at bio energy for jet fuel production as kind of a sustainable alternative. But my senior year, I took an environmental policy class, and really just had this moment of being like, Oh, this is what we need to actually make these technical solutions I've been studying and work on happen in the real world, and we can be doing the research. But if there isn't the policy to actually drive that into implementation, that's kind of a missing piece. So I got really interested in environmental policy. And after graduating, got a fellowship at an environmental nonprofit working on climate and clean air and energy policy, and spent a couple of years doing that. And it was really, really valuable experience, I learned a ton and kind of developed an understanding of how all of these drivers work together and kind of what actually has to happen for change towards a like sustainable climate future. But after I was there for like three years, and towards the end, I of my second or third year, I started really missing science and kind of more quantitative work, I was doing a lot of policy analysis and advocacy, but kind of was itching to get back towards the more quantitative side of things, started thinking about what I wanted to do next, and had a couple criteria, I wanted to do something where I could do fieldwork outside and physically be collecting data and kind of be more on the ground. At an actual place collecting actual data after doing a lot of kind of modeling and high level analysis. I wanted to do something that was really solutions oriented. So I wanted to be doing science, but I wanted to be working on science that was kind of directly applicable to these problems we're facing and was really solutions oriented. And then I'd taken a bunch of environmental chemistry classes and undergrad and started kind of looking in that space and found my way to this soil science program that kind of matched all of those criteria. And this project specifically that I'm working on in Agra voltaic is really exciting because it kind of matches my background and sustainable energy and energy policy with this soil ecology biogeochemistry side of things that I'm more recently getting into.BRAD NEWBOLD 4:40 That's awesome. That's super cool. I want to I want to touch on all of that. So but yeah, so can we can we go back you you've mentioned that in your undergrad research and I definitely want to dig into what you're doing. Now. That's going to be the bulk of what we want to talk about today. But it. But you've talked about working with with biofuels and doing research in that aspect. And you said bio jet fuels. That's something that that I am not sure if I'm familiar with, in general with biofuels, but not bio jet fuels. Can you tell us a little bit about about that, and how, how that works with I mean, with jet fuel, it's very, it needs to be, you know, very high quality. And, you know, a lot of more, a lot of other things like that. But can you tell us a little bit about that?TAYLOR BACON 5:31 Yeah, so this was a while ago, so I'm a little a little removed from the weeds. But the idea, or kind of the motivation for this project was that we can electrify a lot of things. And electrification is a really good option for decarbonizing a lot of different sectors of the economy and a lot of different modes of transportation. But large scale electric aircraft are probably pretty far down the line. But in the meantime, we have technological options for creating jet fuel from plant residue from different plant based sources, that when you're growing that feedstock, you're sequestering carbon. So the idea is that then your your bio jet fuel is carbon neutral, because the emissions that are released are balanced out by the carbon that sequestered when the plant is growing. So my thesis was using chemical engineering modeling software to design and model a pathway for converting, I looked specifically at forestry residue as kind of a sample feedstock that has a little bit maybe a little bit better sustainability on the front end, because you're not displacing agriculture, or kind of it's this material that's already there. And there's definitely limitations and collecting it and accessing it. But that's what I use as my feedstock and then designed in model this process. And this modeling software for converting it to a jet fuel, in theory could be used as a drop in jet fuel in existing infrastructure. But didn't economic analysis and was basically like, this is not feasible unless you have really ambitious carbon credits and a lot of policy support, which kind of tied back into the turning of my attention to environmental policy.BRAD NEWBOLD 7:21 Right. So with that, I mean, I would assume that if, if you have a an undergrad at Princeton, who is interested in the stuff that I'm sure there's plenty of other organizations and corporations that are dealing with, you know, biofuel research and those kinds of things. How did that tie into to what the I guess the existing research and kind of research and development was, has been doing in that in that field?TAYLOR BACON 7:46 Yeah, it was actually really great, because there was a company actually based in Oregon, called Red Rock biofuels, that were just starting to try and design and build and implement, I think the the plant was maybe just starting construction when I was working on my thesis for a very similar pathway. So I got to connect with them and chat about their work a little bit. And then there's a bio jet or not a jet fuel, but just a biofuel plant in Iowa. That's one of the only commercially operational ones in the US, I believe, or at least was at the time. So I got funding from Princeton to go to or that plant and kind of see what they were doing. So I definitely, yeah, I did my best to kind of see what was actually happening and kind of where this fit in with what other people were doing. And there were definitely other companies that were kind of starting out on the same path that I was looking at. And we're, we're definitely ahead of what I was doing, because they were actually building a plant rather than just modeling it.BRAD NEWBOLD 8:49 Right. Right. So is that something then art? I mean, I guess, probably not in the commercial space, what are there then, I mean, you know, aircraft jet engines that are running off of biofuel, or like mixed or hybrid fields.TAYLOR BACON 9:04 I think United has been doing a lot on sourcing their jet fuel and incorporating biojet fuel. So it's definitely a pretty small fraction. But there are a lot of people working on kind of setting targets and moving towards having it be more prevalent. And I think there are some airlines that as kind of a way of supporting these pretty young technologies and young plants will agree to buy a certain amount of biofuel, and that can kind of serve as a financing guarantee to actually get these things off the ground.BRAD NEWBOLD 9:39 That's awesome. That's cool. That's fun to see. I mean, it's one of those things where Well, I think a lot of a lot of what's interesting with with what we're going to be talking about today and with your research is that is that there are a lot of things that that we have that are going on right now. That do have that huge potential for for greater impact when it comes

Chris Chambers operates as the Environment Support Manager and has been the Soil Moisture Sensor Product Manager for many years at METER Group. He specializes in ecology and plant physiology and has 15 years of experience helping researchers measure the soil-plant-atmosphere continuum. Leo Rivera operates as a research scientist and Director of Scientific Outreach at METER Group. He earned his undergraduate and master’s degree in soil science at Texas A&M University where his research focused on the impacts of land use and landscape on soil hydraulic properties. He also helped develop an infiltration system for measuring hydraulic conductivity used by the NRCS in Texas. Currently, Leo leads METER’s collaborative research efforts, and focuses on application development in hydrology instrumentation, including the SATURO infiltrometer and the HYPROP. He also works in R&D to explore new instrumentation for water and nutrient movement in the soil.Links to learn more about Leo RiveraAuthor page on Environmental Biophysics Blog Leo Rivera on LinkedInLeo Rivera on ResearchGateLinks to learn more about Chris Chambers Chris Chambers on LinkedInChris Chambers biography on METERPodcast Transcript:BRAD NEWBOLD 0:00 Hello everybody and welcome to We Measure the World, a podcast produced by scientists for scientists.CHRIS CHAMBERS 0:08 So if you have matric potential soil suction, and water content, do you even need to know anything about the soil type anymore?LEO RIVERA 0:17 You know, when it comes to understanding the hydraulic properties of soil? No, those are the things that we need to get to, to know. Now there are other physical properties that we probably need to understand soil type when it comes to like plasticity index and things like that. But for most people, most applications if you know the water content and water potential, and you understand that relationship, that tells you pretty much everything you need to know. CHRIS CHAMBERS 0:43 Any comments on that can go straight to Leo Rivera. LEO RIVERA 0:46 Or Brad just one of us!BRAD NEWBOLD 0:51 That's a small taste of what we have in store for you today. We Measure the World explores interesting environmental research trends, how scientists are solving research issues, and what tools are helping them better understand measurements across the entire soil plant atmosphere continuum. Today's guests are research scientists Leo Rivera and Chris Chambers, both of whom are water content and water potential sensor and application experts here at meter group. Chris chambers operates as the environment Support Manager and has been the soil moisture sensor Product Manager for many years at METER Group. He specializes in ecology and plant physiology, and has 15 years of experience helping researchers measure the soil plant atmosphere continuum. Leo Rivera operates as a research scientist and director of scientific outreach at METER Group. He earned his undergraduate and master's degree in soil science at Texas a&m University. And there his research focused on the impacts of land use and landscape on soil hydraulic properties. He also helped develop an infiltration system for measuring hydraulic conductivity used by the NRCS and Texas. Currently, Leo leads METER's collaborative research efforts and focuses on application development in hydrology instrumentation, including the SATURO Infiltrometer and the HYPROPROP. He also works in r&d to explore new instrumentation for water and nutrient movement in the soil. So Leo and Chris, thank you so much for being here. LEO RIVERA 2:13 Thanks, Brad.CHRIS CHAMBERS 2:14 Thanks, Brad. Happy to be here.BRAD NEWBOLD 2:17 All right. So we probably need to start out by talking about the differences between soil water content and soil water potential. Can, can you just give us a brief definition of both these parameters? What is soil water content? And what is soil water potential?CHRIS CHAMBERS 2:34 Right. And so what we're talking about is ways to describe the state of water in the soil. LEO RIVERA 2:40 Yep. CHRIS CHAMBERS 2:41 And they are both extremely valuable and give you complimentary information. And so the soil water content is the amount of water there, it's how much water is in any given volume of soil. And the water potential is the energy state. So when we talk about these things, people will generally say soil moisture, and they generally mean water content. LEO RIVERA 3:07 Yep. CHRIS CHAMBERS 3:07 We're trying to get a little broader view of soil moisture out there. And it really includes both of these parameters.LEO RIVERA 3:15 Yeah, yeah. And oftentimes, I mean, when people look at water content or water potential, they're typically looking at it in terms of volumetric water content, how much water is there per volume of soil, but geotechnical engineers often often like to look at in terms of gravimetric water content. So it often depends on the field that you're coming from and how you want to look at it. geotechnical engineers also like to call soil water potential soil suction, and they look at it in terms of a positive value. So it's the inverse of water potential, which this takes some time. It takes a little bit to wrap your mind around that sometimes. But depends on the field you're coming from and what you're really trying to understand and how you're using that information.CHRIS CHAMBERS 3:52 Yeah, but in the end, it's the mass and the energy state. LEO RIVERA 3:56 Yep.BRAD NEWBOLD 3:57 All right. So that being said, what types of situations would you only need soil water content? And in the same, you know, the same vein? What type of situations would you only need soil water potential?CHRIS CHAMBERS 4:10 Can we play our favorite game for a bit? BRAD NEWBOLD 4:13 Sure! CHRIS CHAMBERS 4:13 Okay, water content or water potential? Okay, we've done this a couple of times, so you might have seen it before. Bear with us a little bit, okay! Um, so let's start with maybe maybe not as easy as you might think. A setpoint for irrigation control?LEO RIVERA 4:30 Ooh, good question. So, ideally, we're going to control irrigation to hit a target water potential. But we need the water content to know how much water we need to add to hit those target points. CHRIS CHAMBERS 4:45 See, we threw the curve in too early. Yeah, we'll come back to that. Yeah. Let's do a new one. How much? How much tension is going to be on the water column of a plant? LEO RIVERA 4:59 Water potential. CHRIS CHAMBERS 5:00 Water potential all the way. Let's say how, what if what you want to measure if you want to measure the amount? See, I'm giving, I'm giving it away here. It's hard. It's hard to phrase these without giving it away in the question. The amount of water loss.LEO RIVERA 5:17 The amount of... I mean, water content is gonna give us the information there. Right, right. Let me throw one your way. If there's a risk of slope failure?CHRIS CHAMBERS 5:27 Woohoo. So once again, we're back to needing both of those, right?LEO RIVERA 5:34 Yeah, I think, first of all failure water, the amount of water there is helpful, but the biggest factor is the water potential or the soil suction, as I refer to it, because that kind of gives us that intrinsic strength component.CHRIS CHAMBERS 5:50 But sometimes the positive pressure is a factor there too, right?LEO RIVERA 5:52 For sure. How's it? Yeah, yeah. So we're really we're ideally looking at both the negative and positive pore pressures.CHRIS CHAMBERS 5:59 Great. How about freezing potential in, like, say in like a wheat hardiness study?LEO RIVERA 6:10 Ooo oh a curveball in there. Yeah. That's a good question. Freezing potential. I mean, I think water potential is probably going to govern that more. Right. But also, we could use I mean, if it actually frozen, we can use temperature to infer the water potential.CHRIS CHAMBERS 6:25 Yeah and that will kind of give you the same information. Right? When you when you hit the freezing point, they're both going to just look like really dry soils.LEO RIVERA 6:32 Yeah. Yeah. And then from there, you can use temperature to kind of infer guess what, what's happening there.?CHRIS CHAMBERS 6:38 So as long as we play this game, you think we'd be better at it by now.BRAD NEWBOLD 6:43 All right, so you have given us a couple of instances here examples of when a water content and water potential work well together. So are there any other or not are there? But can you give us some other examples or situations when it's appropriate to measure both of those parameters at the same time,CHRIS CHAMBERS 7:01 so people are really used to using water content? Because it it's easy to understand, right? Basically, at the end of the day, you get a percent. And that's really easy for people to wrap their head around. Yeah, you're looking at a volume of soil, that's 25%. water content, volumetric water content, then right about the fraction of quarter of that soil is made up of water. Unfortunately, it's a lot harder to interpret than many people realize. Because 25% water content in a sand is more water than any plant needs. And in a clay, it's probably well beyond the permanent wilting point. So you can't really just use water content. In some situations, you either need the matric potential as well. Or you need to know some more information like the soil type.LEO RIVERA 7:55 Yeah. And I think I'd even argue that in most situations where people are just using water content, they're doing it based on historical knowledge of what that means for that soil. And really, it's because they've spent enough time knowing what that means in terms of water potential without knowing that they're actually trying to understand that they're like, my plants are happy, my plants are sad. These are my set points for water content. CHRIS CHAMBERS 8:19 Especially in seasonal areas, we've got a couple of years of data, you know, where i