Podcast: Play in new window | Download
Subscribe on iTunes | Android | Stitcher | SoundCloud | Spotify | RSS feed
For those of you who are newer to the medium, a podcast is like a pre-recorded radio show. In the same way that you turn on a talk radio show, you have to turn on a podcast. The major difference is that while our cars are equipped to find radio frequencies, they are not built to accommodate direct access to podcasts. On your smartphone or computer with internet access (since the files tend to be on the larger side), you can discover podcast shows of any kind, in any field, on any topic.
Listed above are some of the most used podcast hosts. iTunes and the iTunes Podcast app are preinstalled on your iPhone and are the simplest tools to use. You simply search for “WSU Wheat Beat Podcast” in the search bar, hit “subscribe” and the download arrow, and listen whenever it’s convenient for you.
If you use an Android or use another type of smartphone, you will need to find a different podcasting app because those devices don’t come with a preinstalled app like Apple. If you don’t know which podcast app you’d like, simply hit the “Android” link above and it will show you to several Android podcast apps for you to choose from.
After you download an episode, you can listen without using data any time of day. Our goal is to post a new podcast every other Monday. Your podcast app should automatically load our new episodes and download them for you (on WiFi), hands-free if you choose that in the app settings.
If you have further questions about what a podcast is, which app is best for you or need more assistance with getting started with podcasts, don’t hesitate to contact us.
Episode transcription:
[MUSIC]
Drew Lyon: Hello, welcome to the WSU Wheat Beat podcast. I’m your host, Drew Lyon, and I want to thank you for joining me as we explore the world of small grains production and research at Washington State University. In each episode, I speak with researchers from WSU and the USDA-ARS to provide you with insights into the latest research on wheat and barley production.
If you enjoy the WSU Wheat Beat podcast, do us a favor and subscribe on iTunes or your favorite podcast app and leave us a review so others can find the show too.
[MUSIC]
My guest today is Diana Salguero. Diana is pursuing a Ph.D. in soil science at Washington State University working with Dr. Haly Neely. Her research focuses on understanding how soil compaction and different soil properties impact crop performance, something many farmers deal with firsthand in the field. Before this, Diana earned her master’s degree at Purdue University, where she studied how corn yields respond to sulfur fertilization across Indiana. She’s passionate about helping farmers optimize soil health and crop performance through practical research.
Hello, Diana.
Diana Salguero: Hello, Drew.
Drew Lyon: Welcome to the Wheat Beat podcast. So, is compaction really something growers need to be concerned about in this semi-arid dryland cropping system region?
Diana Salguero: Yes, it is indeed, and I will say farmers are very knowledgeable of this problem. Just it has been hard to measure and really know the magnitude of this problem. And the reason it’s an issue or a concern around here is because compaction really affects root growth as well as water infiltration, which at the end of the day, it’s going to affect plant water availability for the rest of the season.
Drew Lyon: Okay. And in this particular part of the world, which I learned after getting here, stored soil water is pretty important to how crops finish because we really don’t get much rain in June, July, and August when some of these crops are trying to finish, so having a profile that’s got as much water in it as possible and a root system that can find it is pretty critical, isn’t it?
Diana Salguero: Absolutely. Especially with everything you have around where most of it is rain fed.
Drew Lyon: Right. So, you mentioned it’s hard to measure. How do you measure compaction?
Diana Salguero: Well, the direct measurement of compaction is going to be bulk density. But measuring bulk density at field scale requires just so many hours that it’s not attainable. And direct measurements of compaction, we have explored many–some of those can be measurements from soil properties or from the plants–and these measurements are highly correlated with bulk density, so that those we call indirect measurements.
Drew Lyon: So, for those who might not understand what bulk density is, how do you measure bulk density? What is it?
Diana Salguero: Well, you take known volume–let’s say a cylinder, that’s a way to determine what density–you take a soil sample, and then you dry that sample and determine how much soil you have there divided by the volume. [That] is going to give you what we call bulk density. So, it tells you how much soil you have there by your overall volume. In general, this soil is composed by soil but also by air. And that space between your soil particles is what is going to host air and water.
Drew Lyon: Okay. And then in a healthy soil, you want a nice balance of pore space and soil particles, right?
Diana Salguero: Absolutely. Yeah.
Drew Lyon: Yeah. So, I remember back in Nebraska when I was working there, I tried to do some soil compaction things and had a, like, metal rod you tried pushing in–and of course, the guy next to me who weighed 250 pounds could put that rod in a lot easier than I could weighing 165 pounds. And then there were some other little tools you push and it would kind of measure resistance, but it really was affected by how much moisture was in the soil.
So, it’s not an easy thing to measure from what I understand. But you do have these indirect measures that you’ve used and probably allows you to do it over a larger region than you could if you had to walk around with a stick or a probe and probe every piece of ground.
Diana Salguero: Yeah. That was actually one of my main projects or the main thing I have been doing during my Ph.D., and it’s to put together a protocol that will allow you to measure or evaluate compaction at field scale without having to spend so many hours or even days surveying a field for compaction.
So, what we did was to use–well, first we determined that we need to know or evaluate compaction in the soil profile by depth and also across the field. So, for the first part, we use penetration resistance and soil moisture by depth to estimate bulk density in the soil profile to find where do you have a compacted layer.
And then for across the field, we evaluated multiple environmental variables from digital elevation models and from satellite images to find which ones can we use to estimate bulk density. So, that is how we put a protocol to evaluate compaction overall at field scale in a much shorter period of time than just using bulk density.
Drew Lyon: Okay. And, how does that protocol work for you? Are you feeling pretty comfortable with it or are there still some things you need to figure out?
Diana Salguero: Yeah, this stage we are now–we are confident on the protocol. We are able to distinguish where do you have a compacted layer in the soil profile and also to distinguish areas within the landscape that are more or less compacted.
We do have to improve the accuracy of those predictions. We use 12 to 18 points for an average field. I’m thinking we need to maybe double that number or include 50% more of the points we use to improve the accuracy, but I’m feeling pretty confident that that’s a way we could use to evaluate compaction.
Drew Lyon: Okay. And in your studies, is there a common place where you tend to find compaction at a certain depth or certain landscape position? Any consistencies in what you’ve done so far?
Diana Salguero: Yeah, we find lower areas in the landscape that tend to be more compacted because early in the spring or after a rainfall those areas are going to stay wetter for longer. And if you drive over, they are going to get more easily compacted than other areas higher in the field.
Drew Lyon: Okay. So, is there a particular depth it tends to be at, like is it a depth at which there’s some kind of practice farmers could do to alleviate that compaction, like if it’s in the top six inches maybe a certain kind of tillage will impact it? Or are you finding it deeper than that? Or does it depend on the site?
Diana Salguero: Well, I will say my concern is more towards subsoil compaction because that is harder to remediate, and if you have compaction at the top, you can treat that with just having plants breaking through that compaction. Or even if you want to till, even that, although that is a short-term solution.
Subsoil compaction, we don’t really have an effective way that you can treat that especially in the short term, so we really want to avoid that. And from what I have seen in the locations I have in Davenport and Fairfield, we are finding compaction below 30 centimeters. What is that?
Drew Lyon: About 12 inches. About a foot.
Diana Salguero: Yes, about a foot. And that’s really worrying because of what I just said, we don’t have a good way to treat that yet.
Drew Lyon: Okay. Very interesting. Yeah, that takes a lot of horsepower to drag something through there or get a root that strong enough to penetrate that. Any idea–and that is part of this driving over wet soils, you think, is compacting it that deep?
Diana Salguero: Absolutely. In crop systems, which are my target, the main reason or the main driver of compaction is dependent on what we do with traffic equipment. And over time, equipment has become heavier, which has helped get things done faster, but it has also increased the risk of subsoil compaction occurring.
Drew Lyon: Okay. So, you’ve developed this protocol [and] you think maybe it needs a little fine tuning. What’s the hope that at some point crop consultants or growers can use this protocol to estimate compaction in their fields? Or how do you see what you’ve done being rolled out and used by growers in the region?
Diana Salguero: Yeah. I think if we have farmers that are concerned about their field and they are curious about if they have a problem with compaction, where in the field. This is something that we can implement to find those areas because the issue with compaction is that is it can be masked across the field.
It can hide if you just look at yield overall, so that will be one way. Something else I see for this project down the line is to be able to make it applicable across a larger area. So, if we have a way to estimate bulk density or evaluate compaction for a larger field without having to do much sampling, that will be great.
Drew Lyon: Okay. So, working in soils, doing things that you can’t see from the surface, it’s tough work. So, congratulations on having the fortitude to deal with that and it sounds like you’ve made good progress. Can listeners go somewhere to see more about the work you and Dr. Haly [Neely] are doing in soil compaction?
Diana Salguero: Absolutely. I would love to answer any questions or discuss some more about my research, and they can reach me out or reach Haly out to my email or hers. Maybe you can add our information at the end of the podcast.
Drew Lyon: Yeah, we’ll get that added to show notes. Is there a website they can go visit to see anything?
Diana Salguero: Not yet.
Drew Lyon: Not yet. Okay. Something in the future. Okay. We’ll get those–that information in our show notes.
Diana, thank you for sharing your research. It sounds promising. And, yeah, I think compaction gets missed by a lot of people, but it’s really critical, I would say, particularly in a dryland situation where you’re dependent on rainfall and stored water to make your crop finish and yield well.
Diana Salguero: Yeah. Absolutely.
Diana Salguero: All right. Thank you, Diana.
Diana Salguero: Thank you. It was my delight.
[MUSIC]
Thanks for joining us and listening to the WSU Wheat Beat podcast. If you like what you hear don’t forget to subscribe and leave a review on iTunes or your favorite podcast app. If you have questions or topics you’d like to hear on future episodes, please email me at drew.lyon — that’s lyon@wsu.edu — (drew.lyon@wsu.edu). You can find us online at smallgrains.wsu.edu and on Facebook and Twitter [X] @WSUSmallGrains. The WSU Wheat Beat podcast is a production of CAHNRS Communications and the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.
I’m Drew Lyon, we’ll see you next time.
[MUSIC]
The views, thoughts, and opinions expressed by guests of this podcast are their own and does not imply Washington State University’s endorsement.