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Mike Howell (00:08):
Hello everyone, and welcome to our first edition of The Dirt. I’m your host, Mike Howell, senior Agronomist with Nutrien. The Dirt Podcast is designed to be an educational outreach to deliver timely agronomic and soil fertility research, news, and information that listeners can use to become better educated on these topics. We will also have guest speakers join me to bring their expertise on the topic of the day. In addition, we will have some regular guests that will join us to provide information on topics like global market trends and weather trends that will affect crop production. The Dirt is being brought to you by eKonomics farming’s. Go-to Information Resource on the eKonomics website, www.Nutrien-eKonomics.com you’ll find concise summaries of the latest crop nutrition research tips and tools for more productive soils, industry news, commodity futures, prices, rainfall data, as well as our Nutrien ROI calculator and nationwide Nutrien balance analysis, and much, much more.
(01:18)
Before we get started with this first episode, I want to take a few seconds and introduce myself. I’m Mike Howell, senior Agronomist with re. I’ve been with Nutrien for about 10 years now and provide technical support primarily to the eastern and southern regions of the United States. I’m based in South Mississippi where I’ve lived for most of my life. Agriculture has been a way of life for me as long as I can remember. I grew up on a university research farm here in Mississippi, and at a young age I became interested in agriculture. I was a member of 4H with my main project being agriculture. As part of this project, I learned about cattle, sheep, soils, crop production, and numerous other topics related to agriculture. Through this, I had the opportunity to explore many areas of agriculture across the United States. After high school, I attended Mississippi State University where I earned a BS degree in soil science and a master’s degree in entomology.
(02:17)
After graduation, I worked as an agronomic research manager on a research farm in the Mississippi Delta, and later served as an extension agent with the Mississippi State University Extension Service. In July of 2012, I joined the Agrium team, which later merged to form Nutrien.
(02:35)
Again, welcome to our podcast. We are recording this episode, March the 1st, and things are starting to get busy in the fields. Here in the south many growers are getting ready to start corn planting just any day now, and growers further north aren’t too far behind. I thought a good way to begin this podcast series, given that planting is just around the corner, would be to start off talking about taking soil samples. Today we will begin our discussion talking about the importance of soil sampling, why growers should take soil samples, and how to properly take a good soil sample. Then in our next episode, we will explore a soil test report and talk about different aspects that growers need to understand to make better decisions about fertility management. Today I’m joined on The Dirt by Dr. Oscar Ruiz Agronomist with Waypoint Analytical Services. Dr. Ruiz, thanks for joining us and welcome to The Dirt.
Dr. Oscar Ruiz (03:29):
Hey, Mike. How you doing? Thank you for having me.
Mike Howell (03:31):
I’m doing great. If you would tell our listeners a little bit about yourself and what you do for Waypoint Analytical.
Dr. Oscar Ruiz (03:37):
I’m originally from California. I got my background in agronomy out west. I did cotton scouting when I was a kid. I worked in my college farm. I have a background in berries, Central California. I did some vegetable scouting out in Florida while I was doing grad studies. I worked on golf courses. I have background in nematode, plant disease diagnostics, turf diagnostics, and I’ve been here at Waypoint since it was A&L Labs since 2008. So yeah, so I’ve been here since 2008.
Mike Howell (04:17):
Okay. That’s quite a diverse background. I know that Central California area is a great place to visit. A lot of people think about California and I was this way till I went out there. You think about the big cities, and that’s totally not what the central part of California is all about. A lot different,
Dr. Oscar Ruiz (04:33):
Completely different. You’re in a different state. Put it that way.
Mike Howell (04:37):
That’s right. Dr. Ruiz, I know today we’re talking about soil sampling and that’s a big part of what you do at Waypoint, but tell us a little bit more about Waypoint Analytic and what all services y’all provide to growers there.
Dr. Oscar Ruiz (04:49):
A lot of folks don’t know this, but apart from being a full service agricultural lab, we’re also a full service environmental lab. We’re located in several states all over the country. As an ag lab, we do a lot of plant tissue, Nutrien testing, water analysis, pesticide residue. We’ll do nematode analysis, plant pathology, diagnostics. We do a lot of manure compost testing. Okay. Manufactured soils is a big thing.
Mike Howell (05:18):
Dr. Ruiz, I’ve invited you on today and asked you to help talk us through soil sampling. So if you would, let’s get into the dirt, and first off, just tell us what a soil sample is.
Dr. Oscar Ruiz (05:29):
Real basic. It’s a tool. It’s an information gathering tool, and it just helps you determine how to create a fertility programme, and it’s just a decision aiding tool.
Mike Howell (05:42):
So why is it so important to take a soil sample? What are we trying to get out of a soil sample?
Dr. Oscar Ruiz (05:47):
Well, the first thing is, it’s important to clarify, Mike, that there’s a couple different types of soil samples. You have the soil sample that helps you diagnose in-season problems or issues. It should be taken right at the time when you see the problem. And then there’s the other more conventional soil sample where you are using it to help monitor your soil, test nutrient levels over years and help you create your fertility management plan.
Mike Howell (06:18):
So you mentioned if we’re having problems, we need to take those when we first see the problems though, what about our conventional soil sampling programs? When’s the best time of year to take those samples?
Dr. Oscar Ruiz (06:29):
Well, conventional soil samples, I’m assuming those are like what you would do right prior to establishing your fertility program. Most people do them at the end of the season or at the beginning of the season. After harvest or prior to pre-plant.
Mike Howell (06:49):
Okay. Now, I assume you can get good, accurate information either time you take that sample, but one thing I’ve always heard is you need to make sure you take those samples the same time of year every year, because your results can be a little different depending on the time of the year.
Dr. Oscar Ruiz (07:04):
Yeah, that’s right, Mike. It’s important for your samples to be consistent. Same time of year, if you’re taking them in October, stick to October. If you’re taking them in February or January, take them that time of year as well because they will fluctuate. A lot of stuff’s happening throughout the year. The plant’s growing. It’s taking up bases, the grower’s putting on fertilizer. You can see a dip by a couple points, several points in the middle of the season. You could see a difference in PHs or nutrients from the fall to the spring. So that’s important to take into consideration, make sure you’re consistent, and that’s not just in time. It’s also in time and space. You take samples, making sure that you’re consistent as far as depth, because some nutrients can stratify and location. If you can pretty much stay close to where you had originally taken those samples, you could best monitor those positions. Now, there’s another school of thought where they might want to move around, but again, you need to take that into consideration.
Mike Howell (08:09):
So how often do we need to sample an individual field?
Dr. Oscar Ruiz (08:12):
Well, it really depends on a couple things, right? General rule of thumb is the higher the yields, the higher the removal rates, the more intensively managed, the more frequent the sampling. Also, the lower the nutrients holding capacity, the propensity for you to lose nutrients from that soil will also increase the suggested frequency of that soil sampling, your textures involved, your CECs involved, your yields are involved.
Mike Howell (08:44):
Okay. So do you recommend for a cotton or a corn crop, we need to take those samples every year? I know a lot of growers have a mindset we may want to wait two or three years. What’s your recommendations on that?
Dr. Oscar Ruiz (08:56):
Again, I think it depends. All right. You have to look at the whole thing. You have to look at your soil type, your yields. Personally, if I was a grower and I wanted to establish a trend, probably for the first two years that I start sampling that field first two or three years, I’d sample them every year and then see how those nutrients may change or may not, and then go to a 1, 2, 3, or four year. I’d stick to the three, then go to that type of frequency. Just based on observed information, not just pick a year.
Mike Howell (09:34):
Right. That’s where we were hoping to get to with that. That’s the information, we’ve got to build that database and know what we’re doing and not just stretch it out.
Dr. Oscar Ruiz (09:42):
Yes.
Mike Howell (09:43):
Perfect. So Dr. Ruiz, if you will take me through the process of actually collecting a soil sample. What tools do I need? Where do I need to go in the field? How deep do we sample? Things like that.
Dr. Oscar Ruiz (09:55):
If I was a grower or consultant, first thing is I’d have all my tools in place. I’d either have probe, an adequately tipped probe also as well, thinner probe tips for heavier soils, sharp shooter, spade, some folks in dryer soil might require an auger drill tip with the bucket, catching that soil in a bucket, definitely a bucket and a way to get out there. And also a well-defined area to sample. You may have an area that is being sampled as a whole grade sample or zone sample, well-defined spots in the field where you’re going to take that sample. And then once you’re out there and taking your sole sample, you’ll need to take at least a 10 to 12 subsamples per sole sample. And the sampling depth typically averages between four to eight inches, with six being the average depth.
Mike Howell (10:53):
Okay. You mentioned a bucket and years ago I was working with the extension service in Mississippi, and I don’t know if this was a true story or just one of the extension service tails that went around, but-
Dr. Oscar Ruiz (11:07):
I know where you headed this. I think I left out the zinc bucket. Don’t use a zinc bucket or a metal bucket or a rusty bucket. Stick with a clean plastic bucket.
Mike Howell (11:15):
There you go. You’ve heard that story too.
Dr. Oscar Ruiz (11:17):
Yes. Yes. And I do tell it that way. Yeah.
Mike Howell (11:20):
Okay. So we’ve got our samples pulled and we mix them up in the bucket and send them off to our appropriate lab and wait on our soil test to come back. Let’s look at a little bit of certain situation. In the Mississippi delta we’ll have fields that are really sandy on one end, as you walk through the field, you turn into clay, and the farther you walk, the taller you get that clay will actually stick to your boots that much. So what do we do in a situation like this? What’s the best way to handle that?
Dr. Oscar Ruiz (11:46):
Yeah, you’re definitely going to have to take more than one sample. You know you’re going to end up with a different management on both sides of that field. Your nutrients are going to be held the same. You’re probably not going to see the same problems, yield, water holding capacity on both sides. So at least if you’re doing composite samples, you’d have to at least split the field in two. I think I also forgot to mention in your previous question, is addressing the number of subsamples or cores per sample. It’s important to take at least 10 to 12 subsamples per soil sample and mix those up thoroughly, because if you take too few cores or subsamples per soil sample, then you may allow outlier effects. Again, even within those core samples or subsamples you may have variation in soil test levels. So the more samples you take, the less it becomes an effect on your soil test result, and you could get a more accurate picture of that nutrient doubles in that area.
Mike Howell (12:52):
Right, right. More subsamples is always better. It really doesn’t matter what we’re evaluating. I’m a big proponent of more data is always better.
Dr. Oscar Ruiz (13:01):
Yes, that’s right.
Mike Howell (13:02):
So I know a lot of growers these days are looking at variable rate technology. They’ll do some grid sampling or zone sampling. Talk to us a little bit about taking zone samples or grid samples and why growers may be interested in doing that.
Dr. Oscar Ruiz (13:16):
So zone sampling is typically based on information that you already have regarding nutrient distribution in the field, yield across the field, textures, just established knowledge, and it’s a way for a grower to probably reduce the number of soil samples taken. Now, these soil samples may not occur at the same density as a graded field, where the field can allow you to see all the variation in the field. In some fields, probably to greater degree, to greater extent than the zone sample field. It’s the grower and the consultant’s going to have to be the best judge of that. But a grid sample will cover all your bases as far as seeing all the variation, and it’ll take that all into account. So if I had to begin a precision variable rate application program, I would start right off the bat with a grid, and grid samples are typically anywhere from two, two and a half to five acre grids. That’s average density of samples.
Mike Howell (14:19):
Dr. Ruiz, I think that’s all the questions I had today. Is there anything else that you think is important that we need to address before we close this episode?
Dr. Oscar Ruiz (14:27):
I think we’ve covered it.
Mike Howell (14:29):
Okay. Dr. Ruiz, I want to thank you for joining us today. You’ve given us a lot of timely information that our listeners will be able to use to help them take better soil samples, which should give them better results on their reports. You talked about the need for soil sampling, how to properly take a soil sample, and the importance of being consistent in taking these samples. Finally, I just want to add that soil sampling is a vital step that all growers should be taking as part of their soil fertility plan. Without a good soil sample, it is impossible to know what Nutriens are in your soil or what needs to be added to achieve optimum yields. Soil sampling is also a great way for farmers to be more productive, while at the same time managing what they are applying to their fields, making them more profitable and better stewards of the land and our natural resources.
(15:22)
Before we close, I want to let everybody know about a couple of upcoming events. On Tuesday, March 22nd at 10:00 AM Central Standard Time, Dr. Kristy Preston will be presenting a webinar entitled Science-Based Nutrient Management in Times of High Fertilizer Prices. In this webinar, Kristy will discuss the science behind nutrient management strategies and what is recommended to increase return on investment. She’ll be diving into questions like Agronomically, does it make sense to switch crops being grown in 2022, and how do you use science to decide how much fertilizer to apply this year?
(16:01)
To register for this event, go to www.Nutrien-eKonomics.com. And I also want to remind everyone that March 22nd is also National Ag Day. It’s a day to recognize and celebrate the abundance provided by agriculture. Every year producers, agriculture associations, corporations, universities, government agencies, and countless others across America, join together to recognize the contributions of agriculture. The National Ag Day program encourages every America to understand how food and fiber products are produced, to value the essential role of agriculture in maintaining a strong economy, and to appreciate the role agriculture plays in providing safe, abundant, and affordable products. For more information on National Ag Day, you can visit their website at www.nationalagday.org.
(17:02)
I want to thank our listeners for joining in today and invite you to join us next time on The Dirt when we are joined by Dr. Nathan Slayton with the University of Arkansas to talk about how to interpret a soil test report. For more information on soil sampling, you can visit our website at www.Nutrien-eKonomics.com. We also welcome any feedback about this podcast or suggestions for future episodes. Thanks again for listening.
