Landon Baumgartner 0:00
Okay, and now to talk a little bit more about nutrient management planning and how its relationship with soil health manifests itself, we have Chris Bandura here, Conservation Cropping Systems Outreach Specialist with the UW Madison Division of Extension, and Jamie Patton, the State Agronomist for the Wisconsin USDA NRCS here to talk a little bit about this topic. So the first thing I wanted to kind of throw at you guys was soil fertility and soil health. They’re not exactly synonymous. So how do they either positively or negatively impact each other? Like, are they always synergistic? Is there sometimes antagonism that exists with the way that we measure soil health versus soil fertility? Because I think a lot of people end up either mistaking the two as the same thing, or they know a lot about one and not about the other.

Chris Bandura 0:55
Yeah, it’s a really good question. Landon, and thanks for that. Yeah, so oftentimes, when we talk about our soil health journey, a lot of a lot of what we mean by that is soil function. And a component of soil health and functioning soils is soil fertility, which primarily relates to the chemical aspect of soils that we think about, right? So things like pH and soil test P and K, nitrogen cycling and the like. So certainly, soil fertility is a component of soil health. They are definitely not the same thing, right? Because soil health, we’re looking at more than just those chemical aspects. We’re looking at biological activity, the abundance of different biological communities in that soil. And we’re also looking at physical attributes and characteristics of the soils too. So in general, when we talk about building a healthy soil system or a highly functioning soil system, soil fertility is a core piece of that. When we start talking with people about, you know, where do we start? Oftentimes, we’ll say, look, let’s not forget about the basics, right? The fundamentals of make sure our pH is in a good range, right, between six and seven for most of our crops. And let’s make sure soil test p and k are somewhere near the optimum range to really make sure we have enough nutrients there for crops to to grow successfully. And then we can start to look at maybe some of the more challenging management things that we do when we talk about building soil health systems.

Landon Baumgartner 2:35
And across those systems, you know, do we generally see sort of the same, you know, features of soil health across climate zones, cropping systems, I guess I’m kind of looking at at you, specifically Jamie, who’s been around a lot of the country and seen many different systems on many different soils. You know, do you do you see the soil health manifesting itself sort of in the same ways we know soil fertility is, you know, more or less a chemical practice for soil health, you know, is that kind of a universal you know. Do the functions of soil, either good or bad, manifest themselves in ways equally across these systems?

Unknown Speaker 3:16
That’s a great question Landon. So when we think about it, when I think of soil health. No matter what the system is, I’m going to be looking at the same key properties, right? So I’m, I’m more of a physical property kind of person, so I really like to look at aggregate stability. I like to look at bulk density, thinking about that compaction. I like to look at some microbial activity. So while I’m looking at the same factors across all different kinds of soils, different kinds of landscapes, climates and cropping systems, I’m going to have however, different expectations for the range of values that I might expect. Right? So if, for example, if I’m working with a sandier soil, I’m going to expect, potentially, a lower aggregate stability that would still be considered, quote, unquote good as compared to a finer textured soil. The reason for that is simply because of how those soil particles interact with each other. It’s easier to form an aggregate when I have more clay in the system versus when I have more sand in the system. So even though I’m looking at the same property, I’m going to have different expectations the same thing when I’m looking at organic matter, right? We know organic matter is contents are influenced by soil texture. They’re influenced by climate, they’re influenced by a cropping system, and what I consider good or needs improvement in those systems is going to be based upon that context. So while the soil properties are the same, my expectations for those soil properties differ. Does that make sense?

Landon Baumgartner 4:44
Yeah, I think my favorite word when it comes to soils, recently, in the past couple years, has been context, like amongst anything else. So how do we test our progress on our soil fertility or our soil health journeys like, how do we track, you know, from one year to the next? Is, you know, where we’re at between these, these two metrics, and I guess I want to lean toward around on the soil health part of this, because we know about soil fertility and soil testing. Yeah.

Chris Bandura 5:09
So really good question. And there’s a number of ways you can evaluate soil health or soil function, right from year to year. And at the most basic level, instruments that are your eyeballs can be extremely helpful. So we can see how that field is handling equipment. We can see how it’s handling moisture, excessive rainfall. We can see how that crop is handling different stressors and things like that. So our eyes, our feet, our tires going across the field, a shovel right some very basic tools we can use to evaluate what’s happening in that field from year to year as we implement changes in our management over time, and look at how those things change. There’s also a number of laboratory tests so similar to what we’re more familiar with, or what we talk about a lot more in the context of nutrient management or so soil tests, P and K and pH, we have different tests that look at some different chemical indicators of soil health and function, as well as biological and physical. Here at UW, what we’re currently working on is a project kind of going back to that word you just used land in that context. So there’s a number of different soil health tests or indicators out there available for farmers and agronomists to use to help evaluate and to help make decisions and so on and so forth. One of the hard things here at the University, or in the state of Wisconsin, is we don’t necessarily have a lot of research to understand what is a good or optimal or target soil health test value. And so also, again, back to context, simply just understanding, if I go and do a Potentially Mineralizable Carbon test. That’s one that we talk about quite a bit for evaluating soil health. If we get a result of 50 parts per million on that test, what does that mean? What does that mean to the neighbor across the road from my farm? What does that mean to someone on a similar soil type across the state, for me and so on. So we’re working on pooling data. It’s a pretty good data set from across the state, across different soils and temperature, precipitation regimes and certainly different management practices out there to try to get some some understanding of what you might call normal right? What do we normally observe when it comes to some of these different indicators and and so the important aspect that we want to make sure we focus on, regardless of which tests or indicators we use, is number one, to understand the importance of collecting a good baseline so getting representation across that field or farm, taking baseline soil health samples, understanding kind of the nuance of some of these different tests. You know, are they highly variable, just given the nature of the test? But then, so getting that baseline, implementing some management change, and then tracking that throughout time. And it’s important, you know, when we talk about sampling time, so time of year is a big impact on many of these whole health tests that are out there. So if we’re sampling in June in our baseline year, we might consider sampling in June in future years when we’re trying to evaluate how things may or may not be changing.

Landon Baumgartner 8:35
Yeah, you don’t want to have a test, you know, provided to a farmer and then have them say, okay, yeah. What do I do with this? Having answers, and, you know, actionable items is definitely a key thing for the last for the last couple minutes, I want to throw this one at you, Jamie. I think you’ll have some interesting thoughts on this one. Can you have one without the other? And by that, I mean, can you have good like soil function, soil health and poor soil fertility, or can you have good soil fertility and poor soil health? If so, what are we missing out by not having both?

Unknown Speaker 9:10
That is an awesome question. Landon, so when we think about it, I would argue that yes, we can have good fertility and poor soil health, and we have can have good soil health and poor soil fertility, because when we think about those definitions, right? So when we think about a natural system, for example, as I’m sitting here talking today, I’m looking out at this beautiful forest, right? That beautiful forest has great soil health. If I actually did a soil fertility measurement out there, it’s actually going to come back fairly low, although, but that system is very much functional and is very much healthy. So when we think about these, they’re they’re not one in the same they do play into each other, and has to come back to our expectations, right? So where could I have high soil fertility and low soil health? That’s actually fairly common, right? So because soil fertility measurements are a measurement of the concentration of nutrient out there. If I am applying a large amount of nutrient out there, and I’m building that up over time, and it’s very simple to to bring those fertility levels up, but maybe I’m using practices that are decreasing organic matter over time, that are decreasing aggregate stability, that are increasing compaction, that are decreasing microbial activity, so on or so forth, right? And so I can have high fertility and low soil function. I can also have high soil function and low soil fertility, right in that forest example that I’m that I just provided, right? So it has to do with that balance. And when we think about these, that’s the that’s the challenge with using these very subjective words, such as good and poor, right? It really depends upon and we’re coming back to this word again, context, right? What do I expect that system to do, and how do I expect that system to function over time? And that will start to derive what I consider to be good or bad in either one of those individual measurements. So yeah, it’s kind of it’s kind of hard to think about, because we oftentimes think fertility and soil health go hand in hand, and they do. But that may not be the case, depending upon the system I’m working with. Chris, what do you think about that?

Chris Bandura 11:19
Yeah, you stole the words out of my mouth, Jamie, that’s exactly where I would have went with that question as well. So really good recap, and I think again. You know, we know the short term, the short term things that we try to manage, like fertility, like you mentioned, they’re easier to manage. We have sound recommendation systems that generally do a pretty good job at taking a soil test. P for example, from something that’s very low to optimum addressing that short term to produce a decent crop this year, right in terms of nutrient availability, and that that longer term game of, you know, enhancing inherent soil nutrient cycling, nutrient retention, and ultimately making nutrients available to crops and water available to crops and dealing with stressors. That’s that long term game. So in that sense, they’re also right, not synonymous. So the timescale for how we address problems with fertility versus soil health are also quite different.

Landon Baumgartner 12:27
The measurements are different, so the tools to address them are different, absolutely. Well, wonderful. Thank you so much Jamie and Chris for providing that insight for soil health and nutrient management. Today, we’ll talk with you again soon, likely at another field notes podcast, thanks.

Will Fulwider 12:51
Thanks for listening. This has been field notes from UW Madison extension. My name is Will Fulwider regional crops, educator for Dane and Dodge counties. A big thank you to Joe Ryan for creating our theme music and to Abby Wilkimacky for our logo. If you have any questions about anything you’ve heard today or about your farming practices in general, reach out to the extension agriculture educators serving your region.