Developing Weed Control Methods for Organic No-Till Systems | Dr. Erin Silva

Hi, friends. This is John, and this is the Regenerative Agriculture podcast where we talk about agronomic science and cultural management practices that have the capacity to regenerate soil health and plant health and livestock health and ultimately, of course, public health. And in order for us to sustain that and this, this whole ecosystem of constantly improving, or we could say constantly regenerating health and quality of life for all beings, that also means we need to regenerate ecosystems and landscapes, and it means we need to have a sustainable monetary system to be able to do that, including paying for and supporting all of us farmers who are doing that. So anyway, there's lots that can tie into this topic and I'm broadening my intro longer than normal. It's. It's about more than just the ecology and the landscape. It's also the financial ecosystem that allows all of that to function well, and which hasn't allowed it to function quite so well up to this point. But that might be a conversation for another day. I'm really excited to be back here and to be talking with all of you again. My guest for this episode is Aaron Silva from the University of Wisconsin, who many of you may have heard of. And if you haven't, then I'm very delighted to introduce you. Aaron has really been a pioneer in bringing about the adoption of weed control methods for organic systems, using roller crimper and using cover crop rye, but also a lot more than that. She's known for some of those things, but she's done much greater work than that. So, Erin, for those of us who are less familiar with your work, tell us a bit about your story, your background. What is it that brought you here? How did you get to be doing this work that you've been doing for the last decade?

Yeah, first, thank you for having me on. It's been a bit of a challenge to find time to get together and chat, but having listened to your podcast, I'm really delighted to have a chance to visit with you and talk together about regenerative agriculture and also all the benefits that it can bring. I've been working in organic agriculture since about 2003. I did not grow up on a farm. I grew up close to a city, grew up close to Boston. But even with my more suburban upbringing, I was exposed to organic gardening quite early on. I still remember as a child, working out in our garden, our large garden in an old farmhous that we owned as a kid and having my own little plots where I'd grow tomatoes and green beans, and walking out There and picking the vegetables and leafing through my mother's organic gardening magazines, the old Rodale magazines. So that was my first exposure to organic gardening and being familiar with growing our own food and just the joy and the work that goes into producing at a homestead farm level. But from there didn't go into my academic career thinking I was necessarily going to go into agriculture, but really had more of an interest in environmental science and ecology and understanding just how these complex systems work that are really driving the world around us. And from there had the opportunity to work, work in a laboratory at the University of Wisconsin, Madison when I was an undergrad. And at that time there was a graduate student that was a real leader in organic agriculture. Still, that exposed me again early on to organic agriculture and how it contributed positively to promoting and driving forward sustainable food systems. And from there really caught on to working in agriculture and farming and seeing the connection of growing food and ecology and just all the complex interactions that happen when we make our production choices in terms of the crops that we grow and the way that we manage our soils and the broader ecosystem of even the communities that are involved in growing that food. So it's been a kind of a circuitous journey, I guess, into agriculture, not necessarily a straightforward one. But I think that honestly that initial connection between ecology and agriculture has really benefited me as I continue to work in organic agriculture and now more in the regenerative agriculture sphere.

You know, I find it really interesting. We've been asked to work on developing curriculum for regenerative agriculture courses for 2 year and 4 year degrees by a couple of community colleges. And one of the collaborators in developing this curriculum has really emphasized that one of the fundamental differences between really understanding this different worldview is what he describes as ecological literacy. And in studying the work that he was bringing forward, it occurred to me that, you know, maybe this is something that's even missing from mainstream agriculture. It should be inherent in our agricultural worldview, but in fact, maybe we're not fully ecologically literate the way we might be.

Yeah, that's really an interesting way of looking at it. I think oftentimes when we think of the environment and agriculture, those two concepts can be at odds. And I think there's historical reasons why that is with issues with respect to land management and policy and prioritizing how, how land is utilized and obviously different complex aspects of regulation and other issues that I think we still face as a agricultural community. But I think that the recognition over the past decade of the critical aspects of biology when it comes to the agricultural ecosystem. I think that has really helped to connect how agriculture and ecology come together. I think over the decades prior to this recognition of how critical biology is to a well functioning agricultural system, we thought of agriculture as very much more of a linear type system where we put in a input and then there was a certain direction, action. But I think that we recognize more and more how our actions on the land and how we manage our soils and manage our plants really more mimic how we manage, even from a human health standpoint, our own health. And what we can do to promote the soil biological ecosystem like we do promote our gut health by the foods that we eat, by promoting the plant immune system, by making sure that the plant has what it needs to be able to avoid stress, the same way that we do what we can to avoid stress and again eat what we can and put ourselves in a condition where we can better fight disease and illness. Those same parallels exist in our agricultural system. And it's certainly more complex than applying an input and then having a plant response that is more driven by a chemical reaction, so to speak. And I think that parallel, I think, has really kind of connected the complexity of what our management and how do we optimize management to increase this function with respect to biology and plant performance as it relates to plant resilience and the ability to be able to naturally resist some of the stresses that we face in our agricultural production systems.

You raise such an important perspective as farmers, and even in our work at advancing eco agriculture, we see this constantly. There is this expectation of inputs equals certain outputs, kind of this linear mechanistic worldview, if you will, that if I apply X, I need to be confident of being able to observe result Y. And that becomes a lot more fuzzy in a biological world rather than in a chemistry world. And there's lots of cumulative stuff that can happen or cannot happen. And I find it interesting as obviously we live in a world where the changes that we want to make or need to make in our systems need to deliver economic results for growers. That's fundamental. But sometimes the route to those results is not linear. And that's, I think, a growing awareness, but something that newcomers to the space still really grapple with at times.

Yes, I mean, I very much agree. Having done research for over 15 years now, coming on to 20 years in organic production systems, it's an aspect of these systems that make this sort of research exciting. But I think it also presents a challenge with respect to how we do the research and then how that translates to Farmer recommendation. And I've certainly seen that with respect to the research that we do with respect to soil management, but also with the work that I've been doing with organic no till as well. And I think as we look at how these management practices translate in these more biologically, ecologically driven systems, it's so context dependent. And I know as we look at this, behavioral health principles, I mean that is being added on that context is critically important when we think about what we're doing and how we're doing it. But it's not as simple as I think some of the trials that we see with a synthetic pesticide where you do X, you get Y result. Depending on the conditions of a given year or the inherent biology that is present or the genetics of the plant, the outcomes can be different. And that is not necessarily a bad thing. But I think as we look at how that translates into best management practices and communicating with farmers the likely outcomes and reducing risk, it's an important thing to consider. And I think we need to change the way we think about making recommendations or what our expectations are.

Well, it is when we consider the context that means, if we translate what that really means, it means we need to change the parameters that we're studying or the parameters that we want to implement, the practices or products that we want to use on our farming operation. From an individual single focus to a multi factor focus, and this quote, unquote, the scientific method has evolved over the last seven or eight decades to largely focus, at least in this context, to largely focus on single factor analysis. We're going to just change this one thing and then see how everything else changes. But in reality that's not how living systems work. You can't. It's impossible to change just one thing. If you change just one thing, then the whole system moves. And this is when we look at research. It's a lot more challenging to do systems research in agriculture than it is to do single factor research. And yet for this different paradigm to really thrive, that is what is needed both from a research perspective and from a practical implementation perspective.

Absolutely. And I think that as we are able to develop frameworks in which we can better capture performance over a larger set of environments and have these communities of practice where we can bring observation as well as replicated trials together, that we can start to be able to see patterns and trends. But it certainly is a deviation from how we've traditionally done research at the university, which tends to focus more on a single site and limited number of environments and limited time Frames. And this certainly isn't always the case. So I don't want to oversimplify, but I think that like you're saying, I mean, with these ecological systems, I think that the timeframes that we need to be making observations over and the number of environments we need to be considering are just multifold, even from what we have been doing more in our traditional agricultural research approaches. So it's, it's, it really kind of takes. Takes that need to another level, again, particularly with respect to biology, where biology is going to evolve and it isn't static. So as we look at making these changes in the way we manage our soils and what we're doing with respect to crop management, the diversity of crops we grow, the COVID crops we use, how we're managing residues, that is not only going to change depending on the year, depending on the precipitation or temperature, it's also going to change as that system matures and the biology continues to evolve in response to management.

So when we consider all of this context, I'd like to bring the conversation back around to your story and the impact that you've been able to have in this overarching ecosystem. Because I know that there are many farmers who are good friends of mine across the Midwest who give you a lot of credit for stimulating them on their journey or kind of triggering them to take the next step and to really go down this pathway, particularly in regards to organic no till. I know that others have also done work and helped popularize it. But it's my perception that you, perhaps more than anyone, helped to really figure out the details of how do we make this system work in an organic no till environment. Can you tell us a little bit about that and how all that came to be?

Yeah. So I actually first started to work in these systems, interestingly, in a very, very different environment, when I was first on the faculty at New Mexico State University, and that was back in 2003, and when I was brought onto the faculty at New Mexico State University, I just by chance had the opportunity to really dive deeply into organic agriculture with being able to teach a class in organic agriculture that was based on a working student CSA farm that was managed organically and also had Support even almost 20 years ago, to do organic research and receive some of the first federal funding that was designated to forward organic agricultural research. And working in New Mexico, that was quite a different environment than what we have in the north central region, the upper Midwest. And I was working in irrigated agricultural systems in an arid environment with very poor soils and the way because of the issues with water, oftentimes the soil was left bare. Between the intensive cropping that was done, it was a lot of vegetable cropping that I was working with, onions and chili and cotton production. And even again 20 years ago, as I was driving around southern New Mexico, I mean, there were times where we could just see the soil literally moving across the land. And the profound soil loss that was stimulated by the winds and just the movement of the soil was, was quite, quite profound. So I was actually inspired by work from Ron Morse at Virginia Tech University. And he actually was one of the first people to look at using cover crops to reduce tillage and vegetable systems and, and looking at trying to design strategies to keep our soils in place and to prevent this erosion. That again, was quite visible to try to take some of the concepts that he was working on in Virginia and bring that to the irrigated systems in New Mexico. So even there, in a very, very different environment, had used cover crops in both the ways that we're doing now with roller crimping as well as winter killed cover crops and then direct transplanting of chili peppers into the killed residues. So it was really early on in my career that I started to work in these systems. And when I moved to the University of Wisconsin in 2006, there was another professor here, Dr. Josh Posner, who was. Was very much an engineer, a pioneer in sustainable agriculture and organic ag research early on at University of Wisconsin Madison. And he had just within the past couple years before I had came to UW Madison, had bought a Rodale roller crimper. So between having those experiences already at New Mexico State and that interest, and then coming to a university that had access to the equipment to allow me to do this in the systems I would be working in in Wisconsin, our larger row crop and dairy systems. Began working in no till research for organic producers in 2006, 2007. So at that time I had the pleasure to work with Jeff Moyer from the Rodale Institute. So that really gave me a unique opportunity from someone that was an early leader in this research area and really was a mentor in terms of how to translate the research he was doing in Pennsylvania with the Rodale Institute to Wisconsin. So I really had several circumstances line up that really created an ideal situation to begin this research and begin it in a way that really got me off on a solid footing. And through my work, not only at our research station, but with farmers, I was able to learn a lot fairly quickly.