Dr. Erin Silva, associate professor of organic and sustainable cropping systems at the University of Wisconsin, joins us on this week's edition of the Cover Crop Strategies podcast, brought to you by La Crosse Seed.
Dr. Silva breaks down some of the big developments at the university's Arlington Research Station, including a look at how winter triticale is being used as a cover crop. We'll also discuss the latest research on cover crop no-till corn systems.
Dr. Silva takes an in-depth look at the potential benefits of interseeding into soybeans, getting covers established early and much more!
The Cover Crop Strategies podcast series is brought to you by La Crosse Seed.
Solving the SOIL HEALTH Puzzle? La Crosse Seed Has You Covered.
La Crosse Seed has put together a leading conservation seed platform by offering respected cover crop and native seed brands, plus practical support along the way. Quality products, helpful tools and expert advice make La Crosse Seed a strong partner with the pieces you need to succeed in this growing market. Dealers: Learn more at soil1st.com, or call 800.356.SEED.
Full Transcript
Noah Newman:
Welcome to another edition of the Cover Crop Strategies podcast. I'm your host Noah Newman, associate editor. Before we get started, let's take some time to thank our sponsor. Solving the soil health puzzle? La Crosse Seed has you covered. Cover crops are an important piece to future profit, but it takes work and is puzzling at times. La Crosse Seed delivers quality Soil First cover crop products, plus training and tools to help you succeed. Whether you're looking to grow your cover crop seed business, get product tips, or find a local Soil First dealer La Crosse Seed is ready to help learn more at soil1st.com. That's soil1st.com. Or call 800-356-seed.
Noah Newman:
Big thank you to Dr. Erin Silva, associate professor of organic and sustainable cropping systems at the University of Wisconsin for joining us on this week's edition of the Cover Crop Strategies podcast. So there's a lot going on at the university's Arlington research station and Dr. Silva is here to break down all the big developments, including a look at how winter triticale is being used as a cover crop. We'll also discuss new research on cover crop no-till corn systems. We'll talk about the potential benefits of interseeding into soybeans, getting covers established early, and much more.
Noah Newman:
All right, Dr. Silva, let's start with your background. Let's get the Dr. Silva origin story. Do you have a farming background? What got you interested in agriculture?
Dr. Silva:
Well, thank you for having me on the podcast today. I did not grow up with a farming background. I grew up as a suburban kid, grew up outside of Boston, but I did grow up in an area where I was surrounded by a lot of undeveloped land. So I did have an appreciation for the natural landscape and being outdoors. And as I moved into pursuing a degree at the university I really wanted to focus the work I was doing on the natural environment and working outdoors, and fell into agriculture by accident, quite honestly, by having the opportunity to work in a laboratory in the horticulture department at UW Madison and realized through my work there that farming and the work that farmers do have a profound impact on our landscape and the ability for farmers to positively impact our natural lands and our environment is tremendous. So pursued agriculture as a way to bring together that passion of working outdoors and working to be a steward of the environment and bring that together with food production and the amazing work that farmers do.
Noah Newman:
And so now at the university of Wisconsin, Madison, you direct research on no-till organic practices. So how did you get into that and kind of give us an update on what you guys are working on at the moment?
Dr. Silva:
Yeah, so it's been a long journey into no-till organic for me. Prior to coming onto UW Madison in a faculty position, I was working at New Mexico State University, and that was quite a different environment down in New Mexico. It was a very arid environment. There was a lot of open soil between cash crop planting and regularly experienced events where you could visually see soil moving across the highway and the tremendous loss of those valuable soil resources.
Dr. Silva:
So while I was working down in New Mexico, I started to explore how could we use cover crops to essentially armor our field and protect our soil and began work in cover crop based no-till, and not necessarily in an organic context, although we did look at multiple ways of managing those cover crops, the use of herbicides to terminate cover crops, as well as winter killing those cover crops during the colder periods throughout the winter. But as I moved to a position at UW Madison more specifically focus on organic, I saw that through the work of the Rodale Institute and through other pioneering research programs, that there was a great opportunity to translate those cover crop based reduced tillage practices into organic production systems to mitigate one of the more challenging aspects of organic production, particularly with respect to soil stewardship, the tillage and cultivation that's needed for weed management.
Noah Newman:
I actually read on your website, the Wisconsin website that Wisconsin has the second highest number of organic farms in the US and ranked third in total organic acres. Just from your point of view, why do you think that trend has really caught on here in Wisconsin?
Dr. Silva:
That was Wisconsin has been a national leader in organic for decades now. And even prior to the rollout of the National Organic Program in 2002, Wisconsin had really a strong, strong history in organic farming, including the evolving of the Organic Valley crop cooperative that really started even a decade more prior to the National Organic Program. And I think there's a variety of reasons for that in Wisconsin in general, as we hit Earth Day today. We've had a long history in environmental stewardship with governor Nelson, who founded Earth Day.
Dr. Silva:
So I think there's been just that long history of environmental consciousness in Wisconsin. We've always had a very diverse agricultural landscape here, still do, where we have dairy farms and livestock farms, green farms, vegetable farms, and that integration of livestock and that access to manure really strengthens the opportunity for organic farming. We have smaller farms here, partly by nature of our landscape. We typically have a bit hillier landscape where there isn't necessarily as much of an opportunity for larger, flatter fields like we do in other areas of the corn belt. And we have a winter, we definitely have a winter here in Wisconsin, which really benefits it's organic farming as it helps break up pest and disease cycles. So I think there's kind of a confluence of factors that have led to Wisconsin being a continued leader in the organic sphere.
Noah Newman:
Yeah, definitely a long winter. I mean, it was snowing the other day here in late April and then it was 60 degrees the other day, and now it's pouring and rain. So I don't know how much work you've been able to get done this week, but what type of cover crop trials are you currently working on at the Arlington research plots?
Dr. Silva:
Well, we're doing quite a lot of work looking at different aspects of managing organic no-till. We're continuing some innovation with respect to cover crop based no-tilling soybeans, which is the phase of the crop rotation where we've had the most consistent success using terminated cover crops to suppress weeds and reduce, or eliminate really, the need for cultivation for weed management. Trying a few different new spins on that research using triticale as a cover crop. Winter triticale that was planted last fall. And actually instead of roller crimping that crop, we will be harvesting that crop as a haylage in mid-May and still not disturbing those fields, but then drilling soybeans directly into that triticale stubble. So be on the lookout for those results, and if you're interested, certainly can come to our field day this summer at Arlington.
Dr. Silva:
Trying some new work with no-tilling spring cereal grains into alfalfa, using alfalfa as a kind of a living cover crop and doing some suppression methods for alfalfa and trying to establish spring grains into that crop, doing work continuing our effort to develop cover crop based no-till corn systems. So looking at ways through fertility management and management of both terminated covers and cereal rye, as well as a living cover of red clover to get adequate weed suppression, as well as attain our target yields for corn.
Dr. Silva:
And then finally we're doing quite a bit of work with interseeding. So looking at ways to interseed cover crops into soybeans so that we can eliminate the need for cultivation and the soil disturbance events after soybean planting, as well as looking at ways to successfully interseed cover crops into corn, at about the V3 stage. So again, eliminating some of the soil disturbance passes that are needed for weed management and getting earlier establishment of diverse cover crops So we don't have to rely on our shorter growing degree days after corn harvest. So lots of cool things going on.
Noah Newman:
Yeah. You have a lot going on it sounds like. It's interesting you brought up interseeding because I actually just did a podcast with Dean Whiteman, a farmer out here in Wisconsin recently, and he talked about interseeding. So for our listeners, what exactly is it? And what kind of benefits could you see from it?
Dr. Silva:
Yeah. So interseeding is a practice where we're looking at ways to establish cover crops, whether it's single species or diverse mixes, earlier in the season so that we're able to get those cover crops established and already have them germinating, root systems put down and established prior to corn harvest. So one of the challenges we face here with respect to diverse cover crop systems in Wisconsin is that upon harvesting corn, whether it be for silage or grain, typically it's not happening until September or even October, which really doesn't allow a lot of time for diverse cover crops to establish. Now cereal rye, we pretty wide window in terms of when we can plant that seed and still have a reliable cover crop established. But when we're looking at adding diversity and putting in legumes or brassicas, really that planting date of late September and October is just really too late to get anything established.
Dr. Silva:
So if we can get those cover crops established earlier, that offers a really a wide range of different options. And that allows us to have that soil protected as soon as that cash crop of corn comes off the field. So a lot of the research related to interseeding emerged from the east coast or the mid Atlantic region and Penn State University has been a leader in this research and even has developed specific equipment to allow for interseeding. But that research had led to recommendations of planting the cover crop at about the V4-V5 stage of corn. And when we saw that recommendation brought out to the Midwest and Wisconsin, what we typically saw was that planting that late, the cover crop didn't get enough sunlight reaching down into the corn canopy to really allow for good establishment and a good root system to be put down.
Dr. Silva:
So even if that cover crop seed germinated, it typically disappeared by the end of the summer. So a lot of this came through farmer innovation and including with a lot of farmer-led watershed groups and a lot of the innovative farmers that we have throughout the state and the crop consultants were working with those farmers. They saw that pushing the planting date a little bit earlier, so more towards the V3 stage of corn, allowed for a longer window for sunlight to reach down into that canopy and allow those cover crops to establish and allow for better persistence of those cover crops after harvest. So that's been an area of continued research that we've been engaged in and in great partnership with farmers across the state that have put partnering trials out on their farms. So still have to keep looking at that data and seeing how sound that recommendation might be across the diverse regions throughout the state. But it's been really exciting to see, again, all this farmer innovation happening with interseeding and seeing how we might be able to adapt that system, particularly to our Wisconsin climate.
Noah Newman:
We'll get back to the podcast in just a second, but once again, let's thank our sponsor. Solving the soil health puzzle, La Crosse Seed. As you covered, cover crops are an important piece to future profit, but it takes work and is puzzling at times. La Crosse Seed delivers quality Soil First cover crop products, plus training and tools to help you succeed. Whether you're looking to grow your cover crop seed business, get product tips, or find a local Soil First dealer, La Crosse Seed is ready to help. Learn more at soil1st.com. That's soil1st.com, or you can call 800-356-seed. Now back to the podcast.
Noah Newman:
And you've done a lot of research on understanding how to no-till soybeans directly into a living rye cover crop. Let's talk about that. What are some of the keys to making that system work?
Dr. Silva:
Yeah, and I think there's a couple different ways we can look at that system. And it's been great to see the emergence of more research coming out of UW Madison, particularly out of Dr. Rodrigo Werle's lab, that have looked at what are some additional options we might have for management in conventional systems where we have herbicide as an additional tool for management. So, as we're looking at a cover crop based no-till and rolling rye in organic systems where we're really entirely reliant on that cover crop being our weed management tool. So we don't have chemical options to layer on top of the cover crop as our primary weed suppressing mechanism. So in order to completely rely on that cover crop and eliminate the need for herbicides or chemical termination, there's a few key things that we need to consider. First is that we found, not only within Wisconsin, but across other regions as well, that have really led in some of this research, as well as farmer experience, that we need to get that cereal rye cover crop planted early.
Dr. Silva:
And as I just mentioned, with some of the challenges with interseeding and the benefits of cereal rye as an option to be planted later in the fall, we know that cereal rye can certainly germinate and establish even with later planting dates into October, November, and I've heard even into December, but the problem there is that we don't get the degree of tillering we need to get the adequate weed suppression in a cover crop based no-till system. So even though we know we can plant cereal rye later, if we're using it in a cover crop based no-till system, and we want to completely eliminate herbicides, we need to plant that cereal rye early. So in most of Wisconsin, we're talking the middle of September, which is challenging in the face of designing a crop rotation that will allow for that earlier planting date.
Dr. Silva:
So oftentimes to make this system work, we have to change our crop sequence of how we're thinking about planting our crops and in which order, and we typically need to have some cereal grain in the rotation. So whether that be an oat crop or a winter wheat crop, we need to look at putting some crop into the crop rotation where we can get an earlier harvest of that cash crop and an earlier planting of that cereal rye cover crop. The other key, with respect to getting enough biomass for weed suppression, is planting at a heavier seeding rate. Oftentimes when we're planting cereal rye as a cover crop, we might be planting at a rate of about a bushel per acre. But we want to raise that seeding rate to closer to three bushels an acre in order to again get the biomass to achieve complete weed suppression.
Dr. Silva:
We need to have that ground completely covered even before we rolling crimp that cover crop. As we look into the beginning of April and see that cereal rye cover crop start to green up, we really want to see very limited bare soil. We want to see basically what looks like a green lawn of cereal rye. So that heavier seeding rate, and then finally, we need to terminate that cover crop at the right time. So again, this is a different shift in mindset. We need to wait till a stage called anthesis, where those cereal grains are flowering. You can visually see the pollen being sheded from those rye heads. And in Wisconsin, that stage is typically not reached until about Memorial Day, so that is quite a delay in planting, as compared to a typical soybean cash crop, especially in a conventional production system.
Dr. Silva:
It's not so different with organic production. So there's not that much of a change in practice there, but in conventional systems, it certainly is later. So that's where we can look at perhaps other options with respect to management around termination of seeding the cover crop, the soybeans, earlier into standing rye, at about the boot stage, and then terminating the cereal rye a little bit later. Again at anthesis, if we're solely relying on mechanical termination, we are looking at how we can integrate herbicide based tools to augment the termination, the mechanical termination of the rye, or potentially look at using those herbicides to account for perhaps a later cereal rye planting date or a lighter cereal rye seeding date. So I think there's a lot of different opportunities for continued innovation in this space and seeing how we can integrate both conventional and organic tools to create a system that gives us the benefit of these high biomass cover crops and additional mode of action for weed management, but yet brings all the tools available to the table.
Noah Newman:
What about no-tilling corn into a cover crop? What are some issues with that? Are there any new developments on that front and is there potential for that system to work?
Dr. Silva:
Yeah, that's a great question. The challenges with rolling cover crops and mechanically terminating cover crops and establishing corn, those challenges still persist. Even within lower biomass planting systems in conventional agriculture, there's a lot of interest in planting green and planting into a living cover crop and doing later termination, but as compared to soybeans, we've seen continued inconsistencies in the performance of the corn crop when integrating those management strategies. Some of that seems to center around fertility management, and we've certainly seen that within our organic roll crimp systems using corn, that the corn is much more sensitive to nitrogen tie up and looking at ways that we can ensure that we are applying in to meet corn demand, that that's not being tied up by those high seed end ratio cover crops or the uptake of nitrogen by those cover crops.
Dr. Silva:
So how can we through side dressing and continued precision application of nitrogen in these systems be able to mitigate some of that variability. In organic systems and certainly conventional systems as well, we see some challenges with different pest dynamics, particularly with army worms in these systems that tend to impact corn more than soybeans. So that's another consideration as well. And whereas soybeans are extremely elastic in respect to being able to achieve high yields even with lower plant populations, corn as a crop certainly doesn't share that same trait. So ensuring that we have good stands and good stand establishment through these high biomass cover crops through equipment modifications or other strategies is another challenge that we continue to face.
Noah Newman:
Now, this is called Cover Crop Strategy, so I'm going to ask you this. Are there any cover crop topics or news right now that really has you excited?
Dr. Silva:
I think that there's just a continued recognition of the role that cover crops can play, with respect to soil biology and creating resilience systems that improve soil health, improve nutrient cycling, and ultimately lead to a lessened reliance on input. So whether it's within conventional or organic systems, learning how we can best design cover crop mixtures, how we can best design continued cover crop systems to meet not only our agronomic goals, but the soil health goals that we have in this agricultural community, I think that there's just so much learning going on there, and co-generation of knowledge from not only the research community, but the farmer community, the crop consultant community, and the broader Ag industry. It's really exciting to see the recognition of the role of cover crops and soil health within regenerative agriculture more broadly.
Noah Newman:
And you mentioned you had a field day coming up this summer, did you say? Out at the Arlington research plots? You want to talk about that a little bit? When is it, how can people sign up, and what are the benefits of attending a field day event like this?
Dr. Silva:
Yeah, so our field day is scheduled for August 30th. In that field day at the Arlington agricultural research station, in Arlington Wisconsin, we highlight our organic research that is ongoing through the college of Ag and life sciences. So we invite farmers and industry folks to come out and see the work we're doing with cover crop based no-till, interseeding, and some other diverse crop production strategies as well. So we will be promoting that a bit more as the summer goes on, but if you are interested, you can certainly look at the Arlington Ag research station website and get more details. But we certainly welcome farmers to come out and see what we're doing. And we also welcome the input from farmers as well. Again, recognizing all the innovation that's that's happening on farms already.
Noah Newman:
Well, Dr. Silva, I really appreciate the time. Thanks for joining us. Before we let you go, anything else you want to share or touch on?
Dr. Silva:
Through our work we've seen the benefits of cover crop based no-till and cover crop based management, particularly with soybeans. There's some general principles that farmers should follow if they want to adapt these practices to their land. But I certainly encourage farmers to educate themselves and find peers and other mentors if they want to try some of these innovative practices on their farms.
Noah Newman:
And once again, thanks to Dr. Silva for joining us. Great conversation there on today's podcast. Before we go, let's thank our sponsor one more time. Solving the soil health puzzle? La Crosse Seed has you covered. Cover crops are an important piece to future profit, but it takes work and is puzzling at times. La Crosse Seed delivers quality Soil First cover crop products, plus training and tools to help you succeed. Whether you're looking to grow your cover crop seed business, get product tips, or find a local Soil First dealer, La Crosse Seed is ready to help. Learn more at soil1st.com. That's soil1st.com or call 800-356-seed. And once again, remember for all things cover crops, head to our website, covercropstrategies.com.
Post a comment
Report Abusive Comment