Podcasts

Weed Control in Organic Farming w/ Dr. Joel Gruver, PhD

Interview with Joel Gruver, Organic Research Program Director at Western Illinois University

Show Notes


On this episode of Organics Unpacked, we take a look at different techniques for weed control and managing weeds in organic farming. Our guest is Dr. Joel Gruver, Director of the Organic Research Program at Western Illinois University. In addition to teaching at the university, Joel conducts industry-leading research on an organic research farm, which he has overseen for over 15 years. His research interests include conservation cropping systems with a focus on cover crops and organic grain production.

Learn more about Avé Organics: www.aveorganics.com 

Learn more about Joel Gruver at Western Illinois University: www.wiu.edu

Connect with our guest on LinkedIn

#organicfarming

Podcast Transcription


TOM: Hello, everyone. Welcome to Organics Unpacked. Today’s guest is Dr. Joel Gruver, Director of the Organic Research Program at Western Illinois University. Today, we are discussing techniques for managing weed control and weeds in organic farming.

INTRO: Welcome to Organics Unpacked, a podcast for the business-minded organic grower — an interview podcast where we hear from the top experts in the commercial organic industry — with a focus on the business elements of organic growing both in and out of the field. You will gain insight and grow your operation. This show is brought to you ad-free by Avé Organics, a Wilbur-Ellis company. To learn more about Avé Organics, visit our program notes. In the meantime, enjoy the show.

TOM: Dr. Gruver, welcome to the show.

JOEL: Glad to be here.


Challenges of Weed Control


TOM: Joel, I often hear, in organic farming, one of the most challenging things is always weed control. When you ask organic farmers, What are the challenges?’ weed control seems to always come to the top. Is that right?

JOEL: I would agree. I think that there are some things where there are more direct substitutes. So, for example, you can have organic fertilizers substituting for conventional fertilizers, and there are organic fertilizer products that can be managed in similar ways to conventional fertilizers. There are not organic herbicides that function anywhere close to the performance of conventional herbicides. So the approach to weed control in organic systems really can’t be a substitution approach. It has to be just a fundamentally different approach than the way most conventional farmers manage weeds.

TOM: So people that are kind of transitioning from more of a conventional style to an organic style probably are in for a rude awakening when it comes to managing their weeds, right?

JOEL: They are, but one of the challenges is that the weed control may actually be fairly easy during the first several years. If they have been very successful or the previous farmer has been very successful in controlling weeds, the soil seed bank may be quite depleted. So part of the root transition may be that it seems like they have practices that are effective for a couple years, and then things get worse and worse. That’s really, I think, the big challenge. If organic weed control is not done effectively, your problems get worse and worse, and it really becomes something that will drive some farmers out of organic farming. And I guess the flip side is an indication that you’re really doing organic farming well is that your weed management gets easier, that you have more effective control of weeds. It’s never going to be just completely straightforward. There will be differences from year to year with different weather and different issues that can come up. But if your system isn’t starting to stabilize and actually improve in terms of your weed control, you really need to rethink your system. You have some problems in your rotations or your equipment that need to be addressed if your system isn’t stabilizing or getting better. 


Organic Research at Western Illinois University


TOM: So, Joel, before we get into weed control, how about you talk a little bit about your research plots and where you are at your university?

JOEL: Sure. So I’m at Western Illinois University. The main campus is in Macomb, Illinois, which is about an hour-and-a-half south of the Quad Cities, about three hours north of St. Louis. But our research farm — the organic research farm — is located about 15 miles away from campus. It’s not right next to campus, and it’s not owned by the university or by the state. We rent private land that has a history of being farmed organically, and it was identified about 30 years ago as a good site for doing organic research. Originally, it was pesticide-free research. It wasn’t specifically designated as organic, but we transitioned to organic. I guess the first organic field was certified in 97, and it became fully organic in 2009, which was the second year that I was there. I’ve been with the program for 15 years, and my principal activity at the university is teaching undergraduate classes. But this research farm has been a crash course in authenticity when it comes to organic, doing organic outreach. I have to figure things out. Otherwise, I only have disasters to talk about. 

We’ve figured a lot of things out over the last 15 years. I’ve had great collaboration from a technician, Andy Clayton, and he’s thinking about retiring. I have to figure out how to keep things going, but it’s really been a collaborative process between my technicians, student workers and the local farmers that have allowed us to grow about 65 acres of organic crops each year. And most of it is large-scale replicated research plots, maybe about 10 different experiments. Our main crops are corn and soybeans, but we also grow small grains and smaller amounts of some other things like sunflowers or pumpkins. We are using primarily the same types of equipment that local farmers would be using, mainly because we rent the equipment from the local farmers rather than owning it. It’s an adventure each year, but it creates authenticity for me, both in the classroom when I’m talking to my students. They know that I have gone through the same weather challenges that their families have. And it also creates authenticity when talking to farmer meetings because I can talk about my experiences in the field.


Different Methods of Weed Control


TOM: Well, that makes it really important as a guest on this show because we really like to talk to people that have been out in the field. They don’t have the latest and greatest of everything. Obviously, like you, a lot of people are looking for equipment and kind of make do with what they have, so it’s great to have you on the show today. In weed control, mainly, we’re talking corn and beans with you today. What are the different resources that an organic farmer has for weed control?

JOEL: Well, the traditional perspective is that your main tool is steel, that you terminate the weeds before you plant your crop. So you get a clean slate by tillage initially, and that might be several passes of tillage. One of the key things that most organic farmers will tell you is that you need to have several flushes of weeds in the spring that you terminate prior to planting the crop. In a sense, what you’re doing is you are reducing the weed pressure so that, after the crop is planted, fewer weeds will germinate because each season only a limited percentage of the total soil seed bank is going to germinate. And if you can have many of the weeds that are likely to germinate that season germinate before you plant the crop, and you clean them up, you use tillage to terminate them or possibly use flaming or some other technique without tillage. But if you can terminate weeds before you plant the crop, you will have less weeds to control after the crop establishes. There are many different types of steel that can be used, but I think one of the most important concepts is that your steel — the exact same tool — can work very differently depending on the soil conditions, depending on how you’ve set that piece of equipment and depending on the timeliness of when you use that piece of equipment. 

While steel is very valuable, it’s something that can be very ineffective or very effective, depending on many different things that create the context for how you’re using that steel. The context is partly things that the farmer doesn’t have much control over: the weather perhaps, the soil types that he’s working with. But the farmer does create the cropping system that, if well-designed, creates a good soil structure, which will interact with the steel in the right way so that the soil will crumble off of your steel. Soil will shatter from the weed roots, and the weeds will rapidly desiccate. If the soil structure is poor, the steel doesn’t work nearly as well as it could. So the main way that you create good soil structure is with the right cropping system, and that’s your sequencing of cover crops and cash crops and when you choose to do the different field operations, being very sensitive to not tilling when the soil’s too moist. If you don’t have good soil structure, your steel is not going to perform nearly as well as it could. 


Cropping Systems for Weed Control


TOM: That’s interesting. So we have steel as one method of weed control. Are there other ones?

JOEL: As I was laying out as the context, the other methods, I think, are the cropping system methods. And of course, there are some others. The steel, I’m speaking of as a direct termination method. In contrast, in conventional agriculture, herbicides are a direct termination method. There are some organic herbicides, and there are some methods such as flaming or weed zapping that can terminate weeds without tilling the soil. But I think probably the most important piece of effective weed control is the cropping system, that, basically, you’re trying to do two things. You’re trying to maximize the competitive advantage of the crops, and you’re trying to suppress the weed pressure so that the number of weeds and the vigor of the weeds that germinate after your crop is established is lower. Basically, you could think about: your direct control practices aren’t going to kill everything. Maybe they will get 90% of the weeds or 95%, and that remaining 10% or 5% can be a very low number. Or it can be a very large number. Even if you achieve 95% control, if you have hundreds of weed seedlings per square foot, you’re still going to have way too many weeds in your field to not have an economic impact on those weeds. 

But if you have reduced the weed pressure with your cropping system, and then you get 90 to 95% termination with your direct control methods, then your weeds are spread out across the field where they have limited impact economically. They don’t interfere with harvesting, and you have a real option of walking the field. Let’s say manually walking the field, or you could use a tool like a weed zapper, which can terminate weeds that are taller than the crop. And if those weeds are spread out a weed here and there, the weed zapper can work highly effectively, and you can go quickly across the field. If you have multiple weeds per row foot — let’s say you have 3, 4, 5 weeds per row foot, as many weeds as the crop maybe — the weed zapper is not going to work effectively. You’re going to have to go extremely slowly across the field. If you were pulling the weeds by hand, it would take 5, 10, 20 hours per acre, and that’s not an effective use of your time. So, when you get good weed suppression by the cropping system, then the steel can do the job that it’s capable of doing and leave just a small number of weeds. Then your other cleanup methods can take care of those weeds, or you can decide that the small number of weeds doesn’t matter.


Weed Pressure in Organic Farming


TOM: All right, so that makes sense. If you can start out with 95% less weeds or 80% or whatever, then you get some effective weed control with your steel. It makes sense that you are much, much further ahead. So, when you’re in an organic system, how is your weed pressure? I know your weed pressure is more, but is your weed variety different, typically, than what you would see under a conventional system where you’re using herbicides? Or are weeds weeds, and they’re going to grow regardless of the setting?

JOEL: That is an interesting question. I think the selection pressure is different. Whatever your methods of suppression are, they are selecting for things that are tolerant of that suppression. And I think, in chemical weed control systems, we still have most of the weeds being effectively controlled. So what we see are just very low diversity of weeds, a small number of species that have chemical resistance, so the weed has actually evolved resistance to that chemistry. Or maybe because the weed was damaged, or something caused lack of uptake of the chemistry, you normally see some weeds in conventional fields, but the diversity is small. In organic systems, you tend to see more diversity of weeds. I think that’s not a problem. What’s problematic when you see an organic field that is just completely dominated by one weed — let’s say giant foxtail — you just know that things did not come together well, that there was a problem in how that system was assembled. And obviously, certain weather conditions or mechanical breakdowns can contribute to those problems. I would say having greater diversity of weeds in your field but lower numbers is what you see on farms that have effective organic weed control. Whereas if you just see a single species being dominant and lots of that species, like giant foxtail, there’s definitely a problem with the system that needs to be carefully considered. How can you change the system that is creating an opportunity for that one weed to be so dominant?


Crop Rotations & Weed Pressure


TOM: All right. Let’s start with the rotation and its impact on weed pressure. Tell us what you’re doing to start that season out with as low weed pressure as possible.

JOEL: We try to have at least three crops in a rotation and sometimes more. I normally think about crop sequencing rather than crop rotation, with the idea being that I want to have a system that’s flexible enough that I can respond to the market or, in my case, respond to the need to have a different experiment in a particular field. What I want to do is alternate cool and warm-season crops as much as possible, and that is challenging. The overall concept of crop diversity is challenged by the fact that the market diversity is not really there. The revenue potential is just so much higher for your warm-season crops — your corn and your soybeans — than it is for your cool-season crops. If you have the mentality that you want to maximize revenue every year, you’re going to grow mostly corn and soybeans. 

If you have a longer-term perspective, you’re going to recognize that you will have more opportunity to have stability in your system to have more revenue in the long run if you have these cool-season crops — like wheat, like oats — that will not bring as much revenue but will facilitate weed control and fertility and other things that are valuable for the warm-season crop. A standard rotation would be: we would have corn, soybeans and then a small grain. Then, after the small grain, we would go back to corn. Between the small grain and the corn, we would definitely have a cover crop, and often, basically, we have two options there. We would have red clover or some clover mix that would be planted with the small grain, so it’s already growing. When we harvest the small grain, the red clover or the red clover mix is already established, and we might flip the weeds once or twice before winter. But we would have the benefit of essentially no summer annual weeds going to seed, and we would have the benefit of the soil fertility — the nitrogen from the legume and the improved soil structure — from essentially having a whole season without any tillage. 

TOM: Okay. 

JOEL: After the corn crop, if we go directly to soybeans, which is fairly common for us to do, that is less ideal because we have a warm-season crop following a warm-season crop. So the same weeds tend to fit into both crops. We think about several things that we can do to add a little more diversity. We either would plant a cereal rye cover crop following the corn, preceding the soybeans, or we might plant an oat cover crop in the spring preceding the soybeans. But the idea is we want to get something planted that’s going to improve the soil structure and potentially also suppress weed germination the next season in the soybean season. If we can’t get a cover crop planted between the corn and soybeans, the most important thing is just to make sure that we manage the corn stalks and the soil structure in a way that the soil has good tilth and will flow when we are doing our soybean field operations. If you have too many corn stalks, they don’t flow well through your cultivation equipment. And if you beat up the soil too much — let’s say with spring tillage of damp soil — then you end up with this chunky soil, that you don’t maybe establish as strong a soybean stand. Then the soil doesn’t flow well, and the weed control is poor. It’s possible to have the soybeans following corn without a cover crop, but the cover crop in the middle, in between, really helps with having better soil structure that, then, allows your steel to perform more effectively.


Mechanical Methods of Weed Control


TOM: Okay, so the one really leads to the other. That brings us to the steel. What are the different varieties of mechanical control that you use in a field? Rotary hoe, things like that?

JOEL: Yeah, so basically there are two categories. Well, maybe three categories. You have the first. The first operation is preparing the seedbed. You want to maybe think about two variations on preparing the seedbed. The first idea is you want to get a flush of weeds. Get as many weeds to germinate as possible. That’s going to be a tool that shatters the soil and maybe even firms the soil a little bit. But your final pass, right before planting, you want to have that be shallow but sufficiently aggressive that it kills all the weeds so that everything is clean when you plant. Then your initial weed control starts with what I call blind cultivation. Many people use that term, but that’s just a term that applies to rotary hoeing or tine weeding or drag harrows: various tools that you begin before the crop has even emerged. Then you continue for maybe several weeks after the crop has emerged, and you’re trying to disturb the whole soil surface very shallowly with two objectives. 

One is to kill little, tiny weeds that ideally have not even even emerged yet. They’ve germinated, but they haven’t even reached the surface because a weed is much, much stronger as soon as it turns green. When it’s white, that’s when it is most susceptible to just a little bit of mechanical disruption, and you can kill a lot of weeds very easily. The other thing that the blind cultivation does is it just leaves the soil surface shattered in a way that you don’t have good soil/​seed contact. So you’ve planted your crop deep enough. Let’s say you’ve planted your crop two inches deep. Your blind cultivation is just working on the top inch so that you’re keeping that zone basically unfavorable for weed germination until the next rain. And you don’t know when that’s going to be, but even if it’s just three/​four days, if your crop gets a jump three or four days or a week or two weeks on the weeds, then that will make the next. The next set of processes is row cultivation, where you’re being very targeted to not damage the crop in the row but to control weeds in between the rows. And the row cultivation really depends on your crop having a jump on the weeds, having a size advantage. If your blind cultivation has been effective, your row cultivation has the real opportunity to be successful because you have the size differentiation between your crop and the smaller weeds.


Blind Cultivation in Organic Farming


TOM: So, for clarification, blind cultivation. Does it mean, I think there are weeds out there. There are probably weeds out there, but I’m just going to go ahead and till?’ What’s the meaning of blind cultivation?

JOEL: That is a good question. I don’t know the exact origin of the word, but the way I think of it is blind means that, at least when you’re starting, you’re not seeing the rows, the crop rows. Even after the crop rows are visible, you’re not trying to specifically avoid disturbing the row zone. A blind cultivation tool is going right over the row, and either it’s disturbing the soil before the crop has emerged. Or it’s disturbing the soil shallow enough — and the crop is tough enough — that the crop is just basically getting beat around a little bit, but the crop is not getting uprooted. The crop is not getting sufficiently damaged that it’s a long-term problem. One of the key things with blind cultivation is it does take out some of your crop, so you want to plant. Most organic farmers plant a little higher population with the intention that, to get good weed control, they need to sacrifice some of their crop. Hopefully not too many, but it’s worth losing 10% of your crop if you can get 95% of the weeds.

TOM: All right. Yeah, it’s interesting to me that we always talk about, in conventional agriculture, we ought to create a good, firm seedbed for our crop. Then we don’t really think about the rest between the rows. Whereas organic farmers think about, Okay, I need to create a good, firm seedbed for my crop. But I need to kind of create this bad seedbed between the rows, so we don’t get a lot of weeds to grow.’ Is that right?

JOEL: Yeah, well, I think the analogous concept in conventional ag is using residual herbicides, where you’re creating a zone that’s unfavorable for germination of weeds using chemistry. What we’re doing in organic farming is primarily creating a zone that’s unfavorable because of the physical properties, but also another key part of this is residue digestion. As microbial activity is digesting cover crop or cash crop residues, there are lay-low chemicals. There are compounds that are being released that seem to suppress weed germination, and so that’s also part of what an organic farmer is trying to create to make that surface inch. The surface inch is really where most of the weed germination occurs. There are some weeds with big seeds that germinate from deep, and those are not really controlled by blind cultivation. But most of the little seeded weeds are germinating in just the top quarter-inch/half-inch. And by creating a fluffy, loose zone at the surface, and also a zone where residues are decomposing, you have much less germination.


Weed Control after Emergence


TOM: All right, so we’ve got: working on weed control from your rotation, or you said your sequence, to then doing maybe pre-emergence tillage. Then what do we have after emergence for weed control?

JOEL: So, after emergence, we would typically have at least one more pass with a blind cultivation tool. If there are more residues, we would use a rotary hoe. If the residue level is lower or the residues are really well-sized, then we might use a tool called a tine weeder. The key concept with a tine weeder is that it functions kind of like a rake, and if there are too many residues, it will just rake the residues. So you end up with a pile, and one of the key concepts with any of these steel tools is that they can plug. If you have too much residue or the residue isn’t sized or digested, the residue plugs up your tool, and your tool stops functioning. It damages the crop. It leaves a pile in the field that makes it difficult for your next operation. That’s the constant challenge, that you want to have more residues for good soil conservation, for good biological activity. 

TOM: Right.

JOEL: But more residues can interfere with your steel. One of the big developments in the more technologically-advanced organic farms is the use of guidance systems, GPS guidance. And what GPS guidance allows you to do is to watch the crop, watch the cultivation process so much more carefully. You can look backwards. Cultivation requires that you drive very straight. If you have to be doing that visually, you cannot be looking back, or you have very limited opportunity to look back. If you are able to let the tractor steer itself, then you can watch, and you just have so much more opportunity to avoid the plugging but also just see that the cultivation is working properly. Even without plugging, you see how the soil is blowing, and you’re able to make the adjustments. At our research farm, we often have two or three people involved when we’re cultivating. My technician will be driving the tractor, but frequently I’m jogging along behind, watching the cultivation process and making sure that we stop immediately if there’s a plug. Or making sure that if there are some weeds that aren’t getting cut, if we can make a simple adjustment, we make that adjustment quickly. We might even have a student worker riding on the tractor, also watching from above. Those types of things, I think about: is that practical? Well, for our research purposes, I think it’s necessary. And what farmers who are more technologically advanced can do is they can use various technologies to provide the same type of observation that we’re providing with eyes. Sensors can do some of those things.


Guidance Systems for Weed Control


TOM: Joel, do you have guidance systems? I know that you rent all your equipment from your neighbors, but are you using guidance systems in your weed control system?

JOEL: We use guidance for planting. We’ve been doing that now for about 10 years, and it’s been transformative. It just makes every other process much, much more effective. We’re using a neighbor’s tractor that has guidance, but we’re also using the neighbor’s planter, which allows us to plant a better stand than we were able to establish with our previous planter. Having access to more technologically-advanced equipment has really helped our weed control, and the guidance on the planter tractor is as far as we are taking it. I guess we also use guidance for some of our pre-plant tillage so that we don’t have to overlap as much when we’re doing the pre-plant tillage. But for the smaller tractors that we use for row cultivation, we’re using old-school equipment, and the guidance is the operator. But the guidance is much easier if the rows have been planted straight to start with.

TOM: Do you think that if you had row guidance, it would significantly help you with weed control? Or do you think it’s kind of a luxury?

JOEL: Oh, I think there are a lot of things that the key question in terms of whether a technology is the right way to go is the question of scale. So, obviously, we have the question of how many acres do you need to pay for the technology. But also, if you have more acres, you just struggle to get things done in a timely fashion. So you need to be able to go faster, and you need to be able to — this is a critical thing — you need to be able to have the operator not fall asleep, not lose their attention. And cultivation can be mind-numbing. It’s something where you really have to be attentive. If you lose that attentiveness, you stop being effective. And I think the precision technologies — the guidance — can allow an operator to have less stress, less mental strain, as well as physical strain, and just make the process more tolerable for more hours of the day. When the weather is right, you have to use as many hours as you can. If you’re not using those hours effectively, because it’s just too difficult to stay focused, then you’re not going to be able to operate at a larger scale. I sometimes think about: how is it possible to farm 1,000 acres organically when we struggle to sometimes get things done on 60 acres? Well, a key part is having more people doing critical processes, but also having technology that assists those people in doing those processes effectively.

TOM: I think for any of us that have done cultivation for cleaning between rows, regardless of how long ago, remember how mind-numbing it is and probably have been scolded by somebody once or twice for losing concentration and taking out a few rows here and there. So I completely understand what you’re saying, that if you’re going to scale, it’s probably something you want to think about.

JOEL: Yeah, and I think, I mean, it just fits. The farmers that want to do organic grain production on a large scale, they are the farmers that have capital, that have an interest in technology. In many cases, they are coming from a conventional background where they were using technology. Those farmers are the ones that figure out the ways to take the most advantage of technology in organic farming.


Robotics & Autonomous Tractors in Organic Farming


TOM: So have you looked into robotics or autonomous tractors?

JOEL: I haven’t personally looked at those technologies. I know that those things are already here in some horticultural crops. I subscribe to a publication called Future Farm. It’s out of the Netherlands, and they do very intensive horticultural production in the Netherlands. And of course, we have intensive horticultural production in California and Florida and places like that. That’s where I think a lot of these robotic weed control systems are already in the field, weeding our lettuce crops, things like that. Those things will probably come to organic row crops, grain crops. Organic grain crops do have a higher margin than conventional grain crops, but they still have a low margin compared to horticultural crops. 

TOM: Sure. 

JOEL: I don’t see robots taking over organic grain farms anytime soon, but I think there will be degrees of automation, which will be very helpful. One thing that we’ve even thought about is just getting cover crops planted or getting amendments applied when the crop is getting too big for us to get across the field. So, whether it’s using a drone or using a tool called the Rowbot’ that fits between 30-inch rows and just goes back and forth up and down the rows, those types of things, I think, will be coming to organic grain farms. And it’ll be coming primarily to the larger farms that are more comfortable with technology.


No-Till Organic Weed Control


TOM: All right, so a question I have to ask is: have you done any work? I know this really makes weed control even more difficult, but have you looked at all at no-till in organic farming and how, with weed control, you would do that?

JOEL: That is a great question because that is something that we basically are trying to figure out: how to do both the traditional tillage-based organic weed control and also no-till organic weed control. At our research farm, we’re doing both every year. Our first attempt at organic no-till was in 2009 in soybeans, and almost all of our no-till warm-season crops have been soybeans. We have had a few attempts: one attempt at no-till corn and a few attempts at strip-till corn. What it comes down to is I see tillage as being something, just like with crops, that I want to rotate.

TOM: Right. 

JOEL: If I could control perennial weeds without any tillage, then maybe I would be comfortable with eliminating tillage altogether. But right now — and when I say perennial weeds, I’m talking about things as simple as trees with little maple seedlings — all it takes is one season of our organic no-till soybeans, where we may have an excellent crop, good weed suppression during that season, good suppression of annual weeds like foxtail or pigweeds. But by the end of that season, we can see that there are little maple seedlings that are normally not spread across the whole field, but they’ve started to move in from the edge. And we will have dandelions, and we may have some other perennial weeds, as well. I don’t worry about those weeds that season of establishment, but I do worry about them becoming a much bigger problem the next several seasons if I don’t provide suppression. I want to do some tillage within a three or four-year sequence. The soybeans we know can be done no-till. Small grains, around half of the time we grow them no-till also. We might just directly drill into soybean stubble. But ahead of the corn, we really see that as the opportunity that provides the most return on investment in tillage. So, if we’re going to fit tillage in during a three/four-year sequence, the most important time to do it is ahead of the corn. 

But back to the beans, which are the crops where we have had the most experience and success, the key is just to grow a really strong stand of cover crop, where the dominant cover crop should be cereal rye or another small grain. But what we’re moving towards is mixtures, where we still have rye in there or triticale, but then we also might have crimson clover or a winter pea. And the goal is now not just how to successfully grow the no-till beans, but how to make the no-till beans be a good foundation for the following crop. Right now, I’m thinking the best following crop should probably be corn, especially if I can grow a legume with the cereal rye. Then the following crop, if it’s corn, can really benefit from that legume. If I follow the no-till beans with a small grain like wheat or oats the next spring, the challenge is that we often do have some volunteer rye, and the volunteer rye can be really problematic in your small grain crop. So, to avoid that problem, we try to go into a warm-season crop, and the main warm-season crop that we have other than soybeans would be corn. Sunflowers are also an option, so you could possibly follow with sunflowers, but what we’re trying to figure out right now is how to create a sequence where no-till soybeans precede a good corn crop that includes some tillage.


What You Need to Know about Weed Control


TOM: All right. Well, Joel, I appreciate you taking the time to talk with us today about weed control and row crops in the Midwest. I think it’s something that a lot of people struggle with, and it’s just interesting to hear all the aspects that organic farmers need to think about. And if you had two minutes with a farmer, captive time — let’s say maybe they went through the transition part, and they were really just starting on their organic crops — you had two minutes with them. What would you really want to convey to them in that two minutes about weed control?

JOEL: First thing would be find out who is doing it well in your general area. You can look up on the USDA National Organic Program website every organic farm, and you can just identify all the organic farms in your county or in your cluster of counties and find out what they’re doing and whether they’re doing it well. And if they are doing weed control well, they are above average because there are many organic farmers that don’t do weed control well. But find the ones that are doing it well and learn from them. So that’s the first thing. I would say blind cultivation is underappreciated. Many people think it has got to happen with row cultivation. Blind cultivation is more important. You kill more weeds more quickly with less effort. Then, with row cultivation, it’s the first pass with the row cultivator that really matters. That’s what you want to focus on, doing the first pass really well. In terms of no-till systems, the most important thing is to establish a really good stand of cover crop. So you have to think about what is needed to do that, and for us, it’s not following corn. Well, we harvest corn late, and then we have all these corn stalks that are just difficult to establish a really good stand of cereal rye or a mix. We try to follow other crops like following a small grain. Then I guess I would say, just to come full circle, the most important resource is other organic farmers that are doing it well. 

There are also lots of written resources. There’s a new SARE publication called Manage Weeds On Your Farm: A Guide to Ecological Strategies. It just came out last year — over 400 pages — and it’s a unique compilation. It’s just information that I think is better than anything else that’s been assembled so far, and then there are tons of videos online. You were mentioning that you had watched a video shortly before this conversation. There are lots of good videos. There are good conferences that you can physically go to, but if you don’t make it to the OGRAIN Conference or the MOSES Conference, you can make it to these videos any time that works for you. And the winter time is a great time to watch videos and get up to speed on what your options are before. The biggest challenge is once the season starts, it’s relentless, and you have to do everything as timely as you can. So that’s not the time to be watching videos. But watch the videos in the winter, listen to podcasts like this one and take all those ideas that come to you. Get started on them before the marathon of the actual production season begins. 

TOM: All right. Thanks, Joel. Thanks very much for being a part of the podcast today. I know that you go around and speak, and for those people that might be at the MOSES Conference coming up, I know that you’re going to talk about weed control there. So thanks for all of your expertise and your time, and maybe we’ll have you again in the future.

JOEL: Sounds good. Thank you, Tom.

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