 This is Think Tech Hawaii, Community Matters here. You've joined me on likable science. I'm your host, Ethan Allen, here on Think Tech Hawaii. Thanks for joining us today. And what is more likable than food? All of us love food, right? And today, joining me by Skype is Dr. Joseph DeFrank. Hi, Joe. Hi, Ethan. How's it going? It's always a pleasure to be back with you on likable science. Great. Great to have you on board again here. So Joe DeFrank is a plant scientist, tropical plant and soil science group at UH Manawa. He's got a doctorate from Michigan State a bit ago. And he works on all kinds of things related to weed control, but not in the traditional way that a lot of people now think of it as weed control with chemicals and pesticides. Joe is really very interested in sort of appropriate, non-pesticide, non-chemical, sort of low-tech ways that we can control weeds and keep the soil intact. We don't have to tilt it up and all that kind of stuff that takes energy, time. So why don't you tell us a little bit about, sort of, go back in the history of agriculture as it were, Joe, to give us a little context. Great, Ethan. Well, what we're going to talk about today is no-till farming for organic farmers as well as home gardeners. No-till farming came into prominence in the American agriculture sometime around 1973, about the time when we had what was called the Arab oil embargo, where farmers needed to reduce their energy consumption with gasoline. And one of the ways they did that was try to reduce the plowing of the fields in preparation for seeding. Yes, that's what you mean by no-till, right? No-till, yes. Not plowing. So we don't want to plow. So generally what you would do is you would have like a crop of winter wheat, for example, and instead of plowing down the remaining stubble of the wheat in the spring of the year, they would spray it to kill whatever weeds were there, and then they would use specialized planters to plant seeds directly into that stubble. So you would have a nice mulch to retain moisture, prevent soil erosion, and of course you save maybe four or five trips across the field by not plowing. So I was interested in that in the early 70s at Michigan State, and then all these years I've been trying to figure out a way we could adapt that system for organic farmers. Right, because for organic farmers, of course, they don't want to spray the chemicals on the previous cover crop, and they can't do that and call it organic anymore. So what was your assumption? Correct. For organic farmers, of course, they can't spray herbicides to kill off weeds, and the only way they can terminate a cover crop, cover crop is going to be a plant that you're not going to eat, you're not going to consume. It's there to enrich the soil, increase aeration, and also serve as a break for certain pests. So once you have this vigorous cover crop on the soil surface, organic farmers were restricted to using the plow or disc to invert the soil, bury that organic matter, and then have a clean surface in which to plant in. Of course, that takes a lot of energy. It has a pretty big carbon footprint with the tractors moving and so forth. So what we were wanting to do is to develop a system where using something other than the plow and the tractor to terminate the cover crop, we're using light exclusion. Light exclusion through the use of these durable woven plastic fabrics is what we've been experimenting with. Right. Plants, as everyone knows, need light to grow, right? And if you really cover your plant over well and keep it dark, the green plants don't get the light, they don't manufacture their own food, they up and die. Right. So there's nothing new there. Plants need light. They don't get light, they die. So let me just go briefly through what we're talking about in terms of a technique for commercial farmers as well as home gardeners. I think it really shines for homeowners who may not be too crazy about taking a shovel to the ground and flipping it over. So the way this works is that you need to establish a cover crop for whatever reason. Like I said, organic matter, add nitrogen through legumes and allow that thing to grow vigorously to the point where you want to plant your cash crop. At that point, what conventional organic farmers are doing is doing what's called crimping or rolling. Right. So, hang on, there we go, all right, we got the pictures up now, all right. So this is your first picture here. Okay, so the first picture is actually our student gardens in the weed science class this fall at UH Manoa. And what you're looking at is a five species cover crop, meaning that there's five different seeds that were planted to give you this diverse, nice green, luscious cover crop. And the composition there that you're looking at is cowpeas, forage radish, black mustard, oats, and buckwheat. So we have a diverse group of cover crops so that we can address any sort of pests that may be adapted to one of them. We know we'll have something there that'll grow well. And the cowpea, of course, is a legume that's going to pull nitrogen from the air and add it to the soil. Excellent. That would be the first picture. Right. And the next, here we go, there's somebody rolling. Okay, so the next picture, you see a student there using a roller to crush down the cover crop. Farmers would be using a tractor-based roller and maybe not a smooth roller, but one with crimpers, you know, these raised edges that break the stem. So what organic farmers try to do is terminate the cover crop by, you know, crushing the stems and then they plant their crop in there. And the only problem is, is that you may not completely kill the cover crop. There may be weeds underneath that emerge once you mash it down. So I believe the next, after you do the rolling, the next picture would be illustrating the weed mats or the durable polypropylene fabrics that are available at most stores that sell commercial supplies to nursery men and so forth. Right. So would these down on their edges with some sort of little sandbags or water tubes or something? So what we're using for securing that plastic to the ground is what everybody who's familiar with tent fumigation in Hawaii, whenever they fumigate your house, they usually use water-filled hoses to secure the plastic to the ground so it doesn't come up. So that's what we're using. We get these used fire hoses, fill them with water, or we even have some hoses filled with sand that's shorter lengths. And that way we can cover the ground and then secure the fabric in windy areas with water-filled hoses. So it's a convenient way to hold it in place without poking holes and without having a bunch of rocks and stones to lug around and then take off when we want to remove it. Yeah, I know. It's beautiful and then it makes a nice solid, light-tight cover. And when you remove it then, it's the next photo I think we'll show. Yeah. Now when you remove it, what you're looking at there is a one week of coverage. So what we did is we rolled that cover crop and we covered it for one week and you might not think that one week of coverage is enough to disable that cover crop, but it is because it's hot, dark. And so now that the cover crop is killed, we haven't done any additional work, we haven't used any chemicals. Now we're ready to plant. So I believe in the next image, we'll see that the corn transplants have been planted, if that's up. Yep. And then you can see that the corn is growing normally. So I'd say, well, what's remarkable about all this? Well, what's remarkable is that number one, we haven't plowed the ground. That soil has been laying unplowed for well over a year. And so it's relatively firm. But what we do is we poke a hole in the ground. We put in corn transplants because we want to give the corn a big jump on any weeds that might grow. And we just poke a hole in the ground, stick in the corn transplants, cover it back up, keep irrigating. And then nutrients are released from that dead and dying cover crop. And voila, we have no-till farming for organic farmers. Yeah, beautiful. And in that one week, of course, not only does the existing plants that were there, they're all starting to die and decay. But then any weeds seeds or anything probably start to sprout. But without light, they're not going to do anything, right? That's correct. So generally, whenever you plant a cover crop like that, not only are you getting the cover crop, you're going to get certain weeds that grow, and they may be suppressed by the biggest cover crop. But once that canopy is removed, those weeds will just sprout up. That's the advantage of combining rolling and crimping with covering so that we kill the cover crop and we kill whatever weeds may be in the understory of the cover crop. Exactly, yeah. That's beautiful. Nice, wonderful how you put these seemingly simple little bits and pieces, the idea of a roller to crush the cover crop down, the idea of a light tight cover over the ground, it's a relatively simple concept. Nothing really high tech, nothing that had to be mixed up in a chemical lab, nothing that involves some fancy machines, right? Right. So yeah, it's all relatively straightforward when you say, well, yeah, I guess you just cover it up and then everything dies and you pull it off and then you plant. Makes a lot of sense. The challenge is how large a scale can we do that? You can imagine if you have a plastic that's 300 feet long and 12 feet wide, that could be pretty challenging laying it out in the field and then securing it. So the question is not every crop would be adapted to this. I see that the majority of crops that would be adapted would be things like nallow greens or microgreens where you can more or less seed it in a complete block and then harvest things aren't in rows. You're just growing as a complete block. And in that way, these organic farmers who are getting a premium for their products will have incentive to try to do this. Of course, there's expense to the plastic, but as opposed to plowing and tractors and if it rains, you can't get in the field. It gives, I think, farmers a lot more flexibility in timing when they pull off that fabric. They might want to wait until they may have a bunch of these fabrics out there. They pull one off, plant, let that get started, pull the next one off and plant and they don't have to worry about weeds growing while they're timing the plantings of their crops. So I just think it adds a lot of flexibility for commercial farmers and for the homeowner, it's great too because you may have a piece of ground that's a weedy mess and you go, yeah, I like to start gardening, Dr. D, how do I do it? I say, well, go out and get a sheet of plastic which you can get at various hardware stores. Now this is a plastic that's woven. It's not a film. So it allows irrigation water to go through it. So we just knock down the weeds, cover them, moisten the soil over the top with irrigation and then when you're ready to plant, pull it off, put a hole in the ground and plant some transplants and see what you get. Of course you gotta fertilize, but you're not plowing the ground so you're not gonna get a whole bunch of weeds. And if you mulch, if you add mulch in addition to your transplants, you might be able to get away with a prop without any weeding whatsoever. And then when you're done with the field, cover it back up and when you're ready to grow again, pull it off and plant again. Yeah, it seems like it's got a lot going for it and it makes a lot of sense. It would seem like it's economical to a good extent. The fabric I assume to be used at least several times, certainly, right? Oh yes, the fabric is very durable and I would expect that a farmer would get, I don't know, maybe five years of use from a piece of fabric and then I think they would get, if they worked it out where they had their crops on a regular basis, I think they could actually make money on it. And the reason why I throw this out for farmers to think about is because the farmers are gonna innovate on how are they gonna use it? How are they gonna time their plantings? And of course, picking it up and rolling it when it's a big sheet of plastic, that's gonna take a couple of people. So that's where you need to, but if you, more than one person, pulling it off, rolling it up and getting it ready for the next usage. So there's some innovation that the farmers will need to come up with to really make this an efficient practice. Sure, like almost any technology, you need to adapt a bit to it. You need to think of some new ways to sort of support it and apply it. But you've given people really a really nice set of tools to use, a really interesting approach that should be really applicable. And as you say, for sort of moderate scale organic farms for things like the mixed greens and salad mix kind of stuff that should be really a really sort of perfect thing. Yeah, I think a farmer can get two or three people out there. They could do a number of these patches at once. They can wait until they see the, there's rains on their way so they won't have to irrigate as much too. As the timing whole issue is really great. A lot of advantages to this, I can see. Yeah, and one of the bigger advantages is in Hawaii, we always think that it's always a great growing season year round, but we do have a rainy cycles. And one of the big problems is that for organic farmers is we control. You ask any organic farmer, one of the biggest challenges for production is we control. So let's say you get into a rainy spell, November, December, it's raining every other day. You can't go out in the field and control those weeds with mowing and plowing because it's too wet. You're just stuck there watching the weeds grow and watching them put out seeds. But the ground is covered with this fabric, there's no worries. The weeds aren't gonna grow. As a matter of fact, adding moisture once the fabric is there is causing weeds that are in the soil to germinate, thinking that they're gonna reach the surface, but they're underneath the plastic. So what you're actually doing is purging weed seeds from the production cycle. So it's an actual way to store the soil, get a bunch of weeds to germinate. And the farmer, it could be the wettest day of the year when he wants to peel off that plastic plant. So like I said, for moderate-sized farmers or for large home gardeners, I think it's a real simple innovation, makes sense to the average person. They're going, yeah, why did somebody think of that before? I said the same thing. I go, well, I wonder if anybody's gonna think that this is a realistic thing. And then I started doing my laboratories with the students and they just seem to accept it as, yeah, okay, that's okay, that's fine, that looks good. Great, we're gonna dig into this in more depth here when we come back, but right now we have to take a quick break here. We'll be right back. Joe DeFranc is with me here. I'm your host, Ethan Allen, here on Legible Science and we'll be back in a minute. I just walked by and I said, what's happening, guys? They told me they were making music. So I did. Aloha, my name is Mark Shklav. I am the host of Think Tech Hawaii's Law Across the Sea. Law Across the Sea comes on every other Monday at 11 a.m. Please join us. I like to bring in guests that talk about all types of things that come across the sea to Hawaii. Not just law, love, people, ideas, history. Please join us for Law Across the Sea, Aloha. And you're back here on Legible Science. I'm your host, Ethan Allen, here on Think Tech Hawaii. With me today via Skype is Dr. Joseph DeFranc. Welcome again, Joe. Ethan, good to be back again. Yes, indeed. And we're talking about some innovations that Joe has developed, really a very interesting sort of low-tech but very effective ways to help gardeners, small-scale farmers, avoid the need to till their soil, to turn over their soil, to have the heavy equipment to run their tractors. His approach by essentially crushing a cover crop and then covering it for as little as a week really opens up some great opportunities. And one of the nice things I was thinking a little bit over the break field was, you can leave that cover then in place, right? Sort of as long as you want. You say a week, but it doesn't hurt if it stays on for two weeks, three weeks or whatever, right? Right, we've had it going as long as eight, nine months over the summer, just waiting for the class to start. We pull it off and we're ready to go. So a great way to store the soil, essentially store that soil in a ready condition for planting with little to no effort. It's just there, ready to go. Yeah, and it's not eroding. You're not getting new weed growth. It's not blowing away. It's not packing down. It's just, as you say, it's sort of sitting there waiting. Yeah, so it's a good way to store the soil in the go mode for planting. Yeah, so I mean, if you look in that soil, just this is really my curiosity. If you look in that soil, you find the same kinds of invertebrate populations, earthworms and various little bugs all, those sort of sitting there doing their little business, right? Right, and what we found is that, if we leave that cover on for, if we cover, if we put the plastic over the top of weeds or other cover crops, what happens is that we have a real explosion of soil insects that consume that organic matter because they're not being preyed on by birds. So you have an accelerated breakdown of the organic matter and a mineralization of those nutrients back to the soil. So all around it's a pretty interesting approach and it also gives us an opening for a pest management. There's a thing called nematodes in the soil. Nematodes are microscopic worms that will penetrate the roots and ruin them. And for organic farmers, it's very difficult to get rid of those microscopic worms, but we've developed a way to combine a cover crop with the plastic to accelerate the removal of these microscopic pests. And the way that works is a little counterintuitive. You know, you think that, well, if I got this soil-borne worm that's eating my roots, I gotta plant things that aren't susceptible to it. But the counterintuitive idea is to know, we're gonna plant something that's super sensitive because these nematodes respond to root exudates of susceptible plants and just like a seed, those nematodes germinate from eggs. So once they perceive the roots growing, they germinate and they try to attach to the plant. But if we know the life cycle of those nematodes, we can then roll that fabric before they start to reproduce, cover it up with plastic, the plants dies, the nematode dies. Now we have a non-chemical way to get rid of this very persistent and challenging soil pest, nematodes, and use the same technique only with a slight little variation where we plant a susceptible crop, makes the nematodes come to life, they try to attach to the roots and before they can reproduce, we kill off the plant with this covering, the nematodes die, we pull it off and then we plant our susceptible crop. It's also giving us a new approach to pest management that I don't think we've thought about it in that way. Ah, I like that, it's sort of a little fake out, a little faint as it were, where you draw them out by planting something they really like when they all sort of go for that, then you zap them basically, you cover it over and they can't, they don't get a second chance basically. Right, no, I didn't think that up. Years ago, we had a scientist from North Carolina State, Don Schmidt, and he was a guy who was always testing chemicals for nematocontrol and soybeans. He goes, you know, Joe, the best year that I had was when we had an early spring in North Carolina, we planted the soybeans, I put out all my treatments, but then we had an early frost and all the soybeans died. When we reestablished the experiments and we grew the soybeans again, we couldn't tell untreated fields from treated fields because of just what I said, the nematodes all came into the soybeans, the frost killed them, they died, and so it's the same concept, it's sort of like a bait and switch. You bait them to your roots and then you switch them by turning off the lights. That's beautiful, that's beautiful. And it looks to me like this has a lot of interesting options to go new places, right? I mean, you're using right now one kind of fabric, but you could conceivably think about that fabric in different ways, right? Right, now I was thinking like, how can we make this better? You know, the fabric is kind of heavy, and when you get large sheets of it, you know, it gets to be kind of cumbersome to pick it up and put it away. And one of the things that happens when we use the fabric, of course, we can kill a living plant, but sometimes there's weed seeds that need light to germinate and grow. So what happens then is that we got to, we got to stimulate those weed seeds to grow, cover it, kill them off, and then uncover it. Now, with all the budding engineers and nanotech scientists out there, it occurred to me that, you know, we probably have the technology somewhere in our industrial base to do what I call nanoblankets or nanofabric. So what would that be? That would be like a super light fabric that, you know, with a certain electrical potential, it's translucent and let's light into the soil. So that would allow the weed seeds to grow underneath of the blanket. And then we add another little electrical potential and they reorient the molecules and then it turns it black. So then the weeds die. So this way we could start to purge weed seeds that are light sensitive to grow without pulling the fabric one and off. And then once the fabric is, all the weeds are dead, boom, you pull it off and move it to another field. So I think that there's probably, you know, engineers out there that maybe have this ready to go. Maybe it's ready for a, you know, they're using it as a blanket for a space shuttle to block light or to turn it on and off. But I don't think I've never heard of an agricultural use for such a thing, but I'm sure there might be some scientists out there that maybe they can let us know if they got something like that and we can work together on it. Yeah, sounds great. I mean, it actually reminds me of another one of my favorite technological advances, which is the thing called Matty Drops, which was a ceramic chemist, Jim Smith from the University of Virginia, had been working for years on pushing water through porous ceramics to help filter it and clean it up and adding silver into that to help kill off the microbes as it went through. And finally realized that he didn't actually need to push the water through it. He essentially put sawdust in with the clay and the silver nitrate baked it into kiln and then got a very porous ceramic. So water flowed by itself in through there and literally pulled off the silver and distributed the silver around the water, killing off all the microbes. Sort of again, it's a nice little low tech twist on a high tech idea. And I like what you're thinking about there. I think it has a lot of that potential. Great. Yeah, so that's kind of what I wanted to share with everybody today. And like I said, everybody thinks that we need to plow to get a soft soil for roots to grow. But really I like to say, let the worms do the plowing. We had enough organic matter and the plant roots when they die make channels and the worms come up and need the organic matter. So I say, let the worms do the plowing and we'll do the planting and the eating. Yeah, yeah. People don't appreciate how much work worms do. What is it they say over the course of a year, the worms in an acre of ground will turn over something like a ton of soil or something? There's some incredible figure I heard. I don't know. I'm sure it's incredible. And like I said, and see when you start plowing, then you're breaking up that earthworm habitat. You're killing them, you're breaking their channels. So a no-till farming was something that was, like I said, in the early 70s, it became popularized. But the organic farmer never really had a chance to use it because again, they can't use chemicals to kill off the weeds and kill off the cover crops. But I think with this technique, we can start to get them thinking about it and probably be developing some grants to expand it. And I've already presented this to some farmers in Hawaii and my understanding that they went out and got some fabrics and are gonna try it. So starting to break out of the idea phase and into the reality phase, so I'm pretty happy about it. Yeah, well, you should be very proud of it. And I could see great applicability of this technique too down in Micronesia, where people just really started and try to do some of this more push toward self-sustainability, developing vegetable crops and things like they can support a tourist industry, they can have more varieties of fresh food for themselves. And none of it's huge. A lot of it is this sort of farm, farm, small scale. Right, and tractors, equipment, fuel, it takes a lot of effort to take a field that's all weedy and maybe cover with grass and make it acceptable for crop production. But I think now we can just flatten it out to the point where we can cover it and it doesn't blow away. After a while, like I said, plants don't do too good when they're covering and once they die off, they break down pretty quick. And I'm pretty excited that it can really be something, things that it's something new that plants need light to grow. But I think the idea of the fabric, and if anybody can develop a new super light fabric, we could have some real exciting things happen. Yeah, exactly. This could go anywhere though, because again, you can ship that fabric out, rolls of it. That's not really the hard thing to do. It's not like shipping out a very complex piece of machinery. Hey, well, this is great, Joe. I've enjoyed talking with you here and I've learned a lot. I learned a lot the first time you were on and even more this time, pleased to see that you're continuing this and developing it in new directions. It's great. Thank you so much for sharing it with you and I hope all of our viewers will share this with their organic farmer friends. Ethan, it's always great talking to you and to the audience for likable science. All right, thank you, Joe. You take care. Thank you very much and have a good weekend. Yes, indeed. So that's about it for another episode of likable science here on Think Tech Hawaii. We'll see you next week.