241: The Biochar Handbook – How to Make it and Use it in Your Vineyard

For thousands of years, wildfires have produced a byproduct known to improve soil and plant health - biochar. Today, researchers like Kelpie Wilson of Wilson Biochar Associates, Consulting and Manufacturing are learning how to use this form of charcoal for carbon sequestration. Kelpie explains the different stages of combustion, what types of material to include in your burn pile, incorporating biochar into compost, how to use biochar to amend alkaline or acetic soils, and an easy way to remove vineyard wires from your pile.

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[00:00:00] Beth Vukmanic: For thousands of years, wildfires have produced a by-product known to improve soil and plant health. This is known as bio char. Welcome to sustainable. Winegrowing with the vineyard team where we bring you the latest in science and research for the wine industry. I'm Beth organic executive director. And since 1994 vineyard team has brought you the latest science-based practices, experts, growers, and wine industry tools through both in-field and online education, so that you can grow your business.

Please raise a glass with us as we cheers to 30 years. In today's podcast Craig Macmillan, critical resource manager at Niner wine estates with long time SIP certified vineyard and the first ever SIP certified winery. He speaks with Kelpie Wilson of Wilson, biochar associates consulting in manufacturing.

Kelpie explains the different stages of combustion.

What types of material to include in your burn pile? Incorporating bio char into compost. How to use bio char to amend alkaline or acidic soils and an easy way to remove vineyard wires from your pile.

If you love this topic, then you won't want to miss Josiah Hunt's presentation. Practical applications of pyrogenic, organic material, AKA biochar in vineyards. He shares his expertise at the sustainable ag expo taking place November 12th or 13th, 2024 in San Luis Obispo, California. joy, the perfect blend of in-person and online learning. Speak directly with national experts.

Earn over 20 hours of continuing education and explore sustainable ag vendors. As a listener to this show, you can take $50 off of your ticket when you use code podcast 24 at checkout. Get yours today@sustainableagexpo.org. Now let's listen in.

[00:02:00] Craig Macmillan: Our guest, today is Kelpie Wilson. She's the owner of Wilson Biochar Associates, consulting and manufacturing. And as you may have guessed today, we're going to talk about biochar. Welcome to the podcast, Kelpie.

[00:02:08] Kelpie Wilson: Thanks. Thanks for having me.

[00:02:11] Craig Macmillan: What exactly is biochar?

[00:02:13] Kelpie Wilson: Biochar is just charcoal, but it's special charcoal that, uh, you can use in soil or for purposes of carbon sequestration. That's the official definition from the International Biochar Initiative.

[00:02:27] Craig Macmillan: And what does biochar do for us in the vineyard?

[00:02:30] Kelpie Wilson: Well, it sequesters carbon, so it's a very stable form of carbon. Uh, Carbon comes in a lot of different forms. I mean, we're all made of carbon, and, you know, carbon can be a diamond, which is really stable, or it can be in a sugar, which, uh, you um, oxidized into CO2 pretty quickly. So uh, in is very, in a very stable form um, it's called aromatic carbon, so it's fused carbon rings.

which are the basis of all organic chemistry. biochar is. It's carbon. The thing about biochar and charcoal is that charcoal can have, you know, widely ranging different properties depending on how you make it and what it's made from. And I should add also that uh, in the definition of biochar, For use in soil or for use in carbon sequestration, it needs to be made from organic you know, that is clean.

So there are some environmental kind of limits around it that ensure that it's, it's really contributing to the carbon cycle in a positive way and that we're not making Materials that have, you know, toxics in them that could hurt soil.

[00:03:41] Craig Macmillan: So we're introducing carbon in a fairly stable people have told me that the carbon that you put into the soil in the form of biochar could be there for thousands of years, but it's obviously available somehow, or it's involved in the soil microbiome somehow, or it's involved in nutrient cycling somehow.

What are some of the properties that contribute to that soil health component,

[00:04:00] Kelpie Wilson: Well, There's there's quite a few. The interesting thing about biochar is that it's naturally present in soils in many, many parts of the world because of fire, from vegetation fires, forest fires, it's it's supposed to be there in many cases. Uh, Especially here in the, in the in the west coast where we uh, natural fire regime in the forest.

And if you look at the most productive soils in the world, for instance, the mollisols in Iowa or the um, in the Eurasian steppe, they have large amounts of biochar Um, In the case of the steppes and the plains, that's because of prairie fires. So you have these tall, tall grasses that would periodically burn off very regularly, like every 10 years or so, and the top would burn off in a flame, and that heat would radiate you know, kind of just above the root zone, the grasses are bunched up really thick, and some air is excluded, so they wouldn't burn all the way to ash, but the heat would turn it to char, the flame would move on, and you'd be left with char, and so this char builds up over years and centuries, and, you know, hundreds of centuries to make this a very black soil and then there are other places around the world historically going back thousands of years where it was deliberately to add to soil.

So those are the terra preta soils in the Amazon naturally normally didn't have a lot of fires. And look, also can look at charcoal middens around ancient villages and even city states where people would dump their manure and their, you know, their hue manure, their night soil, and they would always deodorize it with charcoal and ash, and you find very fertile black soils in those places.

So, it's not a new thing um, but we just kind of recently rediscovered So, as far as what it does in soil, you know, it doesn't break down. Like, you know, you asked, well, then how does it feed the It it sets the table. So It's the stable carbon with these fused carbon rings. It doesn't break down easily.

And we'll also have the mineral ash. from the vegetation that burned. And so that's food. And then it also needs the carbs and the protein. So, and that comes from all the fertilizer that you add to it. So it basically sets the table for soil life because microbes like to sit down when they

eat. And so you have all these little surfaces.

In the charcoal, it's very, very porous. You know, think of activated carbon. People know that activated carbon is used for filtration. It's got all these pores. And so, in that way, it's kind of like a sponge. It can hold air and soil, which is beneficial. But also, there's the surface area. So, each of those tiny pores has a surface around it.

And when you add up all the surface area, and this is kind of mind boggling, It's But you take a teaspoon of, of or, you know, that's got a lot of surface area or an activated carbon and it can have a football field's worth of surface area all inside It's, you know, it's, it's, it's amazing to think about, but all those surfaces are where the microbes can sit down and attach themselves.

And if we, if we have added fertilizer as well, there are nutrients and water. Attached to those surfaces by electrostatic attraction. So the microbes just can hang out there and, and it's all there for them. So that's how biochar promotes um, the soil food web by, uh, promoting the microbes. And then the their mycelia in there to, you know, get it's a foundation of good soil.

[00:07:42] Craig Macmillan: And you were talking about the fertilizer part. Is that one of the reasons why it's a good idea or a common practice to mix biochar with compost and spread it in that form?

[00:07:50] Kelpie Wilson: Yes, but I would not just mix it with compost if I have any choice at all. I would put it in the beginning of the composting That's where you're going to get the most benefit know, it just takes time for all these things to come And so If you start it from the beginning, not only do you get the nutrients and the biology in there right you're um, having um, beneficial impact on your composting So, You'll have fewer greenhouse gas uh, the compost will get hotter quicker uh, and you know, the char will absorb any kind of nasty stuff that's in there, reduce odors, etc. it's really, The thing about biochar and to make it really work for you in a, in a farm um, is to get every, Benefit you can out of it.

And there's a whole cascade of benefits that come with biochar.

[00:08:40] Craig Macmillan: we can talk about that some more, but let's get to some practical things. Let's say I'm interested in this. I've been hearing about it. I'm excited about it. I want to try this out. How can I make some high quality biochar with the least amount of emissions and the highest biochar production on my farm?

[00:08:57] Kelpie Wilson: Great So I've been working on this for quite a while. When I first heard about biochar, it was, I think, 2007, and it was the terra preta soils that we were all hearing about. I immediately got involved in it. I went to work for the International Biochar you know, was in close touch with people all around the world.

that we're trying to find ways to start making and using biochar, and a lot of the first people to actually do it were people who uh, you know, making little cook stoves or just making biochar in burn piles, and I saw that myself because I live in the woods here in Oregon, and I'd go out to where they did burn piles to, you know, We had a lot of extra vegetation that had to be thinned to protect from wildfire.

And I'd go to these burn piles and I'd find little chunks of charcoal left in them. And so we started making, doing experiments to see if we could optimize that. And we figured out make, take a burn pile and light it from the top. So it burned from the top down, and that would burn up a lot of the smoke so it was cleaner, and also leave us with a little pile of glowing coals at the end.

And anybody who's made a campfire has seen this. You have that pile of glowing coals, and if you just walk away and leave it, it'll all go to ash. But if you just simply put it out with water, hey, you've got biochar. So that's the way to start, and you can can do it in your a, with a kettle grill.

You know, just a little container that will improve the biochar recovery because if you cut off the air that comes in from and the sides of your you, you will just burn less of it to And again, you just put it out with water. So then I started making containers to improve the efficiency.

compared to making biochar in an open burn pile, if you put it in a container, You can make three or four times as much so, I've been working with little containers ever those, We call those flame cap kilns. Because the idea of how they work is you put your, make your burn pile in a container.

It's cutting off air from the bottom and the sides. So all the air comes from the And as it burns down, you keep adding more. And every time you add more material, it flames up. And the char that you've already formed on the bottom is protected from air by the container. And it's protected from air from the top because all the air that comes in is used in the flame of the currently burning material.

And so what you've already made is, is protected from oxygen. So you can build up a huge pile of char in a container, and you're only limited by the size of your container, really.

[00:11:34] Craig Macmillan: So the practice is put your feedstock in a container something that cuts off the bottom the sides from the air Light it from the top with kindling or something I would assume something lighter weight and then as that process goes and you can see the material come back Well, is it truly combustion if there's not a lot of oxygen?

[00:11:51] Kelpie Wilson: Well, uh, I call it combustus interruptus. So basically it is combustion, but combustion happens in stages. Okay. myths combustion. One is um, wood wood burns, wood does not burn. Wood gas burns in a And you can see this if you look at your charcoal grill, you see, there's not a flame.

Because the gas has already been mostly, you know, burned out of it. And so it just glows. So there's different stages of combustion. The first one is dehydration. When you heat a stick of um, water's going to come off of it, because water doesn't burn. And then the gases come out, and those are, methane, carbon burnable, burnable gases, and those make the flame.

And then when the flame goes out, you know, you just, that glowing coal stage. So it's, it's really staged combustion, and you're just interrupting and saving the char.

[00:12:49] Craig Macmillan: If I understand you correctly by putting more material on the top I'm continuing that process. The stuff on this top is heating up. You're getting that, flame cap. So you described it. And I can just keep layering on until my container's full. Basically.

[00:13:04] Kelpie Wilson: Yep, that's how we do

[00:13:06] Craig Macmillan: I want to come back to the kiln idea, but first, what are the, what are good feedstocks to make biochar from? What are feedstocks that are not good for making biochar? Right. Right.

[00:13:19] Kelpie Wilson: Good feedstocks are dry.

You don't want a lot of wet stuff, because you use a lot of energy burning the wet. , Good feedstocks are also appropriately sized. So grapevines, for instance, are good because they're not really big. Even the trunk of a vine is not really big. And so if you try to put a big log in your container on your fire, you use so much energy to get the heat into the center of the log.

So it's a progressive thing, right? You're charring the outside, and the heat's moving in, it's charring and charring and charring. But meanwhile, the outside of your char is starting to burn to ash. So it's not very efficient to try and char a big log. The kind of limit depends a lot on the fuel moisture.

In Utah, we're We have really dry wood. People are putting six and eight inch diameter logs in a kiln and doing fine. In Oregon, I kind of keep it to four inches, usually. But you know, we could do bigger stuff. It's just not quite as efficient. So dry less than 25 percent moisture is ideal. We can do wetter stuff, and we often do because we're here in the middle of winter trying to get burn piles taken care of. So we go ahead and do it, and there's some techniques for optimizing how you do that, how you load it. But dry, less than 25%. and not too big, but also not too small. I've really tried hard to biochar hemp stalks, for instance, which are abundant around here, and they're just a little too small.

if they're dry, they do pretty well, but you have to really make sure you don't pack them in too tightly because, small, small things like straw, and crop waste like that, they will pack and cut off the airflow and you'll get smoke.

[00:15:07] Craig Macmillan: Oh,

okay.

[00:15:08] Kelpie Wilson: That's the main issue is you get smoke.

And then as far as what species, the main difference between different species of wood, for instance, is density.

And because we're making biochar in a flame, we're making it at a very high temperature. So it's, as long as we're not smoldering it, As long as we have the flame present, we know we're making it at a high enough temperature to burn out most of the volatiles. Know, some species like eucalyptus or walnut might have chemicals in them that are allelopathic, I think is the term.

And if you add a lot of that to soil, you could have problems. But as long as we're making it at high temperature, we burn most of that out.

[00:15:50] Craig Macmillan: Got it. So we want things that are dry. We want things that are woody, that are relatively high in concentration. Things like grasses are probably not going to work as well or work terribly well. It sounds like you want chunks basically, you know, something about the size of your forearm or a little bit bigger chunk would be a really

great, size.

[00:16:09] Kelpie Wilson: that's a great way to look at it. I like the physical measurements. You know, I was telling woofers here the other day about how to, make biochar compost. And so we're doing it in layers. And I just said, think about Parmesan cheese. When you add the biochar, if you really like Parmesan on your pizza, just add the biochar like that.

So those kinds of physical measurements are really helpful for people when they're learning how to use biochar.

[00:16:33] Craig Macmillan: and returning to that topic you recommend putting biochar in your composting windrows at the beginning as part of the whole process.

[00:16:41] Kelpie Wilson: Yes.

The very beginning when I think about a vineyard, especially one where you're actually making the wine know, you're pressing the grapes and you have the is it called

pomace? I think the grape skins that's easily degradable stuff. It's hard to, compost just on its own because it doesn't have much carbon, but if you add biochar to that, you can make a beautiful compost.

And then great for reducing on farm inputs. contributing to the circular economy. And that's always how I recommend people use biochar if possible, is find whatever other organic waste streams are there, whether it's grass clippings, grape pomace, leaves, anything else, manure that you might have, mix it right in there.

[00:17:27] Craig Macmillan: Makes tons of sense. Okay. Let's get down to the nitty gritty here. We've touched on kilns as a way of getting the highest production. Tell me about the Ring of Fire Kiln system the concept in general. And then what might, what might be a biochar production day like?

[00:17:42] Kelpie Wilson: The Ring of Fire kiln is my latest, greatest design. Just bin kilns, but they were heavy. So They were, weighing a lot, and you had to, move them around, and very hard for one person. So I came up with this modular design of panels. And so you can hook them together.

They're four feet long and 40 inches tall, and they have a bracket that hooks them all together, and you can make a kiln any size you want. with that. I mean, not too big, but usually we make kilns that are between six feet and 12 feet in diameter. And so that can accommodate the piles you already have, for instance.

And then the other innovation with that kiln is it has a heat shield. And that's really important for two reasons. One is it holds more heat in the kiln so you get more production. It's more efficient. But the other one is that it protects the worker. Because when you are around a giant , flaming pile, you know, you can really get fried just from the radiant heat.

You know, you're not burning up, but you, the radiant heat, I would come away from some of my sessions with very red skin and very dehydrated. And so we really think a lot about the workers who are doing this. Because it's mostly hand labor, although we can also load the bigger kilns with, machinery. that's the Ring of Fire Kiln. It's also very, very clean, and there's a gap between the heat shield and the inner ring that allows, um, air to come through, and then so you have preheated air that's going in from the top into the kiln. And that also helps a lot with, uh, Reducing the smoke. And I have lots of pictures and videos showing the smoke being sucked into the kiln from the top.

It's really cool to see these loops of smoke kind of coming up and then being sucked back down into the kiln. Those are the advantages of the ring of fire kiln in addition to the fact that it's modular. One person can take it apart and move it one panel at a time. The panels only weigh less than 40 pounds and set it up somewhere else.

That's, that's the other advantage of the ring of fire kiln. So a typical workday, and I'm going to quote some numbers from my colleague Eric Meyer, who has Napa char, and he's done some incredible work in vineyards in the last couple years. Here's what he says He can make up to 12 cubic yards of biochar per kiln per day, which is two bone dry tons.

And that is equivalent to two to three acres of pulled mines. he'll do this usually with one helper. Sometimes he'll have a, a mini excavator that he uses to load it, but a lot of times he's just doing it, you know, as hand labor. And so that's a ;lot of biochar, two tons of biochar in one day. He'll start by arriving at the site, setting up his kiln, and then just hand loading the biochar initially, fill it full, light it on top.

There's a little break where you let it burn down till you start seeing glowing coals at the bottom and, some ash on the top. And then you just load it one layer at a time. And the loading rate is really critical. If you overload, you get smoke and you'll end up maybe even with unburned pieces in the bottom because the flame moves up in the kiln as you add more material and the bottom starts cooling off.

You don't want to leave any big pieces at the bottom. We load small pieces initially. And if you have bigger pieces, you would load them kind of toward the end or in the middle. And then when it's all full of biochar, or you're just done for the day because you're tired, you get some water out and you spray the kiln down with water just to cool it.

Then you open up the panels, and rake it out, and you spray it with water and rake it at the same time. So you end up with a big, big patch of biochar on the ground.

[00:21:29] Craig Macmillan: Perfect. Then you take that to your composting spot and away you go. .

[00:21:32] Kelpie Wilson: another piece about making biochar from vineyards, especially vineyard removals, is that a lot of times there's wire, trellis wire, in it. And you could have a big pile and you could build a kiln around the pile because you're not untangling that pile, right, with all the wire in it.

And then at the end, uh, you know, you pick the wire out of the char. You can use a magnet.

[00:21:52] Craig Macmillan: That's cool. What are some things that we should be concerned about not doing? If we are newbies to biochar production.

[00:22:00] Kelpie Wilson: Yeah, that's a really good question too. So, you need to know a little bit about your biochar. If you have a lot of ash in it, it can be alkaline. So if you have an alkaline soil, and you have alkaline biochar, you need to think about how you're going to apply it and maybe, usually composting will take care of any pH issue.

If you have an acidic soil, you might want to just add it directly. You know, take the most advantage you can get of that liming ability. You also don't want to add too much at one time, especially without composting it first, because it can, , lock up nutrients for a short time. Most likely you're not gonna have too much biochar for a, for a big field. Um, It's great to be able to do it a little bit every year. That's the best way to incorporate it.

[00:22:47] Craig Macmillan: Oh, and that's another question. I've seen different strategies here. Some folks believe that it has to be incorporated into the soil. Other folks say, no, that's good, but you can go ahead and spread it at the surface and you'll still get some benefits. Is that true?

[00:22:58] Kelpie Wilson: Well, it's going to depend a lot on what you're trying to grow. So the vineyard trials that I've seen using biochar, a lot of times they're putting it in at planting and they're putting it in deep in the root zone. That seems like a good idea to me. One thing I'll say is when I look at the literature, I read a lot of the biochar research literature.

There's some really interesting new material out about replant disease. So if you're replanting in a vineyard, you know, in an old vineyard, new vines. The soil can harbor pathogens that the older vines were able to resist, but the new vines have a hard time with. And biochar has a lot of benefits for disease resistance, just because it promotes a lot of microbial diversity, so you don't get the dominance with some of the pathogenic fungi and other organisms.

So, you know, adding it, deep You know, when you're doing the replanting, replacing a vineyard is probably the most beneficial way, to add biochar. But if you already have a vineyard and you're using cover cropping, for instance, it'll go really well with a legume cover crop like clover and you don't even need to compost it because clover and legumes fix their own nitrogen and And biochar is especially wonderful with legume crops because it promotes the nitrogen fixing bacteria. If I just had a couple bags of biochar and I wanted to use it right away, and I was, planting a cover crop, I'd just use it in the cover crop. I think vines are like any other plant, where they have roots that come up close to the surface, they can get benefit from surface applied biochar as well.

[00:24:39] Craig Macmillan: So if I'm following this idea, so from a cover cropping standpoint, what am I going to do is broadcast it and then plant my cover crop. That'd be one way of building the health of the whole floor, which is a really good idea. What about banding? It's very popular to band compost right into the vine row.

If I have compost that's got biochar in it, will I get those benefits as well?

[00:24:59] Kelpie Wilson: I would totally think so. The other thing about biochar is that it holds water. So, you know, in, droughty areas that would be helpful to,

[00:25:08] Craig Macmillan: If there was one thing, just one piece of advice that you had for folks, Who are interested in starting to produce biochar and use biochar. Let's talk about it one for production and one thing for use. What would that be? What would that two part advice be?

[00:25:25] Kelpie Wilson: first of all, uh, get one of my ring of fire biochar kilns. It's a, you know, it's really economic. And second of all, buy my book, the biochar handbook, because I have all kinds of information in there about composting, you know, different ways to culture biochar, build soil. Well, you know, so sorry to be so nakedly promotional there, but

[00:25:50] Craig Macmillan: Well, you know, you're directing, you're directing people towards resources,

[00:25:53] Kelpie Wilson: right.

[00:25:53] Craig Macmillan: Anything else?

[00:25:54] Kelpie Wilson: Oh, well, I'll send you some other resources, too, that you don't have to buy the book. Check out the U. S. Biotar Initiative website. There's a Biotar Learning Center there and USBI has collected a lot of resources there. fact sheets, their seminars, webinars. There is a lot of biochar information out there.

And I will say I've watched a few YouTube videos that are just. Make me cringe it is so easy to experiment with it yourself, which is great. It's really great that people experiment with it. And I think, feel free, you know, do your own experiments. , there's some not so great information out there that, you might want to just do your own work and look at the more authoritative sources like that the USBI before you take what a YouTuber says as, as gospel about biochar.

So I guess my one advice really on both, topics of production and application is just jump in and try it. It's so easy. You know, make it, make a bonfire in your backyard or, any kind of little container. You could dig a little shallow pit in the ground and, just make some biochar, then you've got some.

Now do some, greenhouse trials. You know, see how it interacts with your soil because every soil is different. And so, check the pH, add it to, you know, your soil, and, grow a seedling. it's very easy to do some experiments. I actually have, in my book, a whole procedure for how to do a, scientifically valid experiment. Uh, Pot trial in the greenhouse, so you can really, step by step, you can really look and see how it compares with other amendments, try it in your compost pile, use a compost thermometer, it's not straightforward how to use it in compost, because again, compost like soil, it's going to have a lot of different kinds of ingredients, biochar does really interesting things, in compost, so.

Just try it.

[00:27:46] Craig Macmillan: Just try it. Like that's great advice. Our guest today has been Kelpie Wilson. She's the owner of Wilson Biochar Associates Consulting and Manufacturing. Thank you so much for being on the podcast. This has been some really great practical, actionable information, which is what we like to bring our listeners.

As Kelpie mentioned, we're going to have a lot of links to things and resources and whatnot on the show notes. So be sure to travel to that page. I'm finding that this is a growing topic of interest, but I'm finding that there's more and more folks that are trying it, and we're all very excited for what the potential might be.

[00:28:17] Beth Vukmanic: Thank you for listening. Today's podcast was brought to you by San agro. WestBridge is now San aggro. When the opportunity came to expand their reach and improve their customer's bottom line, they took it. San Agros commitment to deliver science-based solutions for sustainable crop health and nutrition remains the same.

They offer a full line of plant nutrients, bio pesticides, and specialty inputs. Visit San agro.com to learn more.

Make sure you check out the show notes for links to Kelpie her new book, the bio char handbook, a practical guide to making and using bioactivated charcoal loads, more links to bio char plus sustainable Winegrowing podcast episodes. 56 conservation burning and bio char. 1 0 6, what? Barry charcoal and the vineyard. 1 67. Used bio char to combat climate change and two 15 bio char production on a commercial scale. If you'd liked the show, do us a big favor by sharing it with a friend. Subscribing and leaving us a review.

You can find all of the podcasts on vineyard team.org/podcast. And you can reach us@podcastatvineyardteam.org. Until next time, this is sustainable. Winegrowing with the vineyard team.

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