Learning about Biochar

A couple of Tuesdays ago, I gave a talk at the Merritt College Horticulture Department, in their Design Forum. The talk was centered around how to create an urban farm in a typical residential yard, as we have done here. It was a great night, filled with interesting questions from the audience, and as usual, I not only doled out some learnin’, I also received some learnin’. Every conversation I have with gardeners or farmers leaves me with new impressions and new knowledge, and then, of course, new questions.

One audience member asked me if I had any experience with biochar. The short answer was no. The slightly more detailed answer is that I’ve done some reading about it, and watched some educational videos from Living Web Farms about how to make it and apply it to your garden. I’ve also heard some negative things about it - that it’s a hoax - and I also have had some reservations about the way it is made; I have worried that the process of creating the biochar is actually releasing a lot of carbon into the atmosphere. The student who asked the question showed me some pictures from her own garden, of plants grown side by side, with and without biochar. Looking at those pictures, it was clear that there was a difference in the size, health, and production of the plants that grew WITH biochar. This intrigued me and I wanted to source some biochar of my own to try.

As my friend Lawrence likes to say, serendipity is everywhere, and that same night I happened to pick up a free copy of the fall edition of Edible East Bay magazine (which they make available in the Hort Dept), which I always enjoy and learn a lot from. And wouldn’t you know it, there inside was a huge article about biochar, and a story about a company that makes it in Berkeley (All Power Labs, more on them in a minute) and a community farm, Gill Tract, that has been trialing the biochar in their compost and raised beds systems. Well. I immediately contacted the lab and signed up for a year’s subscription of biochar. Today I went to pick up the first batch, and was absolutely blown away by the welcome I received from Aidin at All Power Labs, who then spent a good deal of time showing me around the joint and explaining the process of how biochar is made. He also welcomed me to the Local Carbon Network, which is a “community-powered local drawdown network.” I love this and I love that I’m a part of it, officially, though honestly I’ve been a part of it for years. :)

At the end of my visit, I mentioned Merritt and said that the Hort Dept should do some trials of their own with this product, and Aidin said, “What a coincidence, my coworker Austin is giving a presentation at noon at Merritt,” which turned out to be in my friend Lawrence’s permaculture class! I texted Lawrence and asked if I could drop in and hear the lecture and he kindly allowed me to do that, and I got to hear the details all over again (and take notes this time) which really helped cement the ideas in my brain. More serendipity!

So, here’s the scoop. All Power Labs was originally created to make renewable energy using biomass. That is, make power by burning the waste products of agriculture or even our urban yards - tree trimmings, wood chips, etc. In the process of making this renewable energy, a by-product was produced - bits of what looked like charcoal, very light and made of pure carbon. Originally they just threw this product out. Then they realized it was biochar, and high quality biochar at that, and that it was a coveted resource for farmers and gardeners, as it does a lot of cool things in the soil (which I will detail in a bit). The original purpose of the company, making renewable energy for use, was having trouble finding a niche in the very large solar and wind energy economy we have in California. So, they pivoted a little into the biochar side of things.

Shortly after that, they partnered with Gill Tract farms to do some trials and figure out how this stuff really works. Bob Flasher at the farm has been working closely with APL and seems to be quite sold on how the char performs in his garden and has documented how the plants perform. Knowing that he has been an early adopter of the char helps me to feel good about moving forward, trying it in my own yard.

Now more about the process. Above is a photo of the “Powermass Gasifier” which is the machine that turns biomass into both energy and biochar. The energy now is used to run the machine, so it’s a closed loop - no emissions or volatiles are escaping into the atmosphere. In fact, the carbon that is trapped in the biomass is turned into a product which can help sequester carbon into the soil. At this point, you might be saying, “Well, doesn’t compost do that too?” and the answer is yes, it does. It helps feed the microbiology which are turning the compost into humic acids in the soil, which do sequester carbon. There are some problems with compost, though, which you might have experienced (I know I have). One, it doesn’t last more than a season. I put a couple inches on my beds each fall, and by early summer, the beds look like they never had it. The soil surface is quite low, several inches below the top of the wooden beds. What happened to the compost? Well, some was turned into nutrients for the plants by the microbiology in the soil. Some, however, was off-gassed, releasing carbon into the air again as it decomposes further. Compost does continue to decompose, it doesn’t stop just because you’ve moved it to your veg beds.

walnut hulls, an abundant waste product from California orchards, which will be turned into biochar

Biochar doesn’t decompose. It’s already been processed into its permanent form - pure carbon. This happens in the process of Pyrolysis. The volatile carbon in the biomass is burned off (and used for energy), and what is left is like the embers of a campfire. Totally indestructible, permanent bits of carbon.

These bits of carbon, if applied to a garden/farming system, become hosts for a ton of microbial life. They absorb humic material. They have a very high CEC (cation-exchange capacity) which means that they add nutrient density to the soil. It improves drainage (tilth) while helping with water retention, as they can absorb many times their size in water. They improve friability of soil. They store the mineral nutrients from biological processes. They even, apparently, bind heavy metals and immobilize pollutants.

These are the composter tumblers that they are using at All Power Labs to do their own trials with biochar. And Aidin was clear that they recommend that we compost biochar first, not just add it directly to planting beds. There the biochar will be inoculated with the microbia of the compost pile and start to do work. There is a lot of evidence from Gill Tract Farm that adding biochar also increases the temperature of compost piles by quite a lot (this is something I desperately need). Not only that, Gill Tract has seen the temperature spike and then remain at high temperatures for six weeks after an application of biochar! I’m hoping to see this in my own compost piles. I came home with a large bucket of char, and added only a cup to the worm bin and about 10 cups to the large compost pile in the chicken run (they recommend adding 10% biochar by volume, an estimate is ok. My bucket should last three months). We’ll see how that works to activate heat and decomposition.

I also really appreciate that the biomass used to make this biochar is nut hulls from California orchards. This is taking something out of the waste stream, something that takes hundreds of years to decompose, and putting it to good use.

If you’re interested in your own subscription of biochar and live in the area, you can contact Aidin at The Local Carbon Network. It’s not cheap, I’ll warn you now, but I imagine that in time, when the benefits of biochar are documented and realized, the price will level out. I also believe it is worth it, if it will help me process enough compost to add two inches to all of my planting beds once a year. This would be terrific because I’m tired of buying compost, for many reasons: price (a lot more than this biochar), the unknown ingredients and their provenance, and the work/energy to get it here. So I’m invested in trying it to see if I can start to produce more compost here, in my yard.

To learn more about biochar, another good resource is the book Kiss the Ground , which is also, I believe, a movement that is part of the Marin Carbon Project.

The back of All Power Labs, which I just love. So Berkeley!

Have you tried making or using biochar? If so, I’d like to hear about it!

It Might Be Time to Plant Some Trees

Preparing for today’s blog, I went deep in to our photo history and, Lord, we have some beautiful pictures of trees. Tom and I have never been shy about taking pictures when hiking and it was really great, actually pretty comforting, to look through them. I’ll scatter some throughout this post. Most were taken in the last six years, and all in California.

I’ve been struggling with how to write about the climate issue. I suppose most of you have read the recent paper, put out by the U.N. Intergovernmental Panel on Climate Change. The headline in the Washington Post on October 7th spells it out in stark terms: “The World has just over a decade to get climate change under control, U.N. scientists say.”

I must say this headline, article, and the study it’s based on, has had me more than a little depressed of late. I don’t like to dwell on it, because thinking about what life might be like in ten years if we don’t make the necessary changes makes me feel quite hopeless.

But we must think about it, no matter how much we don’t want to. And I want to write about some things we can do - little things, to be sure - because taking action, no matter how small the action is, always makes me feel better no matter the situation, and maybe it does for you, too.

But on the other hand, I’m also very aware that some folks might feel defensive. I don’t want to shame anyone, ever. We all have our limitations. For some of us, they are economical. For others, it’s time. For still others, maybe there is a lack of urgency. But I don’t think we can afford, any longer, to remain apathetic about the issue.

I also don’t want to sound like I have all the answers, either, because I don’t. I’m paralyzed thinking about what my children’s lives will be like in ten years. I’ve been perseverating, really, about the problems; going over and over in my head about possible solutions, and what we can do to help the situation.

I feel our family already does pretty well with regards to conservation, but there are definitely things we can still work on. And I want to share our plan with you here, in the hopes that you are inspired to make your own plan, and maybe share it so we can learn from you, too.

The most important thing any of us can do is vote. Tom and I are looking for candidates and policies that continue to push environmental conservation forward, not backward. Adam, who isn’t even quite 17, has already pre-registered to vote when he turns 18. We discuss these issues during our family dinners and aren’t afraid to hash out differing opinions and wrestle with options. Our kids often have a perspective that we find valuable. I personally need to do better research about the issues on our local ballots. I’m good with national or state level issues, but not so ‘woke’ about the local stuff. This is my own personal goal for the next election. We wouldn’t dream of missing the opportunity to make our voices heard and voting is considered a mandatory event in our household. I hope it is in yours, too.

I believe we also need to take a hard look at ourselves and our lifestyle and figure out what we can do to make small changes. For instance, our family can eat less meat (conventional beef production is a major producer of greenhouse gases in the form of methane). What meat we do consume should come only from pastured animals (we’re pretty good at this already, but I’ve vowed to be even more of a stickler). Animals out on grass actually improve soil and do not contribute to global warming. It costs more, yes, and it’s not as readily available, both of which will help us to eat less of it.

Conventional dairy farms are also major contributors of greenhouse gases. We’ve made a pledge, in our family, to purchase milk, cream, and butter from Straus Family Creamery, a local company that is committed to reducing methane in the atmosphere. One way they do that is by reusing the methane as fuel for their delivery vehicles. All their milk and cream comes in reusable glass bottles (remember those?) and are returned to the store for a refund of $2. This makes their products more affordable. Also, all their dairy is organic. Their cows aren’t 100% grass-fed, but I do believe they are working towards that goal.

I really think it is worth considering big purchases too. One of our cars is electric, and I don’t think we will ever go back to owning a gas car in the future. Electric technology is imperfect to be sure, but California is making it easier and easier to own an electric car with charging stations everywhere, and even though they still use energy (some that comes from coal), there are zero emissions, so that helps in the long run.

Another thing we are planning to do this winter is put solar panels on our roof. We cannot afford to purchase them. But we can allow a company to put them on our roof, which feeds power into the grid, and we’ll get 30% off our bill. This is something I am researching now and will give you more details about it as I learn more.

Finally, we might all consider planting a tree or two. Trees are a major plus, sequestering quite a bit of carbon in their root systems and the soil around them. I once did a calculation to figure out the amount of carbon our Valley Oak (Quercus lobata) sequesters each year; 640 pounds. That’s incredible. There are a few guidelines however; not just any tree will do. You want to plant something native to your area, something slow-growing and long-lived. Check with your local extension office to determine which tree is best for your area (and if you live in CA, I can help you with that). A native tree will also benefit your local wildlife. Wildlife in general is going to have a hard time of it as our climate changes in the next few years.

If you can’t squeeze any more trees in the yard (Honestly, I am FULL UP), surely there is a local organization in your city that is planting trees in parks or open spaces. If not, there are organizations dedicated to restoring forests. Those organizations could probably use your donation to continue doing their good work.

I’m sure there are many more ideas that YOU have; please share them with us in the comments. Let’s learn together. Let’s have an open forum of ideas and suggestions. No shaming, just moving forward with solutions. Let’s take some action, together.

Determining the Amount of Carbon Sequestered by your Trees

This past semester, I took an Arboriculture class, and it was great - I learned SO much. As part of the class, we had to pick a tree we felt had some structural or health issues and write a report on it. It was a cumulative project; we had to know how to measure the health of the tree, how to do risk assessments, how to calculate value if the tree was to be replaced, etc., all of which sounds fairly simple but each step sort of builds on the one before. It was fascinating. I chose the valley oak in the photo above, for my project. 

The benefits of trees, particularly in an urban setting, are obvious and numerous: Trees save energy because they provide shade, they intercept stormwater and hold it on the property, they increase property value, and they provide benefits for local wildlife. There are many studies, both recent and ongoing, that show trees can improve the actual physical health of humans. They can intercept allergens and filter air, for instance, helping with breathing and air quality. Mental health and trees is also being studied. It's hard to quantify, but they can improve mental outlook and provide a very real sense of solidity and peace. Trees are also beautiful, a value hard to measure, but one we wouldn't want to live without. 

Another unseen way trees improve our environments is by sequestering CO2, which they use for making food through photosynthesis. Then they take those foods and store them deep in their root systems, in the soil. This kind of storage of carbon, or sequestration, is very important to the health of our planet. I won't go into the 'why' here, but if you're interested, see this article by the USGS, which explains it nicely.

It's rather interesting to take the trees on your property and determine how much carbon they are sequestering every year. There are several ways to do this. The industry standard is a tool called CUFR, which is provided by the US Forest Service.  They have an excel spreadsheet which will do this calculation for you. I had a little trouble with this interface, so I went searching for another way. I found another online calculator which is good if you have a common (not unusual) tree, called National Tree Benefit Calculator. You simply enter your zip code, then choose the kind of tree you have, and enter the diameter of the tree. 

***A word on diameter: This is a trunk measurement you take at breast height, about 4.5 feet up from the soil. It's called 'DBH' or 'diameter at breast height.' You'll see this in all the calculations; it's an important measurement and helps us to know the age of the tree. And remember (I needed a refresher course myself), diameter is the length across one side of the tree trunk; radius would be half that; circumference would be the length all the way around. (Hey you math people, stop giggling.) So for diameter, just take your tape measure or yardstick or ruler out to the tree and estimate about four and a half feet up from the soil, and then just put your ruler up to the trunk and see how wide it is. 

For those of you with multiple tree trunks at breast height, you'll need to do a different calculation (I'm thinking of your Coast Live Oak, Mom and Dad): please see this nifty explanation by the City of Portland. This also explains how to measure if your tree is on a slope.***

The Tree Calculator website is interesting, because it gives more data than just CO2. When you put in your info and it does the calculation, first you will see a pie chart overview; if you go to each tab above that, it will tell you more about each single factor. For instance, when I put in my oak tree, and I then hit the CO2 tab above the pie chart, it reminds me that "most car owners of an average car drive 12k miles generating about 11k pounds of CO2 every year." That's very helpful in context. According to them, my oak is sequestering 660 pounds of carbon per year, but I'm putting a much larger amount into the atmosphere by driving my car. I would need 20 oaks of this size to make up for the emissions from my car. 

So you start to see why trees can be very important even in unseen ways.

in full leaf, in September, a beautiful canopy

For my project, I wanted to actually DO my own calculation, so I found a research paper which explains how. For this calculation you will need to know the DBH and the approximate height of the tree, which can be difficult to estimate. I usually try to look at buildings near by, as one story is usually about 10 feet. I estimated my oak to be about 50 feet tall. 

Click on the box below to get a printable of how to do this calculation. It looks daunting but please don't let that dissuade you - I am the least mathematical person in the world and I was able to do it. It explains the 'why' of every step, but unless you really want to know that, you can just skip down to the bottom of each paragraph to learn how to do the next calculation.

With this process, I determined that my oak sequesters 488 pounds of carbon per year, a bit less than the online calculator said. I think this is because the physical calculation only takes into account the age and size of the tree, whereas the online calculator takes into account the type of species and where it grows, which is important for several reasons. Certain species sequester more carbon - generally trees that grow slower are the ones who store the most. (Side note - slow growing trees are also stronger and live longer.) Plus how the tree is adapted to your climate is important, hence the reason you put in your zip code for the online calculator. If the tree is native to your area, it's naturally going to grow better and store more carbon. For instance, you've already heard the details about my oak tree, which is native here and well-adapted to this climate. However I have a large southern magnolia on the property (Magnolia grandiflora) - it's not quite as large, but it is significantly older than the oak. When I put that tree into the online calculator, I find it's only storing 180 pounds of carbon per year. I would be willing to bet that a similarly sized magnolia in Georgia would be sequestering much more carbon than it is here in California. It's also interesting to see the difference between these two trees when looking at the other factors: the oak is intercepting and storing much more rainwater (very important here in our dry climate), it's doing a better job of cleaning my air, and it raises my property value quite a bit more than the magnolia. I didn't plant either one of these trees, but it sure helps me decide which one I'd rather have going into the future on this property.

This would be a fun exercise to do with kids, leading naturally into a conversation about how the trees on your property are improving it. It's also worthwhile to spend some time observing the tree and how the wild creatures use it (I spent so much time watching the songbirds in my oak that it made me realize what a value it is to them, not just to us). You can discuss how the tree increases habitat for many different creatures, providing food for some, shelter for others. You can discuss how the tree shades the house, decreasing the need for air conditioning. If the tree is native, you can read up on how the native peoples would have used it hundreds of years ago. You could take the leaves and make some art with them.  

But even if you don't have kids, it's worthwhile information to know and absorb. We often pay little mind to the trees on our property, unless there is a problem with them. This helps us appreciate what they are doing, in seen and unseen ways, to improve our immediate and greater environment, every day.