biochar in Hugelkultur

I am looking for input on an idea that occurred to me on the drive home from work today. Sadly I live in a townhouse with a homeowners association, thus I cannot test this idea until my wife and I obtain our dream of a homestead of our own.

Given what I've read and heard in these forums, the wood in hugelculture beds will breakdown very quickly here in sub-tropic/tropic Southwest Florida. However the benefits of water retention and increased fertility will be realized much more quickly, due to this same process, though short lived.

Biochar supporters claim that the elemental carbon of biochar will remain and provide its benefits of water retention and nutrient banking for up to multiple thousands of years (I would be very happy with 100 years for my future grandchildren).

My idea is to combine the benefits of both by building a hugelculture bed with wood and biochar. In my head, the wood would break down as usual but the biochar would be there to catch and meter the nutrients over a much longer span. Perhaps this will minimize the water wash-out we expect here. Combined with the usual nitrogen fixing plantings and animal poop, we should be all set in that department.

I would love to hear from someone who has done this and not mentioned it yet. Also, if someone tries it wants to share we would all be so happy!

BTW: For anyone in Collier County, there is a free mulch pickup spot near the city dump. All you have to do is load it yourself. I think this would be a great way to obtain raw material for biochar. I wonder how fast the mulch would break down if that was the wood source...? things to think about.

I tried something along those lines for planting trees. I used my tractor to dig out a shallow hole and piled wood in it. I started them on fire and then smothered them with compost and dirt (really sand, i'm in central fl). I let them smolder for about a day and then soaked them.

I planted about 30 of the 40 holes a few weeks ago. The ones I let burn longer seemed better. There was lots on nice char and the wood that didn't burn was nice and punky. I did add a shovel full of compost when I planted the trees to give them little boost.

The holes looked great, but I'll let you know how the trees do. They're still alive so far!

Ben, thanks for the reply!

I am very interested to hear how they progress as time goes on. Do you have any control trees planted that you did not do this to? It would be interesting to see the difference.

What I would like to do is build Sepp Holtzer sized mounds with the addition of the biochar as a retention agent. Ideally a bed with no char, one with mostly char, and another with a mix would be great for comparison. I would like to see how long it takes for the wood to break down, how long it takes the biochar to charge and then begin providing nutrients, how long the biochar lasts, differences in plant growth and production, watering needs... ad nauseam.

I definitely should try a control. I'm hoping to reburn the 10 holes that I haven't planted yet. They were the first I did and don't look nearly as nice as the ones I burned longer.

When I plant those, I'll plant a few extras nearby as a control...it should be mostly mulberries, maybe some loquats and goumi.

This way of doing it was quick and dirty, I think your plan would be the deluxe version and probably more effective. Everything i've read leads me to believe that it should be a great combo! We'll see how it goes...

I would advise anyone attempting hugelkultur in the tropics and subtropics to beware of termites. Determine, if you can, whether termites in your area will attack living roots. I visited a place in southern India where the common practice was to put a dusting of DDT in every tree planting hole, because otherwise termites would destroy the main roots of the new tree and quickly kill it. It seems that burying wood that isn't already at least partly composted or charred might invite them.

Burning wood in a planting hole --- fascinating! Thanks for posting.

I'll have to try it, this fall when I plan to convert more of my vegetable beds to hugelkultur.

With heavy clay soil, this might be a good way to add permanent aeration material to the bed.

Will be interesting to see the result.


"Hugelchar"' is a nice moniker!

Eric Markov wrote:
"Hugelchar"' is a nice moniker!

Awesome! I wonder if I can change the heading from "Tropical biochar hugelculture hybrid" to "Hugelchar"?
Moderator?
Bueller?
Anyone?

C Hopper wrote:Sadly I live in a townhouse with a homeowners association, thus I cannot test this idea until my wife and I obtain our dream of a homestead of our own.

Why a homeowners association (I do not know what it is exactly...) prevents you from doing it?

Xisca Nicolas wrote: Why a homeowners association (I do not know what it is exactly...) prevents you from doing it?

https://en.wikipedia.org/wiki/Homeowners_association

Homeowners associatiations are much too complicated for me to explain but wikipedia usually gets pretty close to the mark. Sufficed to say that the rules prevent me from modifying the yard around my townhouse without approval from the association (all the other neighbors).

Now don't misunderstand, I do find interesting edible trees sprouting up all over the place... Must be those carrier pigeons from Sepp's place.

Also, the area of "yard" that I call mine is approximately 20ft by 10ft. See townhouse below. While mine is in a quiet gated neighborhood you can still get the point, I hope.

https://en.wikipedia.org/wiki/Townhouse


BTW, Thank you to whomever made the change to the thread title. Looks great!

C Hopper wrote:I have been brainstorming how to efficiently make biochar. The TLUD seems rather inefficient as so much fuel is burned to heat the retort.

I have not tried any of this yet as I just put it onto paper yesterday, but here goes.

construct an outdoor rocket mass heater with the following differences:
1. instead of (or perhaps on top of) the big bell (heat riser) that radiates heat, place an old iron woodstove (or any sort of sealable durable metal container) that would function as the retort.
2. There could be a wood gas exhaust line (from the retort) with multiple valves to allow distribution to mulitiple useful ends (internal combustion electrical generator, cookstove, down into the rocket...)
3. The insulating mass would cover the entire apparatus with moveable insulation for the retort door.
4. no long warming bench for the rocket exhaust. Place heat exchanger fins under the retort in the heat riser chamber, to extract as much heat from the exhaust as possible.

I am only imagining how this would work from listening to podcasts and reading articles. But with the technicalities worked out and much experimentation I think that it could be a much more efficient means of producing biochar and usable wood gas for the homestead.

Here are a couple childlike drawings that I made during an HR meeting at work, lol.

I wanted to add this to the discussion here.

I should add some note and explanation for the above file ^ I added.

The pdf is a scan of a hand drawn front view and side view of my idea. The proportions are probably not even close (especially the heat riser bell) but I think my scribbles get the point across. I would be very interested to hear ideas/opions from Erica &/or Ernie Wisner.

Wouldn't the entire bed need to be made of biochar? If it lasts that long, and wood deteriorates that quickly, you'd be left with nothing but char anyway. I imagine that would leave you with a small raised bed, which defeats the purpose of raising beds.

C Hopper wrote:Sufficed to say that the rules prevent me from modifying the yard around my townhouse without approval from the association (all the other neighbors).

Let's joke a little....
So, you have asked them in your head, and you have made their answer, and the answer is no!?

What you want to do is just some planting, and you want to raise the bed by introducing an organic safe product into the soil, are you sure they will not accept it? Or is your backyard not made of earth but of cement/cobblestones!

Xisca Nicolas wrote:

C Hopper wrote:Sufficed to say that the rules prevent me from modifying the yard around my townhouse without approval from the association (all the other neighbors).

Let's joke a little....
So, you have asked them in your head, and you have made their answer, and the answer is no!?

What you want to do is just some planting, and you want to raise the bed by introducing an organic safe product into the soil, are you sure they will not accept it? Or is your backyard not made of earth but of cement/cobblestones!

I don't think you understand how bad homeowners associations can be. Most of them will fight you having a "normal" garden, let alone having some crazy hippy hugelcultur thingy.

An association is not bad in itself, it is made of people...
They cannot be all the same.
And the person living there is also part of it!

What is a normal garden? Do you mean they ALL want only cement and no plant at all?

I was a homeowner as well, and been to some meetings.
I saw why some people were bad.
Owners are only persons who are very humans: they are afraid of other humans that they do not know,
and are afraid about not being quiet in their house.
So they prefer to kill the monster in its egg,
before they even know if what will go out will be a monster or not.
No risk.

Couple of thoughts:

I live in a neighborhood that doesn't have a home owners association but I still try to keep things somewhat nice looking for the conservative old lady that lives across the alley from me. I build up a hugel bed and then covered it with pine nuggets. It looks pretty good. another idea would be to invert the bed? Dig a big trench and then fill it up with stuff. If you cover it up with soil flush with ground level, nobody should be able to complain about it.

One thing about bio-char. Be sure you understand what you're doing before you make the leap. It doesn't break down. The char is going to alter the ph of your soil. My feeling is that this is good stuff, but that people are going to get too excited and use too much. Ease into it. When I'm doing research on it, I'm struck with the almost religiously zealous fervor around it. Not going to stop me from trying it out, but I'm not going to char my whole property willy nilly.