Ahh yes, those squigely little red worms are great bait. I keep an old garbage can in back of yard with holes drilled all over the sides & put all K. scrapps in it all yr. Dump it in garden in spring when I turn it over. Pick out worms & put them back in compost can. They get potato peels, coffee grounds, banana peels, old lettuce etc. all yr. till spring & I start over again. There's been times that it was STEAMING when I dumped it over LOL.

Large bags of sand-sized granular activated (merely means more porous) charcoal are available from the drinking-water treatment industry. So many people are phobic about their drinking water that this is now widely available. (The best source would be free used charcoal from a phobic neighbor.) I don't mean the small cartridges, I mean the bulk material for use in tub-sized canisters as large as swimming pool sand filters. The dry-cleaning industry uses fine-grained charcoal in its filters for dry-cleaning fluid. You never want to use this "used" but the new material would much more closely resemble the particle sizes in the "black soils."

Charcoal is made in cottage industry by building a fairly dense "teepee" style mound of wood (with a small opening in the center for starting, I believe), covering the entire mass with thick earth to hold in the heat and disallow complete combustion, and slowly burning (sometimes for days for a pile of logs as big as an SUV), using a small portal at the bottom of one side of the wall of dirt to control the amount of air entering. A lot of trouble. Instead, setting a normal open fire, burning it to glowing red coals, and then extinguishing with a water hose is probably the best home method. I do this with woody yard debris in the grill sometimes to burn out all the old grease. I extinguish it at the coal stage merely because I'm done with my main task. Lots of charcoal has incidentally entered my garden this way, just thrown out..

Bananas, wouldn't this charcoal method give you a variable combination of ash and charcoal?

I have some hardwood charcoal. I'm considering some experiments and would like some feedback on methods.

I don't have enough citrus seedlings to make the experiment meaningful. Is there a quick growing commonly available seed whose seedling has roughly has the same nutritional requirements as citrus? (I could get some seedlings...it is a citrus forum, after all.)

I was thinking of a comparison with Millet's mix.

Mix #1: 80% CHC
20% peat
Dolomite, STEM, Ferts (Millet's mix, off the top of my head!)

Mix #2: 40% CHC
40% Charcoal
20% peat
Dolomite, STEM, Ferts

Mix #3 40% CHC
40% Charcoal
20% rotted manure
Dolomite, STEM, Ferts (this mix based on the studies which show the bacterial component of terra preta to be important...the manure could serve as innoculant)

Maybe do some pour-through pH testing as well.

Watcha think? Valuable or a waste of time?

The ash easily shakes or washes off the chunks of charcoal.

Your test will be interesting and informative. But for a tight comparison and clues to causes of differences it is challenged especially in the comparison between 2 & 3 by the fertilizer and texture influence of the manure. If you want to test just the bacterial input or component, maybe make another batch of #3 but sterilize the manure going into it. Or instead of adding the manure into #3 make some manure slurry, let it settle and pour just the innoculated water into the mix. For an even tighter comparison, boil some more of the same innoculated water and add it to #2 to normalize the nutrient value. But even without these refinements it would be a useful experiment.

The other day I found a pair of seedling grapefruit plants at the Farmer's Market for $2. Perfect for my citrus charcoal experiment.

I planted one in the usual CHC mix. I prepared another with charcoal chipped to approximately 0.5-1.5cm pieces, in a mix of about 50% CHC, 30% charcoal, 20% peat, with a handful of compost as inoculant.

Weight post watering of CHC: 406g
Weight post wateriing of CHC/charcoal: 454g

Maybe I'll learn something, maybe not, but fun to experiment, anyway. I've got some charcoal mix left...any ideas for other experiments?

SB

Reading Millet's recent post on scoria got me searching here on biochar. I've been working biochar into a few of my garden beds for several years and have one bed that is 50% by volume biochar to about a 1.5 foot thickness. One thing that is very obvious in that bed is that drainage is incredible. When I leave a hose spraying on that bed I can't get it to puddle. Blending in something like scoria or expanded clay should give the soil better water retention without leading to water logging. This would act more like the Terra Preta soils that used char along with unglazed pottery chards. Seems like something citrus would like a lot. By the way, that bed grows veggies very well, but the first year they were about 10% stunted. Now all my biochar goes through my composter first to get it to equilibrate, or "charge" with nutrients so they aren't initially pulling from the soil.

Very interesting and informative !

Any updates yet ?

Hi,

I have tried charcoal as part of my soil-mix (10% volume). I used briquettes which I dissolved in water and dried them again. There was no problem using them instead of real charcoal. The plants do well (it is their second year in this mixture). For me the question is whether it is better to grain the charcoal very fine or let it coarse.
/Robert

As it was already said before, there is the problem of possible additives in briquets.

There is natural charcoal, even organic, so I think that would be the better choice.