Sunday, November 23, 2008

Tales from the Bucket: Time!

The folks over at Wriggly Wigglers asked how long it takes people to achieve compost from cured bokashi. Before, I would have said about a month. Now...yeah, about a month in warm weather, bit more in cool.

I do have to mention that there is some insect activity here, for the most part of the unseen and untroubling variety, but that’s to be expected in any “cold” compost situation. There is no odor aside from the faint forest-after-rain scent that good soil exudes, the giant possum lumbers right past the buckets on its (his? her?) way to wherever, and the gnats the bucket sometimes develop after being rained on will go away as soon as the top layer is disturbed. Snails and geckos may be more of a problem, depending on your area and tolerance for same.

If you’ve read more than a single post here, you already know that I live in an apartment and have no ground in which to sink a bottomless bucket for the conversion of bokashi into compost. So I’ve been experimenting with bringing the soil to the bokashi, rather than the other way around. It’s not necessarily an ideal solution for me—my supplies of soil are limited, and I have things growing in most of it—but it works.

This takes equal parts cured bokashi and soil, and I tend to use soil that isn’t at its peak but will still support plant growth (because my better soil has plants in it). The reading I did before first trying this was...confusing, shall we say, with some writers insisting on a minimum of ten gallons of soil per bucket of bokashi—if you assume that’s a five-gallon bucket, then two to one—and others using numbers familiar to me from traditional aerobic composing, though I’d never before seen them in relation to bokashi fermentation: “At least a cubic metre of soil” That’s something like twenty gallons. For one bucket of bokashi!

Not only do I not have that much soil, I haven’t got that kind of space. (Yes, that’s only the size of a large trash can. Still.) The reason for that figure in trad composting is to generate and sustain the desired thermophilic reaction—so the pile will heat up, destroying weed seeds, diseases, and other undesirables.

Hot compost isn’t feasible in small volumes without some technological intervention. Tumblers and activators, say. But my first bokashi buckets were vegetarian, none of them contained any weed seeds or diseased matter, and I don’t have any objection to cold compost for the most part. So I decided to risk it and tried two-and-a-half gallons each of cured bokashi and soil. It took about a month that first time, with summer heat, though unfortunately I don’t have an exact number for that one or the two that followed it. The photo above is what I tipped out of my Wriggly-spurred time-test bucket, begun one month ago today. It’s not quite mature yet, and some of the leafy bits introduced with the old soil are still identifiable, but the bokashi’d kitchen waste has all been converted into plant-pleasing compost, conveniently mixed with the soil already. Call it a month in warm weather, five or six weeks in cooler.

To Make Compost in a Bucket

1. Select your bucket.

Not, mind, a bokashi bucket! This method uses a large planter. Many of mine are five-gallon buckets with holes drilled in the bottom and sometimes lower sides, but any large planter should work, as would a smallish barrel or what-have-you.

This time, I didn’t add any drainage materials to the bottom; sometimes I do. Not sure if that affects the time (I’ll try to remember to test that someday). Drain holes are required!

2. Acquire a volume of soil equal to the amount of cured bokashi.

Cured here being defined as

a. at least seven days after the last addition of fresh waste, and
b. no longer producing more than a few drops of bokashi juice daily.

3. Put an inch of soil in the planter.

If you have mixed-quality soil, the worst of it goes here. Fill dirt is fine; a soilless potting mix is not.

4. Add bokashi and soil, mixed or layered an inch at a time, until within four inches of the top of the planter.

This is what will compost, so you’re looking for healthy soil microbes. If you have better-quality, fresh-from-the-garden soil, it goes here, not in the bottom. Compost breaks down faster the smaller the pieces, so smushing/chopping large pickled bits might not be a bad idea. Adding a bit of mature compost, unsterilized, should produce an even richer mix, and could substitute for most (if not quite all) of the dirt here though not in the outer layers, although I can’t yet confirm this from personal experience. (Another test!) It should also be possible to use less soil for this middle section and still produce compost, so long as soil microbes are adequately distributed, but again, no personal experience hereabouts for that. Equal parts, I can attest to.

5. Top with three inches of soil*.

6. Cover loosely, but do not seal, and

7. Set the bucket someplace out of doors, out of direct sunlight, and out of the way for at least one month (more in cooler climes). Near an existing, healthy garden would be ideal, but on a wood patio or shaded cement parking space works.

This produces an amount of compost-amended soil not quite equal in volume to the original ingredients, though the reduction isn’t dramatic. But though this is a great way to refresh tired soil, it’s not ideal for me, requiring as it does that I divert relatively large quantities of soil from my immediate gardening. So I’m still playing.

Back to the buckets!


*Two inches of soil and two of dried leaves would probably work, but I haven’t tested that yet. Two inches of leaves or soil alone does not create enough of an odor barrier to keep the raccoons and possums from sniffing it out.

[Edited Dec 01 to correct typo and clarify a phrase.]

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