The new system sounds great – drop me an email sometime to let me know what all you are doing these days.

B

Here’s my best bet as to why your potato technique works so well: Wood is almost pure carbon, but it’s “tough” carbon, so it breaks down relatively slowly (therefore eats up nitrogen slowly), compared to other forms of C (e.g. straw, paper, etc, which are “softer”… read “Teaming with Microbes”, which goes further, into bacterially- and fungally- dominated soils). Sawdust has many times the surface area as wood chips, which will work the other direction — faster decomposition, faster nitrogen-eating. But it will still go slowly. I bet your sawdust is acting primarily as a sponge that retains moisture, and an aerated medium to provide your roots with oxygen. It will also add Organic Matter to your soil as it decays, which will still hold moisture, but also nutrients, and it will provide habitat for microbes, which are the ones doing all the work (they’re the ones the worms are after)!

The grass clippings would have a fair amount of extra nitrogen to feed your ‘taters, so it’s likely a great plan to have them between the plants and the shavings.

i wish i knew where to get a bunch of free wood chips! luckyyyyy…

bentley, i’ve got a new Worm Windrow that i’m building little-by-little using kitchen scraps, chicken poop and straw. The worms love it, and the chickens love me for it. When i peel back the tarp, they crowd around and gobble down any worm in sight. Not kidding, the worms themselves are what brought us together as friends.
Now that chicken poop is almost converted to worm poop to the point where i can turn it into plants! woowoowoo

JOEL – you’ve raised an interesting issue. I have a friend in Texas who uses vermi-trenches, but I can’t recall what (if anything) she has done to deal with fire ants – will need to touch base with her about that.
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TOFFEE – Your assumptions sound pretty good, although I would say it’s the vermicomposting process in general (not just worms) that provides the overall benefits. Also, while this can certainly benefit deeper roots, it can also really benefit the upper roots (this is where I’ve seen LOTS of evidence of roots growing right into the trench in fact)

How close you make the trench is up to you – it would probably just depend on the plants you are growing. I probably put my plants 1-2 ft away from the trench most of the time, although last year I actually planted some tomatoes right in the trench.

I recommend feeding the trench on a regular basis. With food wastes during the summer, you would likely need to provide a good feed at least once ever week or two in order to limit sinking and provide the worms with a good supply of food. With materials like manure you can probably get away with longer periods between feeding since the volume doesn’t get reduced nearly as much.

I don’t recommend adding a lot of worms initially – maybe start with a pound at the most. The last thing you want is to spend a lot of money only to discover that they don’t like the habitat. The best way to introduce them is by dumping in worm-rich material from another vermicomposting system – this way they have a protective safe zone to stay in if the trench is not providing the right sort of environment.

Rotten alfalfa is fantastic stuff AS LONG AS you can keep it nice and moist – you may want to mix in some absorbent material (shredded cardboard etc) as well. Just using straw and hay may result in a mix that dries too easily, which will lead the worms to venture off.
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PAT – Our summers generally don’t get that hot, so I can’t say for sure – but my suspicion is that you would be totally fine, as long as you have ample protective bedding over top. I have heavy clay soil myself, and have been amazed with the impact that my trenches (and other vermigardening methods) have had on my yard.

Thank you

Assumptions:
1. The trench is an inground lasagna bed with addition of purchased worms.
2. The trench with wet green stuff will not only feed the worms but also as a source of moisture for the targeted plants.
3. The trench needs to be relatively close to the planting area so the worms can move around the targeted planting area and for the plants’ root to reach the moisture.
4. The soil improvement of the planting area is done mostly by the worms and not the composting?
5. Since the trenches are relatively deep at 18-24″, it’s more efficient in helping the deeper roots since norm rototillers only tilt 6-8″?

Is my assumptions are right, then
1. How close must the trench to the planting area?
2. How often would the trench needs to be refilled?
3. How many worms per say 120 ft3 of trenches?
4. If lack of large amount of kitchen waste, can I use Alfalfa hay as green, straw as brown? What about shredder leafy branches of freshly cut hedges?

Thanks for helping.

Bentley–I suspect you have already heard of Growing Power, but if you haven’t, they’re a pretty neat organization. Their founder is working on sustainable agriculture and making fresh produce more available to inner-city kids/families. Vermicompost is central to his mission and he composts not only food waste but also brewery waste from some of Milwaukee’s smaller brewery’s. He’s also involved in aquaponics, as I know you are. http://www.growingpower.org/Index.htm