This is a blog of the 31 things we will be doing in the month of January 2010 as part of our sustainable communities group. This post explains it all.

Tuesday, March 23, 2010

Oh what a lovely tea party.

draw back the curtain.

The teabag is a little well-brewed.

The weeds have been decomposing anaerobically for a good month and a half now (just a few weeks longer than was recommended by Gardening Australia). The basic process of anaerobic decomposition is that the microorganisms break down biodegradable material in the absence of oxygen. This releases the energy into the water rather than the air. It's used a lot to treat waste water and reduce the release of gases and such from landfill. On an industrial scale anaerobic digestion can be a renewable energy source. Methane and carbon dioxide rich biogas can be harvested and burnt to drive a turbine. What we did was a little more lo-fi, not in an air tight vessel or set up to siphon off the gas, but none the less the same process. We are more interested in breaking down the nutrients in the biomass (the weeds) into a form that the plants can use easily. Unfortunately this works too well so the final mix needs to be mixed with more water to dilute it or it will burn the plants.

Black with one.

Anaerobic decomposition happens naturally in mangroves; their leaves break down in the oxygen starved mud; however in that instance the mud is high is salts and so they smell like sulphur (rotten eggs). The "beautiful, brown, sludge" that formed in our weed tea smells like death. The water is releasing many of the gases that have dissolved into it over the weeks.
There was also an abundance of invertebrate life gathered in the pot. Many small compost flies and about six spiders had taken up residence. To these bugs the rotting smells means food or food for their young.

We haven't put it onto the garden just yet. We are making some seeds for Autumn planting and I hope they like tea. The tea bag on the other hand had can go on the compost heap.

Lars comes in for a whiff...

... and feels a little overwhelmed.

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