Bowel Mining

The process of taking one’s own manure and transforming it biologically into something that will nourish and support the earth, sequester carbon and provide food for countless organisms in a complex food web should be called bowel mining; the only form of mining where the earth gets something from us instead of the other way around. Alternatively you could say it’s just dealing with our own shit…metaphorically and practically. I applaud all the compost toilet owners of the world for doing their bit for the planet. The unsung heroes though, are the millions of strange and wonderful organisms that chomp through our manure turning it into beautiful rich soil. To get this process right and make the best compost has always been a goal I have aspired to and I have a few helpful observations that will improve your compost toilets function. Firstly it is important to point out that batch and continuous compost toilets work on very different composting processes. A batch system such as a Nature Loo or Farralones can get warm enough inside the heap to begin a thermophilic composting process, where certain types of bacteria called thermophiles grow rapidly in number and eat all the manure. Temperatures get up to 70 deg., killing off most pathogens (with the exception of parasite eggs or Oocytes). In comparison, a continuous style system such as a ClivusMultrum or Thunderloo work on a longer, slower breakdown process called mouldering. Fungal spores inhabit the pile and macroinvertebrates (bugs like slaters or roaches) slowly eat their way through everything left behind by the fungi. The type of bulking agent used in this last type of loo can determine the effectiveness of the fungal breakdown process. From my experience pine shavings tend to be less susceptible to breakdown from our native white rot fungi than they are to brown rot fungi found in cool temperate pine forests. So if you have a continuous style loo it might be well worth finding a source of hardwood shavings or sawdust rather than using pine. Alternatively a deciduous tree might provide a years’ worth of bulking agent with a rake and a wheelbarrow. In the lower reaches of your loo it can get a bit damp and this is ideal territory for the humble Surinam cockroach. I have been trialling these little critters for a while now and they are just fantastic at converting everything down to a very fine rich compost. Don’t fret, they don’t like light and prefer it damp so they won’t venture up the chute towards your bits, but they will eat and multiply, breathing in O2 and out CO2 so a lot of carbon just gets lost to the air. In this way the pile shrinks and shrinks, and emptying the loo becomes something you have to do a lot less often. If you have chooks, just let them free range in the loo for a while to give them a great feed of roaches before you empty it.


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