brian Hughes

Edited to add: Just looking back, I've realised that due to a major senior moment, this post is pretty much a rehash of my previous post- a lot of the questions were asked and answered- thanks for the replies. The update is drilling the holes in the barrel, which will hopefully let roots and earthworms in, and effluent out, but keep burrowing rats out. I'd still welcome suggestions about what to plant in the vicinity.


I'm currently experimenting with composting solutions, but approaching them as a waste management solution, rather than a source of a product- I'm hoping that I can get greedy plant roots and earthworms to do the harvesting of the compost, and reduce the amount of intervention required. The immediate problem is that at the Off-Grid site where I hang out, food is abundant- the pickings are good for out of date supermarket food, but unfortunately there is a major rat problem, and I want to hit their food source. The setup so far is: a 200 litre barrel with 20mm holes drilled in the bottom buried about 300mm deep in woodchips. I've added perforated lengths of guttering round the inner surface, and a length of perforated 100mm drainage pipe in the middle to aerate the system, and put a heavy lid on top. I've chucked in a load of kitchen scraps, and so far, there seems to be a bit of heat, and volume reduction. The soil in the area is mostly clay, but with a long term project to mulch with woodchips.

Have I started on the right track, or the road to hell?

My questions are:

What should I/ shouldn't I add to the recipe? Remember, the primary objective is rat-proof food waste disposal- green waste can go into an open frame composter.
The abundant resources on site include: Tree surgeon woodchips- probably too slow to decompose, cardboard, straw, and pissoir charcoal. I'm especially anxious to get charcoal into the ground.

What should I plant in the vicinity- I'm looking for something with greedy roots that thrives well in the shade?

Do I need to add earthworms, or will they just turn up? What is their optimum depth? How do I create a heaven for earthworms, and a hell for rats?

Thanks for any replies.

Thanks for the additional replies- @Galadriel & Tyler- going down the chicken route can't happen as it would jeopardise funding from a vegan charity pot, and there are concerns that there isn't the critical mass of know-how to take proper care of the existing two pet chickens. I do like the idea of the worm towers, and they should be easy to implement with clippy top plastic barrels.

Thanks for the replies. There are two chickens on site, but I would, at this stage, be reluctant to push forward in this direction, due mainly to the input needed to ensure the chickens' welfare and quality of life. Is there potential in the liquid effluent which could be sucked from the bottom of the barrel, and used as an innoculant for biochar?

A bit of background- I hang out at an off-grid community which unfortunately has a major rat problem. I'm currently looking at solutions for food waste disposal (mostly vegetarian/vegan) that keeps waste decisively away from the rats. What has shown some promise is an in-vessel system based on a 205 litre barrel. I use guttering and 100mm waste water pipe to create ventilation channels down the cooler outside and up the warmer centre to maintain air circulation, and I've had a fairly quick burst of heat and volume reduction down to about 60% within a few days- how can I build on this? The resources on site include:

Tree surgeon woodchips, cardboard, sawdust, and straw.
Charcoal- lots of it.
Aqueous urea solution.
Reclaimed wood for rat-proof lids.
A trommel, currently with a 10mm screen, but that can be easily adapted.

My questions- which may seem naive- I'm approaching this from a waste management and process technology background, rather than a gardening background, would be:

What defines "good" compost?
What timescales do I need to think of to make "good" compost? To just get it to a point where the rats won't be interested, and it can be buried to let the earthworms do the rest? I'm hoping that simply trommeling out the finer particles is the answer.
What creatures should I let in/keep out? Remember, the general idea is to keep things out unless I want them. Are fruit flies to be welcomed or suppressed?
What sort of things will grow well in the resulting compost?

Thanks for any replies.

Thanks for the reply- the questions on my mind are now: where does the heat come from to generate landfill gas, and where can I get reliable 30C heat? A compost mound with a digester vessel buried inside? A wind/solar installation when the batteries are full to capacity? To be continued.....

I'm thinking about condensing out wood tar from retort production of biochar, if for nothing else, as a liquid fuel. The question is, how toxic/carcinogenic is the stuff. Are tars=bad- if they are, why do they love the stuff so much in Finland- they seem to put it in everything. What can I do with a bucket of wood tar?

I'm possibly breaking etiquette by posting a question before I've read through back posts, but on the basis of my (modest) experience with charcoal production, I've been approached by some interested parties about setting up a biodigester- I'd like to get a rough idea about realistic expectations in terms of size, timescale, feedstocks and temperatures. If I start with a 120 litre barrel and horse manure in UK ambient temperatures, roughly how long would it take to generate enough gas to boil a litre of water? Could the process be speeded up significantly by heating and/or insulating? By innoculating with the right bugs? By choosing the feedstocks? Sorry if the question seems rude-I don't intend any discourtesy to anyone's investment in the learning process, but the prospective site has to be considered short life, and I would be a little bit wary about investing time and effort for modest returns.
Thanks for any replies