This week we’ve turned our attention to what we are throwing out. We already recycle our paper, plastic, cans and glass thanks to our local council making it pretty easy with separate collections for all of these. What we noticed is that we were throwing out a lot of food waste every week i.e. peelings, skins, teabags, cores. Rick and I eat a vegetarian diet which means there is a decent amount of vegetable waste produced in our house each week. Kitty is obsessed with mangos currently which has a fair bit of waste when you consider the peel and the stone .The waste goes into our general waste bin which means it’s going into landfill. The average household produces about 100kg of this sort of waste per year.
We wondered whether this was a problem- food is biodegradable right? It turns out that food waste in landfill is a problem and here’s why; anaerobic degradation. Stay with me I’m not about to go into a Biology lesson but it is relevant. Food such as the peel of fruit, broccoli stalks and carrot tops do degrade well but in landfill sites this occurs through anaerobic degradation. This anaerobic breaking down causes production of landfill gas that is rich in methane and carbon dioxide i.e. greenhouse gases. Anaerobic degradation is also much slower than aerobic degradation meaning the waste is around for longer.
In a well maintained compost heap the breakdown is aerobic. This works faster and more efficiently (less gases) than anaerobic breakdown. To achieve this the air supply must be good so that either the compost heap must be open to the surroundings or, if you’re not keen on the aesthetics of this, a well ventilated container. The waste also need to be turned regularly so that oxygen can get to the bottom as the bacteria breaking down the waste use up the oxygen pretty quickly.
Luckily clever inventors have designed composters with drums inside which you can turn every few days which does the hard work for you. We however, have an old school compost bin. The main reason for this being it was already in the garden when we moved in but we’ve never used it until now! We keep it at the back of the garden in an area left deliberately unkempt for bees and other insects so it fits right in!
We’ve carried out some research about maintaining a compost heap so to save you the effort here’s our five tips for a healthy heap:
As covered above we want aerobic fast decomposition of our waste with less greenhouse gases. Aim to turn the heap at least once a week, we do our every couple of times we add some scraps of food. We’ve also poked a few wholes into our old bin to let air in. You can make this even easier with a bin that contains built in rotating drums. There are aerator tools available to make this job easier. You can find out more about this here.
Green waste is that which comes from vegetable peel, garden clippings, grass cuttings etc and provides the nitrogen component of the compost. Brown waste, the dry waste, provides the carbon component and consists of dry leaves, straw, paper, woodchips and cardboard. We usually put our kitchen roll in, old loo roll tubes, tea bags and leaves from the garden. The ratio should be at least 50% brown stuff. It is also good for making pockets of air in your heap- important for point 1.
Worms do a great job of composting so should definitely be encouraged. We’ve moved a few from the garden into the composter but have also left some holes in the bottom of the container to let them in or out. The Eden Project also sells composting worms that you can add to your pile, you can find this here.
Certain things will not break down and don’t belong in your wonderful soil making enterprise things such as nappies and plastic, they are not welcome. Also avoid dog waste and cat waste as they bring with them potential pathogens which can contaminate your compost- not great if you want to use it for your veggies. Meat and dairy products are also best avoided as they break down more slowly and tend to attract vermin.
This really encompasses all of the points above. If there’s too much green waste the heap will be too wet and will smell, too much brown and it will dry with no moisture for the all important bacteria and worms to thrive upon. Regular rotation also prevents build up of moisture and bad smells. One source we read suggests the consistency should be of a wrung wet sponge. So add more green (wet) or brown (dry) waste to achieve what you need.
So there you have it, week three of our eco-exchange challenge. Have you found this article helpful? Do you feel inspired to get composting? Please do get in touch! There’s a lot more you can learn about composting so if you’d like to know more we’ve put some links below to some sites we found helpful whilst writing this post.