Rotting wood

As a Master Composter and organic gardener I am a friend of decomposers and detritivores – the organisms and microorganisms that process dead matter and waste products into new life. They’re part of the natural circle of life, and the cornerstone of the food web.

Inside the house, it’s a different matter – we’re still very keen on preventing our food from decomposing, and on removing it from the house once it does. So it has been fascinating to watch the BBC Four documentary ‘After Life: The Strange Science of Decay’. In it scientists created a model house, filled it with all kinds of food, sealed it up and left it to see what happened. They released a few insects to seed the populations, but assumed that the rest of the decomposing organisms would already be in position. For eight weeks they tracked every stage of decomposition.

Fortunately, no one has yet invented SmelloVision, so viewers are spared what Pete refers to as ‘bin juice’ – a smell guaranteed to make him hurl. The presenter, Dr George McGavin, is not so lucky, although as a biologist he says he is used to horrid smells. He’s generally fine with the stenches the house produces; it’s on one of his field trips he encounters one that makes him gag.

We watch as bacteria, fungi and insects devour vegetables and meat and leave almost nothing behind (and the remains would, eventually, be eaten by later waves of decomposers). We investigate our deep-seated feelings of revulsion (programmed into us to keep us alive) and look at the important work being done by forensic scientists on the nature of decay.

If you’re squeamish, but interested in composting, then fast-forward to week 8 (about an hour and 20 minutes in), when everything has pretty much decomposed and we get to see inside the compost heap. Not only do you get a good look at some of the microscopic beasties that do such good work for us, but you’ll be able to see the nutrients being recycled into fresh plants.

I would thoroughly recommend watching the show while it’s still available on iPlayer (until 16th December), although perhaps not with a tv dinner.

And if there are any experts out there who can explain why a lack of atmospheric carbon in the Carboniferous period led to GIANT insects, I would be intrigued to know ;)