Get ahead of the carbon curve - garden organically

Keeping food waste from landfill, bins full of composting worms, mindful soil stewardship and less digging can all help ensure a brighter future for our biosphere, says earth-friendly gardening writer John Walker.

You know, I’m sure the worms in my compost bin have got a sense of humour. Now there’s a slight risk that I might be imagining this, but a little while back, after consigning a front page of the Daily Mail to composting nirvana, I’m pretty positive my bin rocked with the hearty cackles of its segmented annelid inhabitants.

They must be laughing a lot of the time – not just when a holed pair of my organic cotton underpants (only the best for my worms) lands in their laps. Each fresh delivery from my compost caddy brings them evidence of our profligate use of resources, as cereal packets, card food packaging, tea bags, scrunched cardboard, envelopes, newspapers, and anything else of organic origin that will (or sometimes won’t) rot away, rain down on these eager compost-creators. I use a ‘cold’ and slow composting system for all this - I just add fresh material to the top of the bin and let the worms, and myriad other life, do the hard work.

Coverage of even the most fundamental and pressing environmental issues in our tabloid newspapers is, as a rule, given short, superficial shrift; the modus operandi of these publications (apart from being useful compost material) is to provide sensationalist headlines that reassure the great washed that environmental concern equates to an attack on their readers’ freedom. One such story had my worms sliding over themselves with laughter.

‘A slop bucket for every home,’ yelled the Daily Mail. ‘Ministers plan to impose fines if you don’t recycle food waste’. Shock, horror. The government is planning to reduce some of the mountain of food waste that goes to landfill each year in the UK, which, when mixed with everything else we bury out of sight and mind, produces, amongst other insidious pollutants, methane, a global warming gas 20 times more potent than carbon dioxide (CO2). It is currently investigating whether food waste can be collected and redeployed away from our traditional ‘dump and forget’ waste streams.

As the worms’ laughter subsided and they munched their way merrily through the words ‘slop bucket’, headlines flashed of an altogether more intelligent but also more disquieting nature: we’re losing 2.2 million tonnes of the UK’s topsoil each year, mostly through erosion by wind and rain. Our emaciated farmland and forest soils, starved of organic matter, are blowing and washing away. A government strategy document (PDF) has identified the root causes, unsurprisingly, as intensive farming and industrial pollution. This is doubtless mirrored in gardens and allotments across the land; chemical- and fertiliser-addicted gardening knocks the stuffing out of that thin, life-giving layer of brown stuff, just like feed-the-plants, forget-the-soil farming has done.

What’s ringing alarm bells at the Department for Environment, Food and Rural Affairs (DEFRA) is concern over how the UK is going to feed itself in the future. With our agricultural soils in a dire state, the prognosis for increasing the amount of food we grow as a nation isn’t looking good.

DEFRA estimates that our soils lock away (‘sequester’, in boffin-speak) around 10 billion tonnes of carbon (half of it in peat bogs), with huge potential for it to lock up even more. And just as my worms burped after swallowing the last bits of the Daily Mail, along came another, more deeply worrying headline, this time from the Met Office, warning of ‘catastrophic global warming in our lifetimes’.

Scientific estimates have tended to psychologically shunt the effects of severe climate change off into the yet-to-be-lived lives of future generations, but new research from climatologists is bringing us down to earth with a bump. Our fossil fuel-driven lives (which show no sign of abating) could mean that folk alive today might well witness, following a 4C rise in temperature, the loss of up to half of the planet’s species, threats to the water supplies of half the world’s population, and the swamping of low-lying coastal communities. If you plan on being around in 2060, take note; there’s a real chance you’ll witness this planetary fever for yourself.

One increasingly important strand of thought as to how we might still avert climate breakdown (apart from drastically reducing CO2 emissions) is to find ways of removing the carbon that’s already there. One of the best and easiest ways, as soil scientists will tell you, is to add composted organic matter to the soil, and practice ‘minimum tillage’. (The Soil Association recently recently published a ground-breaking reportreviewing the evidence of agriculture's potential to mitigate climate change.)

In gardening speak, that means making compost as if our biosphere’s health depended on it, and avoiding the annual ritual of chopping up that precious skin of soil, on which our very existence depends. When you dig soil, you not only turn a fragile ecosystem repeatedly on its head, you expose the soil to the air, which turns organic matter to CO2. This drifts away unseen, helping to ease up the global thermostat. Hold on to your cloth caps, but we are no longer in the age of the spade.

If the government does go ahead with its plans to collect food waste, I’ll be declining their offer of a ‘slop bucket’. On the rare occasions that I ‘waste’ food, it goes straight into the compost caddy and then into my compost bin. ‘Slop’ is anathema here, and I’m not big on bins. I have no wheelie bin. Not possessing one of these malodorous vessels of our ‘dump and forget’ mentality helps to tune you out of throwaway thinking, and into ‘can I compost it?’ awareness. Only if the worms can’t turn it into energized, soil-building compost, and it can’t be recycled, does any waste get, reluctantly, thrown away. A vegetarian diet will spare you the dilemma of what to do with bones and stuff – even determined tiger worms find those tough going.

So there’s one alarmist headline sorted: rather than spend zillions foisting a ‘slop collection’ system on a reluctant public, why not show them how to turn their ‘slops’, along with all the garden ‘waste’ (aka valuable resource) that they religiously ram into their brown wheelie bin, into a rich, ultra-local soil food?

Cue the laughing boys. Fast-moving, red and thrashing composting worms will find a bin wherever you put it, and will soon turn all of your garden and kitchen ‘waste’, plus a good deal else (including tabloid newspapers) into rich, worm-worked organic compost. Adding this regularly to your soil will grow you healthy, resilient and nutrient-rich crops, and even more importantly, as your soil becomes ever more enriched with organic matter, and remains as undisturbed as possible, it will be able to lock up increasing amounts of carbon. In just a few years, compost from my worm-filled bins has helped transform my virgin soil from red, acid and nutrient-less, to dark, crumbly and fertile (see image).

Organic gardeners have been nurturing and improving soil for far longer than forget-the-soil farmers and gardeners have been abusing it, so we can greet government headlines about vanishing soils with a philosophical shrug. But the realisation that the soil in our gardens and allotments, if we care for it mindfully, might actually help us do our bit toward staving off climate breakdown, brings added gusto to our determination to garden in not just an earth-friendly way, but an earth-cooling one.

Right now, bods from 200 countries are attending the 15th meeting of the parties to the United Nations Framework Convention on Climate Change in Copenhagen. The outcome of this mega-meeting will test whether humanity can pull together to avert changes to our climate that will affect every species on earth, from humans to composting worms. Who’d have thought that organic gardeners would be ahead of the curve when it comes to cutting carbon.

Now there’s a headline that’s truly sensational.

This slightly amended article was first published in Kitchen Garden magazine, December 2009. Text and images Copyright John Walker.