Recruiting soil to tackle climate change
There are some unsung heroes waiting in the wings to tackle climate change, and they're a very powerful combo – soil and the organic matter which is produced at compost and anaerobic digestion facilities across Canada.
"Recruiting Soil to Tackle Climate Change: A Roadmap for Canada" identifies the enormous, positive opportunity for soil to combat the climate crisis. Jointly written by the Soil Conservation Council of Canada and our Council, with support from the Metcalf Foundation, the report identifies that Canada's soils - about 71 million hectares of managed agricultural and urban soils - have the potential to completely offset agriculture's greenhouse gas emissions footprint, currently estimated at 73 megatonnes annually.
Focusing on soil and using it to sequester carbon delivers important co-benefits including increased fertility, cleaner water, and enhanced biodiversity. For our farmers, it will also create greater resiliency and profitability.
Over two years in the development, with input from soil health researchers and practitioners from across Canada, the road map identifies methods and recommended actions to rally healthy soils to increase and retain more carbon.
Central to the report are five fundamental principles, including minimizing soil disturbance, keeping the ground covered, and adding organic matter (such as compost) to the soil to optimize inputs. All have a common objective: to protect and enhance the community of beneficial soil organisms known as the soil food web.
Compost has an extremely important role to play in helping the soil food web do its job. Not only does compost provide energy and nutrition for the soil food web, but it also boosts microbial diversity. Plus, as shown in the multi-year agricultural research using CQA compost produced from the source-separated residential organics recycling program in Brandon, Manitoba, the nutritional value of the food crops grown in compost is dramatically improved.
Unavoidable food waste, leaf and yard trimmings, and other organic residuals should be recycled and transformed into soil-destined products, from digestate and ultimately, compost. And the benefits are enormous - from massive landfill diversion gains, methane emission reductions, and improved leachate management, to local economic gains including farmland profitability through productivity gains and reduced inputs, better soil health, improved plant yields and nutrient advantages, enhanced water quality and conservation, with another benefit being the very real delivery of carbon sequestration.
And yet we're sitting around at a recycling rate of about one-third of our annual potential. Communities of all population sizes have stepped up to make organics recycling a key component of their local environmental care. These are examples which can be emulated and made locally relevant for those who have yet to step up.
As for businesses - the sector which generates two-thirds of the waste produced annually in Canada - there are lots of words about sustainability. While the words from business are deafening, the actions in this arena are too few and far between. Many who package their goods for either business or consumer consumption are irresponsibly interpreting the guidelines for compostability claims with limited consequences for doing so.
Over 30 years have gone by since the early days of waste composition audits and recommendations. At what point does all the proof turn into wholesale action to recycle organics and return the essential organic matter back to our soils in a quality manner?
Susan Antler is the executive director of the Compost Council of Canada.
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