Monday, December 7, 2009
Sustainable Soil: How Farming Practices Can Moderate Climate Change
Everyone forgets about soil. Yes, we walk on it and we wash traces of it off of our food, but other than that we try to ignore it, sweeping it off of our floors with a look of disgust. Soil doesn’t get a lot of respect in most circles. But given the talks about climate change in Copenhagen, perhaps that is about to change. As leaders look at ways to reduce climate change and plan for its impacts, thinking about ways to reduce our carbon emissions and use them up, they may turn towards the rich soil of the world’s farms for answers.
Soil is a carbon sink. We’re all told to plant trees to soak up the nasty stuff in the atmosphere, but the world’s forests sequester only one-fifth the amount of carbon that soil sequesters. According to a study from the UK’s Soil Association, using organic methods of farming helps boost the soil’s ability to be a carbon sink, making it sequester nearly 30% more carbon. Worldwide, a switch to organic farming would help sequester 11% of greenhouse gas emissions, which is a stunningly large amount.
Humus? No, it’s not the chickpea-based spread. It’s the decaying organic matter found in soil. Organic farming uses green manure, animal manures, cover crops and other composting techniques to build soil humus. This is where a lot of the soil carbon is stored. That brown, rich soil is rich in carbon as well, and it keeps that carbon under wraps. Organic farming techniques also create soil that is very porous, allowing the soil to accommodate the water from storm events. This will also be useful as climate patterns change – if storms are going to become more frequent, having soil that can moderate the flow of water effectively will reduce flooding.
As we count down the last days to the Copenhagen Summit on climate change, we should give our soil some respect. Let’s make it one of the main players in the work to moderate our greenhouse gas emissions. In addition to asking children to go out and plant a tree on Earth Day, we should ask them to support local, organic farming practices and create their own garden with rich compost. The climate impacts of both actions are small but profound. Let’s raise our hands and speak out about good soil: the decaying brown stuff that may just have a large role to play not only in .growing healthy vegetables but in creating a healthier atmosphere as well.