Welcome Kristin Ohlson, the New York Times free-lance journalist and writer!
Monday, 27 October, 2014
Starting this week we are hosting guest posts on various educational topics.
Please, enjoy this guest post by journalist and writer Kristin Ohlson on environmental sustainability.
The New York Times free-lance journalist and bestselling author, Kristin Ohlson in The Soil Will Save Us, makes an elegantly argued, passionate case for “our great green hope”—a way in which we can not only heal the land but also turn atmospheric carbon into beneficial soil carbon—and potentially reverse global warming.
CAN HEALTHY SOIL FIX OUR PLANET AND REVERSE GLOBAL WARMING?
A few days ago, a homeless man pulling a red wagon full of gardening tools stopped by my house in Portland, Oregon, wanting work. I told him I’d pay him to rake the fall leaves from the sidewalk into my flowerbeds. “You don’t want me to bag up the leaves?” he asked. “Most people want their beds nice and tidy for winter.”
No, I told him. Messy is fine. The microorganisms in the soil don’t care if it’s tidy upstairs. They just want something to eat.
Ever since I began working on my book about the ancient partnership between plants and soil microorganisms, I look at our ecosystem and what it needs from me differently. I’ve always loved the sights, sounds, smells and touch of nature, but my appreciation was limited to what I could see above ground. Now I’m gloriously aware of the life underground—with some six billion microorganisms in a mere teaspoon of soil, found as far down as ten miles below ground– and of its potential to heal much of the damage we’ve done to our planet.
Ever since plants moved to the land a half-billion years ago, they’ve carried on a partnership with the bacteria, fungi, protozoa, and other microscopic organisms in the soil. Plants conduct photosynthesis, taking carbon dioxide from the air and creating a carbon fuel to help them grow, flower, and carry on many tasks. But they shunt up to 40% of that carbon fuel to their roots, where they share it with the soil microorganisms – that’s their contribution to the partnership. For their part, the soil microorganisms bring minerals they’ve scavenged from stone and make them accessible to the plant. This is how plants have been fertilized for millennia.
Through this exchange, carbon becomes fixed in the soil – when you see dark, rich soil, that’s the buildup of carbon that the plants have shared with the microorganisms. Before humans began changing landscapes with agriculture, most soil was dark like this. It was also wonderfully friable since those vigorous communities of soil microorganisms secrete a carbon glue and create habitat out of sand, silt and clay to protect themselves and maintain pockets of water and air in the soil. The result of this micro-engineering? Billions of tiny cups and saucers underground, maintaining a balance of moisture and gas that both microorganisms and plants need.
Many of us tend to think that only industrial agriculture is hard on the land. And it’s true that aggressive modern tilling and chemical use is the most effective way to ruin land that humans have devised. But even a pair of bullocks pulling a wooden plough damages soil. Creating that furrow disrupts the community of soil microorganisms and destroys their cups and saucers, and it exposes all that stored carbon to the air. The soil carbon oxidizes and becomes carbon dioxide. Some scientists estimate that 80 billion tons of carbon dioxide have been loosed from the land into the atmosphere over the millennia. Some parts of the world have lost 80% of their soil carbon. Land use still contributes some 30% of humanity’s annual greenhouse gas emissions.
That’s the bad news: we often make the planet sicker by carrying on the noble and beautiful task of raising food. But the good news is that we can raise our food differently, in a way that heals the land. Thanks to new science, we understand how supporting the partnership between plants and soil microorganisms can help us tackle many seemingly intractable problems – climate change, poor water and air quality, poor food quality, even flooding and fire. Thanks to innovative farmers around the world, we’re learning how to conduct agriculture by mimicking nature and respecting all the vital partnerships there.
The United Nations’ Food and Agriculture Organization has declared December 5 as World Soil Day and 2015 as the International Year of Soils. It seems that now is the moment for soil. If you’re looking for hope, you may just find it under your feet.
By Kristin Ohlson
Follow Kristin on her site: www.kristinohlson.com
And on twitter @kristinohlson