Monday, January 5, 2015

It's All About that Soil

It's all about that soil, 'bout that soil, no dirt. But seriously, soil is the foundation of our planet's natural and human dominated ecosystems. During one of the first lectures in my undergraduate soils class, the professor emphatically stated that 'soil' and 'dirt' are too often, and incorrectly, used interchangeably. Dirt is the lifeless collection of silt, sand, and clay particles - a soil taken out of context - often with negative connotation bestowed upon it. Soil, on the other hand, is what results from the interaction of climate, topography, biology, and geology, continually evolving over time. So as much as the Banana Slug String Band would like you to believe, dirt did not make your lunch.
However, soil does make our lunches. The composition (whether it's particularly heavy in clay or high in organic matter) dictates how much water stays in the ground and is available to plants and animals. Microbes, such as nitrogen-fixing bacteria, make essential nutrients available to plants. Other small soil critters - ranging from microscopic organisms to earth worms - break down dead plants and animals to recycle their component parts. What is in the ground directly reflects what will end up in plants and thus our food. Soil is everything. In the words of the International Institute for Environment and Development director in a recent interview, "if you get soil management wrong, you get hunger, you get famine, you get rising food prices..."
Click for nifty infographic
My activities last week included a long overdue farm visit. Settling in for the winter ahead, only some stalks of brussels sprouts and rows of hardy greens gave any signal about the bounty over the summer. The ground had frozen over, so the remnants of parsnips and leeks presented a challenge to unearth. But, I also saw fields currently under "soil-building" phases, covered in vetch and rye that will be plowed under before planting the next round of vegetables in March or April. These covercrops, or "green manures", add nitrogen and carbon to the soil while protecting it from erosion during heavy winter rains and winds. 

On the way back to town, we got to talking about the past year and the importance of having good soil in order to have a successful year of crops. For the smallscale organic farmer there may be nothing so important as the soil. When conditions - sunshine, rain, temperature - are optimal, there really is no competing with conventional agriculture and its pesticides, herbicides, and fertilizers. But in years that don't meet these narrow standards, healthy soil may be the key to moderating things like insufficient or excess rains or disease outbreaks. This is not to say that there aren't versions of synthetic chemicals used in organic agriculture. Yet where robust soils are a main objective, the farming system may experience higher resilience over time.

Two years ago I welcomed in the new year with a post on compost and soils. This year it seems even more appropriate as we embark on the International Year of Soils. The United Nations has this tendency to attach certain themes to days, weeks, years, and even decades in order to heighten awareness. For example, we just concluded the International Years of Family Farming and of Solidarity with the Palestinian Peoples, and just entered the United Nations Decade of Sustainable Energy for All. While soil scientists (and potentially agronomists) may have an unabounding enthusiasm for the earth beneath our feet, the rest of the world does not fully appreciate its importance. As soils around the world become increasingly degraded and depleted, it is probably about time that the topic made its way into more mainstream discussions. Here's to a fertile year ahead!

Read/Hear/Watch More:
No Ordinary Matter - Montpellier Panel (report)
Soil Food Web - Lexicon of Sustainability (infographic)
Let's Talk About Soil - Global Soil Week (animated video) 
Soil: The Foundation of Agriculture - Nature (online article)

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