| Think for a moment about photosynthesis. A plant takes water and CO2 and makes sugar, a carbohydrate. In fact, the word carbohydrate is nothing more than carbon + water (hydrate). Hydrated carbon. And when that plant decays, the carbon that it took from the atmosphere becomes part of the soil.
You've probably heard in various science classes throughout your life that we're eroding the soil. We're taking the carbon from the soil and putting it into the air. We want to put it back into the soil. The Rodale Institute provides a roadmap for how to do this.
There are two methods offered in the PDF I've linked to above. One involves manure, the other involves cover cropping. We saw a field that had been planted with a plant called hairy vetch. Hairy vetch takes nitrogen from the air and fixes it into the soil. Manure also puts nitrogen into the soil. Corn requires a lot of nitrogen to grow, and since organics don't use petroleum based fertilizer, the manure or cover crop provides the nitrogen instead.
If your cornfield-to-be is full of hairy vetch, you've got a bit of a problem: how do you get rid of the hairy vetch without having to do extra work? The Rodale Institute invented a fairly inexpensive (as far as farm equipment goes) device called a roller crimper that takes care of the hairy vetch for you. It rolls over it and cuts it up without tilling the soil.
Roller crimper
If you wait until the right point in your cover crop's life cycle to roll over it, it won't spring back to life even though you haven't uprooted it. Put the roller crimper on the front of the tractor and the thing that plants the corn on the back of the tractor, and it only takes one trip around the field to get rid of hairy vetch and plant corn. The dead hairy vetch stays on the ground as a mulch, keeping weed seeds from getting any sunlight and enriching the soil.
Both manure and cover crops contain carbon, so as they decay, they put carbon into the soil that was once in the atmosphere. The same can be said for compost, if you use that too. All in all, the Rodale Institute says that every 2 acres of organic ag is like taking 1 car off the road. If we converted all of the world's tillable acres to organic (using Rodale's methods), we would take 40% of emissions out of the air.
There are two more bits of good info about Rodale's organic ag methods as well. First, if a farmer moves from conventional methods (with tilling) to organic no-till methods, he or she reduces the amount of fossil fuels required by two thirds. Second, five years after ditching the toxic chemicals, organic yields equal conventional yields. In most years after that, organic yields surpass conventional yields.
When I visited Rodale, I could see with my own eyes the organic corn stood taller than the conventional corn, and the ears of organic corn were much bigger than the conventional corn. Amazing!
The smaller ear is conventional GMO corn; the larger ear is organic corn. The reason the small ear is more yellow is because it was planted earlier - the organic ear will become more yellow with time. You can also see the organic ear had some damage from a pest. Our tour guide said this was because it was on the perimeter of the corn field where it was most vulnerable.
Organic corn
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