Soil Carbon

Not all carbon in biomass is recycled back to the atmosphere. Forest fires and brush fires leave charcoal (biochar) behind. It takes years for biochar to oxidize when exposed directly to the atmosphere. And, when biochar becomes buried beneath the surface of the earth (soil carbon) it can take centuries, or millennia, to oxidize.

Biochar is different from charcoal, in that “Charcoal” is produced for fuel; it is intended to be burned, often in a family barbecue. Biochar is not intended to be used as fuel, if it was, its carbon would be returned to the atmosphere.

Biochar Soil Enhancement

Biochar produced by Carbon Farms can be processed and systematically buried on unproductive land — Land that is useless for farming (marginal land or desert land) can be converted to rich agricultural land over time through biochar soil enhancement.

Soil enhancement is not the same as fertilizer—the benefits of buried biochar will take years (Contact University researchers for more details). Large-scale biochar soil enhancement will be a gift for future generations, one that gives the present generation a practical method for reducing atmospheric carbon today by making fossil fuels burned in automobiles, effectively carbon neutral.

Marginal land would be excavated to a depth of six feet or greater, for the purpose of burying biochar. The dirt removed by excavation would be mixed with biochar and other organic waste, and possibly additional soil bacteria. After mixing, the enhanced dirt would be put back in the ground.

Five hundred pounds of biochar can be included (mixed) in one cubic yard of enhanced dirt; the percent of biochar in the mixture would then be about 15-20% by weight. A square yard area six feet deep will hold two cubic yards. An acre of land is 4,840 square yards; and if excavated six feet deep, an acre can hold 9,680 cubic yards of enhanced “dirt” sequestering 500 pounds of biochar per cubic yard.

4,840 square yards multiplied by 2 yards deep equals 9,680 cubic yards per acre; at 500 pounds of biochar per cubic yard, one acre six feet deep would hold 4,840,000 pounds of biochar. One U.S. ton (short ton) weighs 2,000 pounds. 4,840,000 divided by 2,000 equals 2,420 tons of biochar per acre.

In order to make the U.S. transportation sector carbon-neutral, Carbon farms would need to produce and bury 500 million tons of biochar per year. 500,000,000 tons divided by 2,420 tons per acre would require 206,612 acres of marginal land per year to “bury” the biochar.

After the biochar has been mixed into the soil, it will take several years before the biochar and bacteria in the soil reach optimal conditions for agriculture use; so, until then, 206,612 acres of new switchgrass or other high-yield biomass, such as fast-growing trees, could be planted each year over the newly “soil enhanced” acreage, to make use of the land.

Switchgrass has been identified by the DOE as a primary crop for bioenergy development because of its potential for high yields and its ability to grow on marginal cropland without intensive management. Switchgrass, a perennial native North American tall prairie grass, reaches full maturity in about three years, producing 5-10 tons of biomass per acre, and switchgrass roots extend 8-10 feet deep, accounting for more than 80 percent of the plant’s biomass, increasing organic carbon within the soil.

At 200,000 plus acres of enhanced soil development per year, after ten years, over two million acres of marginal land will have been converted to potentially valuable cropland that will remain productive for generations. In 100 years, over 20 million acres of U.S. land would have been “enhanced” for agricultural use.

How much will it cost and who will pay for it?

A guarantee from the U.S. Government to purchase Biochar made from home-grown USA biomass, including forest residue, agricultural waste, and organic waste sent to public landfills, for $100 per ton (with long-term contracts) would attract the private capital investment required to build the Carbon farms and pay for the pyrolysis equipment. So, the cost of the Carbon farms and pyrolysis equipment should not be a concern if a market for the biochar is assured

500 million tons of biochar per year at $100 per ton will cost 50 billion dollars annually. [Approximately equal to the cost of five months of military operations in Iraq.]

The money to pay for the biochar and to fund the soil enhancement program would come from a fee charged to wholesale fuel distributors. Which means the money would not need to come from the federal treasury. Using an acronym derived from the full name Atmospheric Carbon Extraction and Sequestration the fee would be called the ACES fee.

Continue reading on next page ——> ACES

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Additional Recommended Reading:
Can ‘biochar’ save the planet? — “Biochar is considered by many scientists to be the ‘black gold’ for agriculture. Its high carbon content and porous nature can help the soil retain water, nutrients, protect soil microbes, and ultimately increase crop yields while acting as a natural carbon sink – sequestering CO2 and locking it into the ground.

What Is Soil Carbon Sequestration? —“Soil carbon sequestration is the process of transferring carbon dioxide from the atmosphere into the soil through crop residues and other organic solids, and in a form that is not immediately reemitted. This transfer or ‘sequestering’ of carbon helps offset emissions from fossil fuel combustion and other carbon-emitting activities while enhancing soil quality and long-term agronomic productivity… Carbon is a key ingredient in soil organic matter (57% by weight). Plants produce organic compounds by using sunlight energy and combining carbon dioxide from the atmosphere with water from the soil. Soil organic matter is created by the cycling of these organic compounds in plants, animals, and microorganisms into the soil. Well-decomposed organic matter forms humus, a dark brown, porous, spongy material that provides a carbon and energy source for soil microbes and plants.

Charcoal takes some heat off global warming — “Biochar can offset 1.8 billion metric tons of carbon emissions annually” – Pacific Northwest National Laboratory.

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