Peak Soil

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Ethanol is an agribusiness get-rich-quick scheme that will bankrupt our topsoil.

Nineteenth-century western farmers converted their corn into whiskey to make a profit. Archer Daniels Midland, a large grain processor, came up with an equivalent scheme in the 20th century. But ethanol was a product in search of a market, so ADM spent three decades relentlessly lobbying for ethanol to be used in gasoline. Today ADM makes record profits from ethanol sales and government subsidies.

Fuels made from biomass are a lot like the nuclear powered airplanes the Air Force tried to build from 1946 to 1961, a project which cost over a billion dollars. The planes never got off the ground. The idea was interesting -- atomic jets could fly for months without refueling. But the lead shielding to protect the crew and several months' worth of food and water made the plane too heavy to take off. The weight problem, the ease of shooting this behemoth down, and the consequences of a crash landing were so obvious, it's amazing the project was ever funded, let alone kept going for 15 years.

Biomass fuels have equally obvious and predictable reasons for failure.

With every step required to transform a fuel into energy, there is less and less energy yield. For example, to make ethanol from corn grain, which is how all US ethanol is made now, corn is first grown to develop hybrid seeds, which next season are planted, harvested, delivered, stored, and preprocessed to remove dirt. Dry-mill ethanol is milled, liquefied, heated, saccharified, fermented, evaporated, centrifuged, distilled, scrubbed, dried, stored, and transported to customers.

A current field of experimentation is with the possibility of using the corn residues, or "stover" for ethanol production, instead of the edible part of the plant. However, fertile soil will be destroyed if crops and other "wastes" are removed to make this "cellulosic ethanol."

Fuels from biomass are not sustainable, are ecologically destructive, have a net energy loss, and there isn't enough biomass in America to make significant amounts of energy because essential inputs like water, land, fossil fuels, and phosphate ores are limited.

Soil Science 101: There is no "waste" biomass

Long before there was "peak oil," there was "peak soil." Iowa has some of the best topsoil in the world. In the past century, half of it has been lost, from an average of 18 to 10 inches. Productivity drops off sharply when topsoil reaches 6 inches or less, the average crop root zone depth.

Erosion removes the most fertile parts of the soil. Underground creatures and fungi break down fallen leaves and twigs into microscopic bits that plants can eat, and create tunnels air and water can infiltrate. When plants die, they're recycled into basic elements and become a part of new plants. There is no bio-waste.

If you dove into the soil and swam around, you'd be surrounded by miles of thin strands of mycorrhizal fungi that help plant roots absorb nutrients and water, plus millions of creatures, most of them unknown. There'd be thousands of species in just a handful of earth -- springtails, bacteria, and worms digging airy subways. As you swam along, plant roots would tower above you like trees as you wove through underground skyscrapers. Soil creatures and fungi act as an immune system for plants against diseases, weeds, and insects -- when this living community is harmed by agricultural chemicals and fertilizers, even more chemicals are needed in a vicious cycle.

When tractors plant and harvest, they crush the life out of the soil. The tracks left by tractors in the soil are the erosion route for half of the soil that washes or blows away.

Crop productivity declines as topsoil is lost and residues are removed. If the residues are harvested, the soil becomes vulnerable to erosion if it rains, because there's no vegetation to protect the soil from the impact of falling raindrops. Rain also compacts the surface of the soil so that less water can enter, forcing more to run off, further increasing erosion. By contrast, water landing on dense vegetation soaks into the soil, increasing plant growth and recharging underground aquifers.

Corn biofuel -- especially harmful

Corn Biofuel (butanol, ethanol, biodiesel) is especially harmful for several reasons. Row crops such as corn and soy cause 50 times more soil erosion than sod, because the soil between the rows can wash or blow away. Corn uses more water, insecticide, and fertilizer than most crops. And due to high corn prices, continuous corn (corn crop after corn crop) is increasing, rather than rotation of nitrogen fixing (fertilizer) and erosion control sod crops with corn.

Some farmers now want to plant corn on highly erodible, water-protecting, or wildlife-sustaining Conservation Reserve Program land. Farmers have hitherto been paid not to grow crops on this land. But with high corn prices, farmers are now asking the Agricultural Department to release them from these contracts.

Soil scientists weigh in

I asked 35 soil scientists why topsoil wasn't part of the biofuels debate. These are just a few of the responses from the ten who replied to my off-the-record poll (no one wanted me to quote them, mostly due to fear of losing their jobs):

"I have no idea why soil scientists aren't questioning corn and cellulosic ethanol plans. Quite frankly I'm not sure that our society has had any sort of reasonable debate about this with all the facts laid out. When you see that even if all of the corn was converted to ethanol and that would not provide more than 20% of our current liquid fuel use, it certainly makes me wonder, even before considering the conversion efficiency, soil loss, water contamination, food price problems, etc."

"Biomass production is not sustainable. Only business men and women in the refinery business believe it is."

"Should we be using our best crop land to grow gasohol and contribute further to global warming? What will our children grow their food on?"

"As agricultural scientists, we are programmed to make farmers profitable, and therefore profits are at the top of the list, and not soil, family, or environmental sustainability."

"Government policy since WWII has been to encourage overproduction to keep food prices down (people with full bellies don't revolt or object too much). It's hard to make a living farming when the selling price is always at or below the break-even point. Farmers have had to get bigger and bigger to make ends meet since the margins keep getting thinner and thinner. We have sacrificed our family farms in the name of cheap food. When farmers stand to make a few bucks (as with biofuels) agricultural scientists tend to look the other way."

"You are quite correct in your concern that soil science should be factored into decisions about biofuel production. Unfortunately, we soil scientists have missed the boat on the importance of soil management to the sustainability of biomass production, and the long-term impact for soil productivity."

Natural gas in agriculture

When you take out more nutrients and organic matter from the soil than you put back in, you are "mining" the topsoil. The organic matter is especially important, since that's what prevents erosion, improves soil structure, health, water retention, and gives the next crop its nutrition. Modern agriculture only addresses the nutritional component, by adding fossil-fuel-based fertilizers, and because the soil is unhealthy from a lack of organic matter, copes with insects and disease with oil-based pesticides.

Agriculture competes with homes and industry for fast-diminishing North American natural gas. We should return crop residues to the soil to provide organic fertilizer, instead of increasing the need for natural gas fertilizers by removing crop residues to make cellulosic biofuels.

Where do we go from here?

There are better, easier ways to stretch out petroleum than adding ethanol to it. Just keeping tires inflated properly would save more energy than all the ethanol produced today. Reducing the maximum speed limit to 55, issuing consumer driving tips, and many other measures can save far more fuel in a shorter time than biofuels ever will, far less destructively. Better yet, Americans can bike or walk, which will save energy used in the health care system.