Jason Hill And G. David Tilman on Minnesota prairie biofuels

[jpak]

http://www.startribune.com/562/story/1060375.html

A little more than a century ago our personal transportation in this country (horses) was fueled by the products of agriculture (hay and oats). When automobiles came along, we tried fueling them with corn ethanol, but gasoline has always been the cheaper alternative. • Today, however, we know that fossil fuels are finite and that burning them contributes to destructive global warming. And so it is back to the future: Corn ethanol and, to a lesser extent, soybean biodiesel have emerged as leading candidates to reduce our nation's use of oil. • There are serious concerns, however, about how these biofuels will impact the environment -- and about the wisdom of trying to use our corn and soybean crops to meet both the food and energy needs of the world's growing population. Global population, which has quadrupled since 1900, is expected to increase by 3 billion over the next 50 years. Energy and food consumption will at least double as those in China, India and other developing countries seek to emulate our lifestyle. • Research that we have conducted at the University of Minnesota shows that there might be even better alternatives to corn- and soybean-based fuels, and it puts us in a better position to make decisions about energy use that will affect future generations.

In July 2006, we published a report in Proceedings of the National Academy of Sciences on the costs and benefits of corn ethanol and soybean biodiesel. Soybean biodiesel has significant advantages over corn ethanol, yielding 93 percent more energy than the fossil fuel energy that is used to produce it, compared with 25 percent for corn ethanol. Soybean biodiesel produces 41 percent less greenhouse gas emissions than diesel, while corn ethanol produces only 12 percent less emissions than gasoline.

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But our research did not end there. In a recent issue of Science, we published research showing that mixtures of native prairie plants grown on marginal land are a good source of biomass for biofuel. Our study, based on 10 years of biodiversity experiments at Cedar Creek Natural History Area near East Bethel, demonstrated that ethanol made from mixed prairie plants can provide more usable energy per acre than either corn ethanol or soybean biodiesel.

In addition, mixed prairie plants are highly productive and easy to grow. As they are perennial, they don't need to be replanted each year. Certain species in these mixtures, such as legumes, interact with soil bacteria to "fix" their own nitrogen from the atmosphere just as soybeans do. These diverse mixtures also prevent soil erosion and don't require pesticides, herbicides or irrigation. They remove carbon dioxide from the air, storing carbon in their massive root systems as organic matter and in the soil itself. This actually adds fertility to degraded lands.

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[efhmc]

1. This is why I do not understand the blowup over using corn as if it is

the only or easiest or least soil destructive crop to use. People are so single minded. Thank you for the information.