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Energy Agriculture - Where’s the Nitrogen?

Don Hofstrand (November, 2007)

Summary

The ethanol industry requires large amounts of corn as a feedstock. A hundred million gallon ethanol plant will require about 35 million bushels of corn annually. By comparison, the average Iowa corn production per county last year was slightly over 20 million bushels. As the ethanol industry expands there will be a strong incentive to expand corn acreage. This will create a substantial increase in the demand for nitrogen fertilizer. Corn is the largest consumer of nitrogen fertilizer accounting for close to half of the total U.S. agricultural usage. Moreover, an increase in corn acreage usually results in a decrease in soybean acreage. Because soybeans are a legume, they symbiotically fix nitrogen with rhizobia bacteria and do not need nitrogen fertilization.