Most U.S. corn acres at risk of nitrogen losses to the environment
Corn is the most widely planted crop in the U.S. and the largest user of nitrogen fertilizer. By using this fertilizer, farmers can produce high crop yields profitably; however nitrogen is also a source of environmental degradation when it leaves the field through runoff or leaching or as a gas. When the best nitrogen management practices aren’t applied, the risk that excess nitrogen can move from cornfields to water resources or the atmosphere is increased. Nitrogen management practices that minimize environmental losses of nitrogen include applying only the amount of nitrogen needed for crop growth (agronomic rate), not applying nitrogen in the fall for a crop planted in the spring, and injecting or incorporating fertilizer into the soil rather than leaving it on top of the soil. In 2010, about 66 percent of all U.S. corn acres did not meet all three criteria. Nitrogen from the Corn Belt, Northern Plains, and Lake States (regions that together account for nearly 90 percent of U.S. corn acres) contribute to both the hypoxic (low oxygen) zone in the Gulf of Mexico and to algae blooms in the Great Lakes. This chart is based on data found in the ERS report, Nitrogen Management on U.S. Corn Acres, 2001-10, EB-20, November 2012.
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