For the most accurate accounting of a product’s environmental impact, scientists look at the product’s entire life cycle, from cradle to grave.
For the most accurate accounting of a product’s environmental impact, scientists look at the product’s entire life cycle, from cradle to grave. It’s a grand calculation known as a life cycle assessment (LCA), and greenhouse gas emissions are a key component.
For corn ethanol, most greenhouse gas emissions can be mapped to the fuel’s production, transportation, and combustion, but a large portion of the greenhouse gas calculation can be traced right back to the farm. Because of privacy concerns, however, scientists can’t access individual farm management decisions such as fertilizer type and rate.
Nitrogen fertilizer data are an important piece of the calculation because a portion of these fertilizers wind up in the atmosphere in the form of nitrous oxide, a highly potent greenhouse gas. Corn nitrogen fertilizer data are publicly available at the national and state levels, but scientists argue this level of resolution masks what’s really being applied on farms across the country and could lead to inaccurate LCAs for corn ethanol.
In a new study from the University of Illinois and the U.S. Department of Energy’s Argonne National Laboratory, researchers developed the first county-level nitrogen application datasets for corn, dramatically improving the accuracy of greenhouse gas calculations for the crop.
Image: Researcher Yushu Xia (pictured) and others from the University of Illinois and Argonne National Laboratory have mapped nitrous oxide emissions from corn fertilizers to the county level, allowing greater precision in life cycle analysis for corn ethanol. (Credit: Yushu Xia, University of Illinois)