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YOUR TURF
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Your nitrogen footprint
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James Galloway, Ph.D., has received the Tyler Prize for his work on excessive reactive nitrogen in the environment. Photo by Jane Haley |
If the gentleman in the photo does not look familiar to you, don’t be surprised. The topic he has brought to the forefront of the environmental debate is probably unfamiliar as well.
Regular readers of GCM have seen our initial column on your carbon footprint (GCM, December 2006, Page 28), which was followed this year by a column on your water footprint (GCM, June, Page 44). Now we present another concern — your nitrogen footprint.
Back to the gentleman in the photo. James Galloway, Ph.D., is a professor in environmental science at the University of Virginia. This past February, he was awarded the Tyler Prize for Environmental Achievement, which, according to its Web site, is “the premier award for environmental science, energy and medicine conferring great benefit upon mankind.” Galloway was honored for developing the concept of the “nitrogen cascade,” which “describe(s) the impacts of fertilizer and fossil fuel byproducts” on the environment.
Inert or nonreactive nitrogen makes up about 78 percent of the earth’s atmosphere and about 3 percent of the human body. However, human beings have converted that nonreactive nitrogen to reactive nitrogen (for example, ammonia), mainly for fertilizers and fuels. Reactive nitrogen, the source of the problems described by the nitrogen cascade, is being added to the environment at an alarming rate. In 2005, approximately 187 million metric tons of nitrogen were emitted worldwide, up from 156 million in 1995.
Galloway describes the nitrogen cascade as the journey of a single atom of nitrogen through the environment. That single atom causes “a cascading sequence of events” that harms the environment. In Galloway’s scenario, the atom starts its journey as a component of exhaust from a single automobile. The atom is released into the atmosphere, where it becomes smog. The atom is then deposited in the forest as nitric acid, which may harm or kill plants and acidifies the soil. Carried to a river, the atom may harm or kill fish and insects and makes its way to the ocean, where it can cause red algae or dead zones, and is ultimately released into the atmosphere as a greenhouse gas that depletes the ozone.
One stumbling block in reducing humanity’s collective nitrogen footprint is that nitrogen fertilization is required to provide enough food for the planet’s population. Minimizing the negative effects of reactive nitrogen and maximizing the benefits of nitrogen in relation to food production are necessary to feed the world and, at the same time, protect the environment.
In an interview with Will Goldsmith (www.c-ville.com), Galloway explains the nitrogen footprint: “My footprint is controlled in part by how much fossil fuel I burn to heat my house, the kind of foods I eat and where they came from, and what I do with my waste.”
Galloway is currently developing a nitrogen footprint calculator so that individuals will be able to calculate the impact of their nitrogen use on the environment.
At the Crop Science Society of America’s recent meeting in Houston, the group’s turfgrass division, C5, gave industry awards to graduate students studying turfgrass science. For the Industry Poster awards, top place went to Elena Sevostianova, New Mexico State University, while Patrick McCullough, Rutgers University, won first place in the Industry Oral awards. Additional winners include: John C. Inguagiato, Rutgers University, in the C5 Oral Competition for Soil/Water; Jacob Richards, University of Arkansas, in the C5 Oral Competition in Physiology, Disease and Ecology; and Jon Trappe, University of Arkansas, in the C5 Poster Competition. For the Turfgrass Breeders Association Awards to students of plant breeding and genetics, Desalegn D. Serba, University of Nebraska, Lincoln, took first place; and Virginia R. Sykes, Virginia Polytechnic Institute, won first place in the Oral Presentation category. |
