With $1.1M NASA Grant, UMD Researcher to Study Unwelcome Crop: Nitrogen

Whether it comes from a plastic fertilizer bin or the nether end of a cow, nitrogen on farmland can contribute to greenhouse gas emissions. Now, a $1.1 million NASA grant to a team including a University of Maryland researcher will support a study of methods to minimize it.

The project by environmental science and technology Associate Professor Stephanie Yarwood and a multi-institutional team will examine various conservation practices meant to reduce nitrogen emissions related to agriculture.

Knowledge of the real-world effects of those practices on the atmosphere has been limited, in part because the right data hasn’t been available. Compared to metropolitan areas of the country, air quality measurements over rural regions are sparse. But with funding from NASA, Yarwood and her colleagues will fill in the gaps with satellite data to answer questions about how what happens on—and in—the ground on farms affects nitrogen compounds in Earth’s atmosphere.

“It’s interesting for me as a microbial ecologist who often thinks in scales no bigger than a shovel full of soil to be involved in these projects with collaborators that work on much larger scales and think of large, atmospheric effects,” Yarwood said.

Collaborators in the study hail from the University of California, Irvine and the U.S. Department of Agriculture’s Sustainable Agricultural Systems Laboratory.

Farm animal waste and fertilizers are primary contributors of nitrogen to the atmospheric pollutant ammonia and ozone-depleting nitrogen oxides that cause global warming. Using satellite data, the scientists will identify “hot spots” above farmlands and natural areas that have elevated levels of ammonia and nitrogen oxides in the atmosphere, as well as “hot moments”: specific times and conditions in which hot spots occur. The researchers will compare those factors to maps of soil type and other information about the landscapes to select study areas with similar characteristics but different farming practices, which will reveal how farming practices impact nitrogen loss from farms under varying conditions.

An important part of the research where Yarwood’s expertise will come to the fore involves examining the soil microbes in each study area to determine how they are affected by conservation practices, and how the microbial communities influence how much and what kind of nitrogen is released into the air and water.

Ultimately, they intend to develop mathematical models that can predict the movement of nitrogen through agricultural systems based on soil type, landscape, environmental conditions and farming practices.

The models will help policymakers and stakeholders make effective decisions around which climate-smart farming methods will have the largest impact on reducing nitrogen emissions from agriculture. These advances will be important in addressing not only global climate change, but local and regional air quality problems across the U.S. and soil health, among other challenges.

The project will take place over three years, with field assessments expected to begin this winter and spring.