Cattle feedlots are a significant source of atmospheric ammonia in the United States, but a team of Kansas State University researchers is working on ways to help producers reduce those emissions.
Ammonia reacts with acid in the air, forming particles that can result in regional haze and more importantly, the deposition of nitrogen both locally and in distant areas, says Jay Ham, an agronomist with K-State Research and Extension. Nitrogen deposition can affect rivers and lakes, and alter vegetation in native ecosystems.
To measure the extent of ammonia emissions from feedlots, Ham and his research team in environmental physics have designed a new system specifically for this purpose.
"Over the past three years, we've designed and tested a Relaxed Eddy Accumulation (REA) System to measure nitrogen-compound emissions from cattle feedlots and other strong nitrogen sources," Ham says.
The system consists of numerous sensors on a tower built near a feedlot.
"The objective," Ham says, "is to learn about where the nitrogen is located within a feedlot system, and where it is transported. Statistics show that about 30-40% percent of all feed nitrogen delivered to a pen is ultimately lost to the air as ammonia. We want to know exactly how much ends up in the air, and if those levels have any impact on the environment."
The U.S. Environmental Protection Agency does not have Kansas-based data on ammonia emissions from feedlots.
"Through our research, we hope to deliver solid scientific information to producers and regulators. The data collected over the past few years is currently being analyzed and documented. The ultimate goal is to develop management systems that keep ammonia emissions to a minimum," Ham says.