Research on ammonia and greenhouse gas emissions conducted at Iowa swine farms can be effective in establishing accurate baseline emission rates for similar facilities in the Midwest.
A FIRST-of-its-kind study by Iowa State University scientists is seeking to fill the information gap that exists regarding air emissions from swine facilities.
"Farmers need reliable data to determine if air emissions are above regulatory thresholds and to help make better decisions on where to invest in emission controls," said Hongwei Xin, professor in Iowa State's department of agriculture and biosystems engineering.
However, he added that "research and information on ammonia and greenhouse gas emissions from swine operations — particularly from breeding, gestation and farrowing facilities in the Midwest — have been meager."
Through the study, which was funded in part by the Iowa Pork Producers Assn., Xin and his research team are beginning to fill the information gap.
Since January 2011, his research team has been quantifying ammonia and greenhouse gas emissions from a 4,300-sow breeding, gestation and farrowing facility located in central Iowa. The facility is owned and operated by Iowa Select Farms.
"Establishing air emission values that accurately represent modern, high-tech livestock facilities will be a benefit to all of Iowa's pork producers," Dr. Howard Hill, veterinarian and strategic counsel for Iowa Select Farms, said.
The U.S. Environmental Protection Agency estimates that agriculture (crop and animal production) is responsible for 6.3% of the nation's total greenhouse gas emissions. The greenhouse gases emitted from activities related to animal agriculture include carbon dioxide, methane and nitrous oxide.
"The study is the first of its kind in the nation when it comes to the intensity and duration of monitoring and quantifying the greenhouse gas emissions from swine operations. Our study is much more systematic than previous work (that was) done sporadically using intermittent monitoring of greenhouse gas emissions," Xin said.
Because Iowa leads the nation with more than 17% of the U.S. breeding pig inventory, research on ammonia and greenhouse gas emissions conducted at Iowa farms can be effective in establishing accurate baseline emission rates for similar facilities in the Midwest, according to the news release.
"You have to first know what the baselines are. Then, you can potentially set reduction goals, and if you want to reduce emissions, you need to know where to do it," Xin said.
"What are the hot spots where we can do something about mitigation? In our study, we are looking at the sources of emissions, from the barn to the manure storage area. Different gases may come from different sources. Our study will pinpoint the major sources for certain gases," he added.
Although the study does not include testing technologies that are designed to mitigate emissions, Xin noted that a lot of work has gone into developing mitigation techniques for certain gases. He hopes more work will be done to make those techniques more affordable for producers.
"We have to make sure that producers can employ the technology without driving themselves out of business," Xin said.
The Iowa project concluded monitoring in early June, and final data processing is underway.
Xin said he expects the 29-month-long study to help provide information and implications in areas that include:
* The number of sows that would produce 100 lb. of ammonia per day — a figure that triggers the need for a farm to report ammonia emissions to EPA.
* The benchmark values for ammonia and greenhouse gas emissions from facilities for each production stage: breeding/gestation, farrowing and manure storage.
* Identification of hot spots of different gaseous emissions for potential mitigation. For example, barns may be the primary source of ammonia emissions, while manure storage (both deep pits and outside storage) may be the main source for methane and nitrous oxide emissions.
* The predominant emission may be methane, making up 95% or more of total greenhouse gas emissions from a farm.
"Results of this study will provide a benchmark for the industry, especially in the area of greenhouse gas emissions reporting. We want to know what the numbers are out there," Xin said.