Iowa State Unviersity Extension

The Extension Connection

photo of two men using scentometers to test for odor near a swine nursery

Extension field specialists use scentometers, and their noses, to test for odor near a swine nursery.

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Stanley R. Johnson, vice provost for extension,
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Last update: July 2003

A quarterly publication of Iowa State University Extension

Extension sniffs out solutions to air quality issues

For the past several years, neighbors of large hog operations have voiced their concerns about livestock odors and their effects on human health.

“The general public doesn’t differentiate between odors and gases, but there’s a significant difference,” said Jeff Lorimor, an Iowa State University associate professor and extension agricultural engineer. “Gases, specifically ammonia and hydrogen sulfide, do have the potential to pose health concerns when present at high enough concentrations.”

But odors can be a problem for neighbors as well as livestock producers, so Iowa State includes work on odor control in its animal agriculture and air quality program.

ISU researchers and Extension staff have been studying air quality, developing models for siting livestock operations and searching for technologies that can reduce the effects of both odors and gases on air quality near livestock production facilities so they do not adversely affect their neighbors.

Bryan Bunton, an environmental specialist with the Iowa Department of Natural Resources (DNR), appreciates Iowa State’s work on this issue. “They’re on top of things,” he said. “Iowa State has one of the top programs in air quality research.”

One ISU Extension project involved a survey of the state’s pork producers on their satisfaction with various technologies for controlling odor from livestock manure, Lorimor said. More than 500 producers participated in the 2002 survey, funded by the Iowa Pork Producers Association and the Iowa Agriculture and Home Economics Experiment Station.

“The purpose was to establish a benchmark for what people are doing,” Lorimor said. “Seventy percent of producers are injecting manure (into the soil). Soil injection clearly is a well-accepted and successful odor control technique.”

Seventy-seven percent of the producers were using “deep pits” — manure storage areas underneath their livestock facilities — and three fourths were satisfied with that technology’s odor control, Lorimor added.

Other technologies being used to successfully control odor included composting dead swine, used by 50 percent of respondents, and windbreaks, used by 38 percent.

In addition, producers have used a variety of other technologies as methods to minimize odors, such as bio- and plastic covers on their pits, aeration and pit additives.

To learn more about air quality issues, check ISU Extension’s Web site.