The Extension Connection
Extension field specialists use scentometers, and their noses, to test for odor near a swine nursery.
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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
The general public doesnt differentiate between odors and
gases, but theres 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
Bryan Bunton, an environmental specialist with the Iowa Department of
Natural Resources (DNR), appreciates Iowa States work on this issue.
Theyre 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 states 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 technologys odor control,
Other technologies being used to successfully control odor included composting
dead swine, used by 50 percent of respondents, and windbreaks, used by
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 Extensions Web site.