From: ARS News Service [mailto:[log in to unmask]]
Sent: Thursday, October 02, 2014 9:16 AM
Subject: Sniffing Out the Source of Beef Manure Odor
ARS News Service
Agricultural Research Service, USDA
--View this report online, plus photos and related stories, at www.ars.usda.gov/is/pr
--Follow us on Twitter at http://twitter.com/USDA_ARS
Sniffing Out the Source of Beef Manure Odor
By Ann Perry
October 1, 2014
A recent study conducted by U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) scientists indicated that just three compounds in beef manure were responsible for generating over two-thirds of detectable odors.
These findings by ARS agricultural engineers Bryan Woodbury and John Gilley could help with developing techniques for controlling objectionable odors from manure used to amend crop fields. ARS is USDA's chief intramural scientific research agency, and this work supports USDA's priority of responding to climate change.
Woodbury and Gilley conducted a comprehensive study to identify compounds responsible for beef manure odor and to evaluate how land application practices, diet, soil moisture and application procedures affect odor emissions. The team used manure collected from feedlot pens where cattle consumed diets containing 0, 10, or 30 percent wet distillers grain solubles. The scientists also evaluated two application methods-no-till surface manure application or disk tillage that incorporated manure into the soil-and collected air samples before and after water was added to the soil to assess the effect of moisture levels on emissions.
Beef cattle manure was applied at levels that provided 135 pounds of nitrogen per acre, which met the 1-year nitrogen requirement for corn. After collecting and analyzing the air samples, the researchers determined that two volatile fatty acids-isovaleric acid and butyric acid-and the aromatic compound 4-methylphenol were responsible for over two-thirds of detectable beef manure odors. Most of these odors were released within 24 hours after manure was applied to the soil.
Incorporating the manure into the soil and irrigating afterwards reduced most of the odor compounds that were measured. But the manure needed to be incorporated almost immediately after being applied to obtain the most effective odor mitigation.
The importance of tilling manure into soil was highlighted by emission measurements the researchers obtained for 4-methylphenol. The greatest emissions of this compound occurred from dry soils on no-till plots and were sometimes as much as 10 times greater than similar emissions from tilled soils.
Woodbury works for the ARS Nutrition and Environmental Management Research Unit < http://www.ars.usda.gov/main/site_main.htm?modecode=54-38-05-80 > in Clay Center, Nebraska, and Gilley works for the ARS Agroecosystem Management Research Unit < http://www.ars.usda.gov/main/site_main.htm?modecode=54-40-10-00 > in Lincoln, Nebraska. They published their research in the Journal of Environmental Quality in 2013.
Read more < http://www.ars.usda.gov/is/AR/archive/oct14/beef1014.htm > about the study in the October 2014 issue of Agricultural Research magazine.
This is one of the news reports that ARS Information distributes to subscribers on weekdays.
Send feedback and questions to the ARS News Service at [log in to unmask]
ARS News Service, Information Staff, Agricultural Research Service
5601 Sunnyside Ave., Room 1-2251, Beltsville MD 20705-5128
[log in to unmask] | www.ars.usda.gov/news
Phone (301) 504-1636 | fax (301) 504-1486
USDA is an equal opportunity provider and employer. To file a complaint of discrimination, write: USDA, Office of the Assistant Secretary for Civil Rights, Office of Adjudication, 1400 Independence Ave., SW, Washington, DC 20250-9410 or call (866) 632-9992 (Toll-free Customer Service), (800) 877-8339 (Local or Federal relay), (866) 377-8642 (Relay voice users).
Enviro-News is a service of the Water Quality
Information Center at the National Agricultural
Library. The center's Web site is at
The Enviro-News list facilitates information exchange.
Inclusion of an item in Enviro-News does not imply
United States Department of Agriculture(USDA) agreement,
nor does USDA attest to the accuracy or completeness of
the item. See
You can contact the list owner at
[log in to unmask]