Swine Manure Odor Reduction Using a Humic Amendment: On-Farm Demonstration

Why Study Odors from Pig Farms?

Odor-related nuisance complaints associated with animal production facilities are on the rise as residential sprawl encroaches on once rural areas. The efficacy of odor control additives is highly variable and most have limited success. This project demonstrated the efficacy of a commercial humic-material product (ManureMaxTM, Manufactured by JDMV Holding, LLC; Huston, TX) for limited control of liquid swine manure odors.

What did we do?

Two similarly-operated, 2,250-pig, tunnel-ventilated finishing barns on one farm were used for the demonstration. Barns were widely-separated by 1,800 feet of woodland and fields and were occupied by pigs of similar age. The underfloor manure storage pit (5-ft deep) of one barn received monthly additions with the additive while the other barn received no additive. After 20 weeks when hogs were finished for market and barns cleaned for restocking, treatments were switched so the previously untreated barn received the amendment. Odors at the barn ventilation exhaust were evaluated monthly by direct sensory methods (olfactometry) using human subjects. Field-applied manure was evaluated at the end of each 20-week grow-out period. Nasal Ranger Field Olfactometer (NRO) units were used to evaluate barn exhaust odor dilutions-to-threshold (D/T) and odors during field application, employing the Multiple-Assessor Repeat Observation (MARO) method (B randt et at., 2011a and 2011b). Barn ventilation exhaust was normalized against fan velocity and compared as odor flux (odor units min-1) among treatments. Whole air samples were collected in 10-liter TedlarTM® bags during each field visit and brought back to the Penn State Odor Assessmnt Laboratory (PSOAL) for evaluation. A team of five qualified odor panelists quantified odor detection threshold (DT) using Dynamic Triangular Forced-Choice Olfactometry (DTFCO) on an Ac’ScentTM International Dynamic Olfactometer (St. Croix Sensory, Lake Elmo, MN) within 10 hours of sample collection.

What have we learned?

Results show a 21% reduction in mean barn odor exhaust as shown in Table 1 and Table 2. The humic amendment significantly decreased barn ventilation odor flux by 21% in both field NRO and laboratory DTFCO evaluations. Evaluation of field applied manure yield a 21% and 60% decrease in odor concentrations for NRO and DTFCO, respectively.mean barn ventilation odor flux

mean barn ventilation odor flux

field-applied manure odor concentration

field-applied manure odor concentration DT


Hile, Michael, Ph. D. Candidate in Agricultural and Biological Engineering (ABE) at Penn State (PSU) mlh144@psu.edu

Brandt, Robin, Senior Lecturer in ABE at PSU, Eileen E. Fabian, Professor in ABE at PSU and Herschel A. Elliott, professor in ABE at PSU. Robert E. Mikesell, Program Coordinator and Senior Lecturer, Department of Animal Science at PSU.

Additional information

Brandt, R.C., H.A. Elliott, M.A.A. Adviento-Borbe, E.F. Wheeler, P.J.A. Kleinman, and D.B. Beegle. 2011a. Field Olfactometry Assessment of Dairy Manure Land Application Methods. J. Environ. Qual. 40: 431-437.

Brandt, R.C., M.A.A. Adviento-Borbe, H.A. Elliott, E.F. Wheeler. 2011. Protocols for Reliable Field Olfactometry Odor Evaluations. J. Appl. Engr Agr. Vol. 27(3): 457-466.

Brandt, R. C., H. A. Elliott, E. E. Fabian, M. L. Hile, R. E. Mikesell, Jr., 2014. Manure Additive Shows Swine Odor Reduction. Fact Sheet. Penn State University, Department of Agricultural and Biological Engineering.


Thanks to JDMV Holding, LLC Houston, TX) for providing funding and product for this project. This project would not have been possible without the support from Natural Resources Conservation Service’ (NRCS) Conservation Innovation Grant (CIG) program.

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