Reducing odor emissions using subsurface litter application technology

Manure handling and application to agricultural land from animal facilities can create odor nuisances where population sprawl encroaches into once rural areas. The University of Maryland Eastern Shore (UMES) and The Pennsylvania State University (Penn State) collaborated on a study to quantify the odor reduction benefit of a novel technology called the Subsurfer, which incorporates dry poultry litter below the soil surface as opposed to traditional surface application. Two 25-meter square locations having similar grassy vegetation were chosen at Penn State's Ag Progress Days site. For three separate events, the Subsurfer was used to subsurface and surface apply Turkey litter to the two locations. Odor assessment teams of trained and qualified individuals from UMES and Penn State conducted observations at each location prior to litter application (background odor), and at 1, 4, and 24 hours after the litter was applied at each location. Whole air samples were collected in 10-liter Tedlar™ bags four hours after litter application using surface isolation flux chambers and vacuum suitcases. The samples were analyzed using dynamic forced-choice olfactometry at the Penn State Odor Assessment Laboratory. Results show 89.5% to 95.6% reduction in field D/Twhen litter was incorporated into the soil using the Subsurfer versus surface application with this same technology after 1 hr of application (97.6 to 100% when background odor level was subtracted). Four hours after application, laboratory DT show odor emissions were reduced by 81% (100% less background levels).