Selected Current ISU Livestock Odor and Air Quality Research and Extension

July 2014

Air Management Practices Assessment Tool. AMPAT is an online resource that provides an objective overview of mitigation practices best suited to address odor, emissions and dust at Iowa livestock operations. AMPAT helps producers compare and narrow their options of the best mitigation techniques for animal housing, manure storage and handling and land application of manure. The tool provides conservative estimates of the effectiveness of mitigation plus the relative cost. It was originally developed in 2004.

  • Phase 1: Funded by the National Pork Board, this project is updating the current site to include more recent mitigation techniques and to add impacts on volatile organic compounds and greenhouse gases. A new interface for easier side-by-side comparisons are included. Short video presentations and fact sheets are available for each technology. The project is nearing completion. (Jay Harmon, Steve Hoff, Agricultural & Biosystems Engineering; Angie Rieck-Hinz, Agronomy)
  • Phase 2: Funded by the Indiana Soybean Alliance, this project will provide a comprehensive literature database for all major livestock and poultry species. This data will be available for researchers and others wanting to examine mitigation techniques at a deeper level. Results will be used to update and improve the AMPAT tool as new information emerges. (Jacek Koziel, Jay Harmon, Steve Hoff, Agricultural & Biosystems Engineering; Angie Rieck-Hinz, Agronomy)

Evaluation of polymer to reduce emissions from swine finishing facilities. ISU scientists will conduct research to evaluate the efficacy of an acidic polymer from a private firm to potentially reduce ammonia, greenhouse gas and odor emissions from deep-pit swine manure storage areas. The project, which begins in summer 2014, will initially be a lab study under controlled conditions using manures of different sources and distinct dosing rates. Options for field-testing will be reviewed based on results of the study. (Daniel Andersen, Jacek Koziel, Agricultural & Biosystems Engineering)

Estimating methane emissions. ISU researchers developed a lab procedure to estimate manure’s methane production rate and used field-measured variables to estimate methane emission from swine manure storage areas. They continue to work on methods to characterize manure’s physical, chemical and biological properties and relate them to the methane production rate. The research is important to better understand and estimate the production and emission of this potent greenhouse gas from manure storage. (Daniel Andersen, Agricultural & Biosystems Engineering)

Chimney use for odor at a swine facility.

Anaerobic digestion’s impact on odor, ammonia. ISU scientists are studying anaerobic digestion and energy generation from manure and how these processes may influence odor and ammonia emissions. They will evaluate how anaerobic digestion influences odor and ammonia during storage after digestion and undigested manure. They will evaluate physical properties including solids content, particle size distribution and viscosity as well as chemical properties including pH, ammonia nitrogen content, chemical oxygen demand and volatiles solids. They will seek to relate these properties to the potential for ammonia and odor emission. The research begins the summer of 2014 and will run two years, with a Fulbright Scholar recruited for the project. (Daniel Andersen, Jacek Koziel, Agricultural & Biosystems Engineering)

Diets that reduce ammonia emissions from hen houses. Results from ISU research indicate that manipulating the diets of laying hens is a viable means of reducing ammonia emissions. The two-year field study involving commercial laying-hen houses in Iowa examined the effects of adding to diets a commercial feed additive called EcoCal or dried distillers grains with solubles (DDGS). The feed additive diet reduced ammonia emissions by an average of 39 percent; the DDGS diet reduced emissions by 14 percent. In both cases, the diets had no negative effects on hen production performance as compared to the control diet. The project is funded by the USDA Natural Resource Conservation Service’s Conservation innovation Grant Program and the United Egg Producers. (Hongwei Xin and Hong Li, Agricultural & Biosystems Engineering)

Environmental assessment of laying-hen housing systems. ISU scientists are studying indoor air quality and gas and particulate emissions as part of a national project that is systematically assessing three different laying-hen housing systems. Data from the study provide baseline comparisons and emission values for conventional and alternative hen housing systems. The project is funded by the Coalition for Sustainable Egg Supply. (Hongwei Xin, Tim Shepherd and Yang Zhao, Agricultural & Biosystems Engineering)

Quantifying emissions from swine facilities. A first-of-its-kind study by Iowa State is seeking to fill the information gap that exists on air emissions from swine facilities. Research and information on ammonia and greenhouse gas emissions from swine operations — particularly from breeding, gestation and farrowing facilities in the Midwest — has been meager. A research team has been quantifying ammonia and greenhouse gas emissions from a 4,300-sow breeding, gestation and farrowing facility located in central Iowa. The research contributes to establishing accurate baseline emission rates for similar facilities in the Midwest and provide farmers with reliable data in making decisions on emission controls. The project is funded by the Iowa Pork Producers Association and administered by the National Pork Board. (Hongwei Xin, Robert Burns and John Stinn, Agricultural & Biosystems Engineering)

Community Assessment Model (CAM) for Odor Dispersion. Since 2005, CAM has been a valuable preplanning tool offering guidance for hundreds of Iowa pork producers on where to build new facilities. The field-validated computer model helps assess potential site risk and determine how far odors from proposed sites will travel under a variety of atmospheric conditions. The model makes predictions based on historic weather patterns, type and size of facility and number of animals. CAM notes location of neighbors, other odor sources, number and age of animals, seasonal ventilation rates and more. The model estimates what percentage of time a neighbor may be exposed to odors. It factors in how odor-reduction technologies would benefit sites. ISU’s Iowa Pork Industry Center and the Coalition to Support Farmers have partnered to advise farmers on selecting sites, including using CAM as a resource. Three papers on CAM’s acceptance as a useful tool and evaluating its effectiveness have been published. (Steve Hoff and Jay Harmon, Agricultural & Biosystems Engineering)

Biofilter use at a swine facility.

Biofilters conference and educational modules. Biofilters can be an effective means to reduce odor and other gas emissions from ventilated animal and manure storage facilities. Iowa State will host a biofilter conference on Aug. 20, 2014, at the Scheman Building on campus, to introduce producers, managers and owners to biofilters and how they may be used to mitigate emissions from animal feeding operations. The conference will outline factors such as costs, effectiveness, management and other details, and provide sources of science-based information on biofilters. ISU also is developing two educational modules on the use and construction of biofilters. The ready-made modules will make it more convenient for producers to consider biofilters, and will be complete with instructions, bill of materials, construction procedures and on-farm implementation. There also will be online videos on the process. The project is expected to be completed by late summer 2014. (Steve Hoff and Jay Harmon, Agricultural & Biosystems Engineering)

Soybean-hull manure additive. Iowa State researchers conducted farm-scale testing of soybean peroxidase, a compound derived from soybean hulls for swine manure treatment and mitigation of key odor-causing gases, ammonia, hydrogen sulfide and greenhouse gas emissions. The researchers applied the ground soybean hulls-based product treatment through floor slats of swine housing. Over a month and a half, the treatment reduced ammonia by 22 percent, hydrogen sulfide by 80 percent and key odor-causing compounds from 14 percent to 48 percent. The estimated cost of treatment was $1.45 per marketed pig and $2.62 per marketed pig when the cost of labor was added, placing it at the lower range of comparable products. The project, funded by the National Pork Board, was completed in June 2014. (Jacek Koziel, Agricultural & Biosystems Engineering)

Extension manure applicator training. ISU organizes and delivers the annual Iowa Manure Applicator Certification program, a state-mandated training for confinement site and commercial manure applicators. The Iowa Department of Natural Resources contracts the program to ISU Extension. About 4,800 people were certified in the past year, with ISU faculty and extension specialists conducting workshops on regulatory requirements and odor control management practices. During the 2014 commercial applicators training, a module was presented on land application methods to conserve nutrients and minimize odor. The module discussed the impact of timing and weather conditions and achieving optimal injection and incorporation. A follow-up session is under development for 2015 to demonstrate how to adjust manure application equipment to achieve better incorporation and injection. (Daniel Andersen, Agricultural & Biosystems Engineering)

Extension fact sheets on odor and manure. A set of new or revised extension fact sheets are under development and will cover topics that include: acidification, aeration, anaerobic digestion, composting, impermeable covers, permeable covers, manure additives, segregation of manure solids and liquids, and solids separation. (Daniel Andersen, Agricultural & Biosystems Engineering)