Microorganisms are present in animal wastewater. These microorganisms may include those important in human and animal disease. Animal wastewater may also contain ammonia and compounds that produce odor. The purpose of this study was to gather baseline information of the types and concentrations of microorganisms and odor compounds in swine lagoon wastewater, in air during swine lagoon wastewater center pivot irrigation, and in cropland soil after center pivot irrigation. This information is critical in identifying or developing safe land application practices. Types of microorganisms were identified and quantified in all sample types. These microorganisms include bacterial indicators (largely nonpathogenic bacteria used as surrogates for pathogen detection) and bacterial pathogens Campylobacter, Arcobacter, and Salmonella. Campylobacter and Arcobacter, were detected in wastewater and soil samples but not in any of the air samples. Salmonella was not detected in any samples. Odor compounds were quantified and identified. Odor compound content in the soil initially increased, but the majority of the compounds were lost within 1 hour after application. Ammonia losses were also quantified. Ammonia-N concentration increased with the application of slurry but declined over the three hours following slurry application. Twenty-four hours after slurry application there was a slight increase in ammonia concentration. This increase is most likely due to lysis of micriobial biomass present in the slurry or decomposition of organic matter in the slurry or soil. Information gained in this study is already being used to develop science-based recommendations for safe land application of animal wastewater.