Technical Abstract: Swine manure is often applied to crop land as a fertilizer source. Odor emissions from land-applied swine manure may pose a possible nuisance to downwind populations if not applied with sufficient forethought. A research project was conducted to assess the time decay of odorous volatile organic compound (VOC) emissions following land application of swine manure. Three land application methods were compared: surface application, incorporation 24 hours after surface application, and injection. Emission rates were measured in field plots with a small wind tunnel and sorbent tubes. VOCs including eight volatile fatty acids, five aromatics, and two sulfur-containing compounds were quantified by gas chromatography-mass spectrometry. In most cases, a first order exponential decay model adequately described the flux versus time relationship for the 24 hour period following land application, but the model sometimes overestimated flux in the six to 24 hour range. The same model but with the time term squared adequately predicted flux over the entire 24 hour period. Three compounds (4-methylphenol, skatole, and 4-ethylphenol) accounted for 93 percent of the summed odor activity value. First order decay constants (k) for these three compounds ranged from 0.157 to 0.996 hr-1. When compared to surface application, injection of swine manure resulted in 80 to 95 percent lower flux for the most odorous aromatic compounds. These results show that VOC flux decreases rapidly following land application of swine manure, and that four to eight hours are required before the VOC flux returns to background levels.