Effects of Environmental Factors on Odor Emission From Pig Manure

Altering environmental factors may change odor emission from pig manure. The main objective of thislaboratory-scale study was to examine the effects of temperature, ventilation rate, emitting area, and manure dilution ratioon odor emission from growing pig manure, while also testing their effects on manure characteristics. Manure was placedin vessels with different surfaces (303, 475, and 595 cm2), and water was added to create different dilution ratios (0%, 50%,and 100%). The vessels were connected to glass capillaries with different ventilation rates through the headspace (0.5, 1.0,and 1.5 L min-1) and were placed in climate-controlled rooms with different temperatures (10C, 20C, and 30C). We useda face-centered central composite design with 54 experimental units in two rounds of three blocks. Odor samples were takenat the end of experiment (after seven days). Manure samples were collected at the start and at the end of the experiment. Themean odor emission from the manure vessel was 2326 ouE h-1 m-2. Increased temperature, ventilation rate, and dilution ratioincreased odor emission. Emitting area did not influence odor emission, but positively influenced total-N loss. Total-N lossincreased as temperature and ventilation rate increased, but decreased as dilution ratio increased. Lowering temperature andventilation rate can be considered as starting points to reduce odor emission from pig manure in practical conditions. Theeffects of dilution ratio and emitting area on odor emission could not be fully separated from the effect of headspace volumein this study and should be further studied.