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Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/5/2010 Publication Date: 1/1/2011 Citation: Miles, D.M., Brooks, J.P., Sistani, K.R. 2011. Spatial contrasts of seasonal and intraflock broiler litter trace gas emissions, physical and chemical properties. Journal of Environmental Quality. 40:176-187. Interpretive Summary: Comprehensive mitigation strategies for gaseous emissions from broiler operations require knowledge of litter physical and chemical properties, gas evolution, bird effects as well as broiler house management and type of structure. This research estimated broiler litter surface gas flux for ammonia, nitrous oxide and carbon dioxide, concurrently measured litter temperature, and determined litter total nitrogen, ammonium, total carbon content, moisture and pH. Color plots illustrate the spatial nature of parameter changes within each flock and between seasons. Overall trends for gas flux indicate an increase in magnitude with bird age during a flock for both summer and winter, but flux estimates were reduced in areas where heavy cake formed (between feeders/waterers and in the fan area) at the end of the flocks. The reported relationships among measured parameters, house management and structure provide a resource to the poultry industry and researchers for creating new management strategies for controlling gas emissions. Technical Abstract: Comprehensive mitigation strategies for gaseous emissions from broiler operations require knowledge of litter physical and chemical properties, gas evolution, bird effects as well as broiler house management and type of structure. This research estimated broiler litter surface gas flux for ammonia (NH3), nitrous oxide (N2O) and carbon dioxide (CO2), concurrently measured litter temperature, and determined litter total nitrogen (N), ammonium (NH4+), total carbon (C) content, moisture and pH. Grid sampling was imposed over the floor area of two commercial broiler houses at the beginning (day 1), middle (day 23), and end (day 43) of a winter (flock 15) and a subsequent summer flock (17) on reused pine shavings litter. The grid was comprised of 36 points, 3 locations across the width and 12 locations down the length of the houses. To observe feeder and waterer (F/W) influences on the parameters, eight additional sample locations were added in a crisscross pattern between these automated supply lines. Color variograms illustrate the nature of parameter changes within each flock and between seasons. Overall trends for gas flux indicate an increase in magnitude with bird age during a flock for both summer and winter, but flux estimates were reduced in areas where heavy cake formed (at F/W locations and in the fan area) at the end of the flocks. End of flock flux from pooling all samples estimated 1040 mg NH3 m-2 h-1, 20 mg N2O m-2 h-1, and 24,200 mg CO2 m-2 h-1 in winter and 843 mg NH3 m-2 h-1, 18 mg N2O m-2 h-1, and 27,200 mg CO2 m-2 h-1 in summer. The reported relationships among measured parameters, house management and structure offer a resource to the poultry industry and researchers for creating new management strategies for controlling gas evolution. |
