The potential of vegetation to trap NH3 discharged from a layer house through the exhaust fans was evaluated at The Pennsylvania State University Poultry Education and Research Center in September 2005. Five tree species were planted in pot-in-pot containers in 5 rows downwind of the house fans and in 2 control rows upwind of the hen house. Each row included 1 plant (upwind) or 2 plants (downwind) per species per row. When measured with a photoacoustic NH3 detector at the same elevation as the fan (1.5 m), NH3 concentration decreased sharply with greater distance, from 51.54 ppm at 0 m (at the fan) to 1.89 ppm at 5.5 m (between row 2 and 3), 0.27 ppm at 10 m (after row 5), and 0 ppm at 50 m (control). This trend was also observed with the dosi-tubes and photoacoustic detector at the 0.3- and 3.0-m elevations. Significantly lower NH3 concentrations were recorded when the trees were present downwind of the fans compared with when the trees were removed (16.45 vs. 19.35 ppm), suggesting a portion of the atmospheric NH3 was being held by the plants. This was further supported by a marked decrease in foliar N status of the plants with greater distance from the source. Plant species also differed, with willow appearing to be the most responsive species and effective as an NH3 trap.
All Science Journal Classification (ASJC) codes
- Animal Science and Zoology