Foliar Nitrogen Status and Growth of Plants Exposed to Atmospheric Ammonia (NH3)

Adrizal, P.H. Patterson, R.M. Hulet, and R.M. Bates Department of Poultry Science, and Department of Horticulture, Penn State University, University Park, PA 16802 Abstract Two experiments were conducted to evaluate the potential of plant species to trap NH3 discharged from poultry houses. The four plant species (cedar, locust, poplar, and grass) used in experiment (Exp) 1 and four species (spruce, arborvitae, poplar, and willow) used in Exp 2 were transplanted into 4to 8-L pots and grown in four environmentally controlled chambers. Two of the four chambers received continuous anhydrous NH3 at 4 to 5 ppm (Exp 1) or 6 to 8 ppm (Exp 2) while the other two chambers in each experiment received no NH3. The results of Exp 1 showed that locust was the fastest growing species, supported by its total biomass, root, and root DM weights. There was a trend for all the plants exposed to NH3 to have greater leaf DM than their non-exposed counterparts at 6 (43.0 vs. 30.8%; P=0.09) and 12 wk (47.9 vs. 36.6%; P=0.07), and significantly greater (P≤0.05) leaf N at 6 (6.44 vs. 3.67%) and 12 wk (7.05 vs. 3.51%) when exposed to NH3. An increase in leaf N due to NH3 exposure was also noted in Exp 2 (4.99 vs. 2.83%; P≤0.05), but with no indication with species interaction. Numerically greater leaf DM due to NH3 exposure was consistently measured in poplar tissues at both sampling periods in Exp 1. In Exp 1, poplar, as well as locust and grass, deposited 1.5 to 2 fold greater N in their leaves than cedar tissues as a result of NH3 exposure compared to non-exposed plants. Similar numerical trends in foliar N were also observed in poplar, willow and arbovitae in Exp 2 (P > 0.05). Locust (Exp 1) likely benefited from ambient NH3 while poplar and willow (Exp 1 and 2) were negatively affected by atmospheric NH3.