Nitrous Oxide and Ammonia Emissions From Turfgrass: Urea Vs. Polymer Coated Urea.

Nitrogen (N) is generally the most limiting nutrient in soil-based ecosystems, yet is essential for high output crop production and for high-use urban environments. Inherent inefficiencies associated with the uptake and cycling of N result in atmospheric and groundwater pollution. Polymer coated urea (PCU) is a potential solution to these problems. Nitrogen release by PCU meets plant demands in a timely and efficient manner through temperature-controlled N release. Increased crop yields and quality, less labor-intensive fertilization, and reduced nitrate leaching result from its use. In a preliminary study with maize, urea and PCU were applied at varying rates and PCU significantly decreased emissions of both ammonia and nitrous oxide by 46% and 60%, respectively, as compared to equivalent urea treatments. Daily ammonia losses averaged 4.6 and 8.7 mg kg-1 and daily nitrous oxide losses averaged 4.6 and 11.4 mg kg-1 for PCU and urea, respectively. It is hypothesized that this PCU should decrease nitrous oxide (N2O) and ammonia (NH3) emissions from turfgrass as it did with maize. The objective of this study was to compare relative nitrous oxide and ammonia losses in a turfgrass system receiving variable levels of PCU and urea application by using photoacoustic gas analysis and gas chromatography. Increased N-use efficiency would reduce greenhouse gas emissions and nitrate leaching in the high input turfgrass industry. Data are currently being collected and will be reported in November 2010.