Evaluation of Nitrogen Gas Loss from Polymer Coated and Polymer Sulfur Coated Urea.

Previous research showed less than expected slow and control release properties from polymer coated (PCU) and polymer sulfur coated urea (PSCU) when applied on turfgrass. To further verify and quantify nitrogen (N) loss, experiments were conducted that measured N gas emissions. Prills were surface applied in a semi enclosed system, with soil moisture kept at field capacity. Nitrous oxide (N₂O) and ammonia (NH₃) emissions were continuously measured every 20 minutes using photo acoustic infrared spectroscopy for a period of 45 days. Nitrous oxide emissions from PSCU indicated limited slow release of N with values equal to uncoated urea but 1.2 and 2.3  times higher than PCU and control, respectfully. Whereas PCU resulted in 1.2 and 1.59 less N₂O emissions compared to PSCU and uncoated urea. Similar results were seen with NH₃ readings for PSCU, while PCU showed no increase of NH₃ over an unfertilized control. Indicating that PCU’s controlled release of N reduces volatilization under high soil moisture, whereas PSCU does not.