Ammonia volatilization from putting greens foliarly-fertilized by conventional or stabilized urea

Low cost, high N-content, and favorable handling characteristics of urea fertilizer (46-0-0) make its use common in turfgrass management. While many investigations confirm incomplete recovery of foliarly-applied urea-N by turfgrass putting greens, the efficacy of urease-inhibiting additives, calcium-maleic-itaconic polymer or N-(n-butyl) thiophosphoric triamide (NBPT), in preventing NH3 volatilization is currently undocumented. Meanwhile, NH3 emissions reduce air and water quality. From 2014 to 2015, NH3 volatilization was measured 0- to 24-hours following foliar application of conventional or stabilized urea fertilizers to ‘Penn G2’ creeping bentgrass (Agrostis stolonifera L.) putting greens at a 20 kg ha–1 N rate in four separate trials. Using a 63% ‘trapping-efficiency’ flux chamber system under the duration and conditions described, 11.1% of conventional or calcium-maleic-itaconic polymer-amended urea-N was lost as NH3. Alternatively, combined amendment by NBPT and dicyandiamide (DC...