Core Ideas: Specific circumstances may limit use of all existing turfgrass best management practices. Urea fertilizer amended by biological inhibitors was foliarly applied to turfgrass. Flux chambers were used to measure NH3 volatilization over 24 hours. Addition of NBPT+DCD to aqueous urea significantly inhibited NH3 volatilization. Commercial or on-site NBPT+DCD amendment of urea reduced NH3-N loss by 6.5 to 7.3%. 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. Furthermore, NH3 emissions reduce air and water quality. From 2014 to 2015, NH3 volatilization was measured 0 to 24 h 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 (DCD) prevented 1.3 to 1.4 kg ha−1 NH3–N emissions, reducing volatilization loss to only 3.8 to 4.6% of the foliarly applied urea-N.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science
- Soil Science
- Management, Monitoring, Policy and Law