Webinar – Fate of Foliar Nitrogen Applied to Golf Course Systems as Influenced by Petroleum-Derived Spray Oil
Webinar begins at 12:20PM on Friday! Zoom password is 017092.
Ammonia volatilization of foliarly-applied nitrogen (N) fertilizer to golf course systems is deleterious to both the environment and the original agronomic objective. Current best management practices have been shown to mitigate this loss, but circumstances specific to putting green and fairway management often preclude their implementation. The objective of this MS thesis research is to quantify how foliar application of commercially available petroleum-derived spray oil (PDSO) and/or urea-based N fertilizer influences vigor, canopy quality, fertilizer-N recovery by, and 0- to 24-hour fertilizer-N ammonia loss from creeping bentgrass (Agrostis stolonifera L.) putting greens and fairways. To quantify vigor and fertilizer-N recovery, clipping yields were taken in June, July, and August of each study year. Closed-flux chambers were installed immediately following treatment applications in July and September to quantify 0- to 24-hour fertilizer-N ammonia loss. Finally, semi-weekly canopy reflectance data was collected using a passive multispectral radiometer and used to calculate the resolute dark green color index (DGCI). In 2019, putting green data showed increased creeping bentgrass vigor when urea-N sources were applied in combination with PDSO, compared to being applied alone. Similarly, plots treated with urea-N in combination with PDSO demonstrated increased fertilizer-N recovery. Fertilizer-N ammonia loss 0- to 24-hours following application ranged from 1 to 5% but was dependent on urea-N source. Finally, plots treated with urea-N in combination with PDSO displayed significantly higher DGCI values when pooled across urea-N sources. Results from the fairway study will also be presented.