Author
![]() |
ZHU, QING - Chinese Academy Of Sciences |
![]() |
SCHLOSSBERG, MAXIM - Pennsylvania State University |
![]() |
Bryant, Ray |
![]() |
SCHMIDT, JOHN - Pioneer Hi-Bred, Inc |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/1/2012 Publication Date: 8/31/2012 Citation: Zhu, Q., Schlossberg, M.J., Bryant, R.B., Schmidt, J.P. 2012. Creeping bentgrass putting green response to foliar nitrogen fertilization. Agronomy Journal. 104:1589-1594. Interpretive Summary: The objective of this study was to identify Penn A-1/A-4 creeping bentgrass putting green quality and growth response to rate, type, and/or timing of foliarly-applied nitrogen (N) fertilizer. Plots were mowed two to five days per week; clipping yield was measured; and triplicate measures of canopy reflectance were recorded as measures of turfgrass quality and density. Single application of Amine at N rate of 37 kg ha** -1 had similar (or even slightly higher) canopy reflectance as those treated with ammonium nitrate at higher N rate and also had similar cumulative N uptake as the treatments with higher N rates. In addition, since it had less N input than the other treatments with higher N rates, it also had better N use efficiency and thus may have less N loss to the environment. Technical Abstract: ABSTRACT In 2009 and 2010, three independent fertility trials were conducted on a putting green (PG) managed within the Pennsylvania State University Joseph Valentine Turfgrass Research Center (University Park, PA). The objective was to identify Penn A-1/A-4 creeping bentgrass putting green quality and growth response to rate, type, and/or timing of foliarly-applied nitrogen (N) fertilizer. Fertility treatments were prepared using a soluble ‘Amine’ 15–0–7 liquid fertilizer (13.7% stabilized-NH2, 1.3% NO3–N) containing 0.17% patented Speedo chemistry (Plant Impact Inc., Preston, UK), or a ‘Salt’ 15–0–7 liquid fertilizer (8.5% NO3–N, 6.5% NH4–N) formulated using KNO3 and NH4NO3. Amine or Salt fertilizer was applied to deliver 24.5, 37, or 49 kg N ha** –1 in 815 L ha** –1 spray volume. Two to five days per week following the first clipping yield collection, triplicate measures of 660– and 850–nm canopy reflectance were recorded after mowing. Reflectance data were used to calculate the normalized differential vegetative index (NDVI) and the dark green color index (DGCI), measures of turfgrass quality and density. In all three experiments, single application of Amine at N rate of 37 kg ha** -1 had similar (or even slightly higher) NDVI and DGCI as those treated with salt at higher N rate. The single application of 37 kg ha** -1 Amine had similar cumulative N uptake as the other treatments with higher N rates. In addition, since it had less N input than the other treatments with higher N rates, it also had better N use efficiency and thus may have less N loss. |