Influence of Nitrogen Rate and Form on Quality of Putting Greens Cohabited by Creeping Bentgrass and Annual Bluegrass

Abstract

Of the essential nutrients, N fertility generally influences golf course putting green (PG) quality and growth rate most significantly. Despite considerable field research on N fertility of PGs, results interpretation and transfer to practice is complicated by various influential factors; including unrepresentative mowing heights and/or frequency, varying irrigation water quality, undeclared composition of mixed swards, withdrawn cultivars, and/or use of temperature-dependent organic fertilizer sources. A 2-yr field study was initiated in 2003 at University Park, PA, to evaluate the influence of soluble N fertilizer source and rate on qualitative and nutritional parameters of a mature, primarily surface-drained, "push-up" PG cohabited by 'Penn A4' creeping bentgrass (Agrostis palustris Huds.) and annual bluegrass (Poa annua L.). Using an array of soluble N form quotients (NH 4-N/ NO 3-N), split applications of annual N fertilizer rates ranging from 69 to 402 kg ha 21 were sprayed every 15 6 4 d, April to October. Putting green growth, color, N uptake (NUP), and leaf N, K, Ca, Mn, Cu, and Zn increased directly with N rate, while plots receiving N rates in excess of 244 kg ha 21 yr 21 demonstrated acceptable PG quality and tissue nutrient concentrations. However, N rates .244 kg ha 21 yr 21 containing .50% NH 4-N significantly enhanced shoot growth, color, NUP, leaf Mn, P, and Mg levels, when compared to equal rates containing $50% NO 3-N. Frequent fertilization with NH 4-N at annual rates .244 kg ha 21 maximized canopy color and most tissue nutrient levels of a mature creeping bentgrass/annual bluegrass cohabited PG growing on a neutral, fine-textured soil.

Nitrogen Source and Rate Effects on Velvet Bentgrass Putting Green Turf

“…Potter et al (1985) found routine applications of ammonium nitrate fertilizer over 7 yr signifi cantly reduced the pH of a silt loam. Schlossberg and Schmidt (2007) found that N treatments containing >50% ammoniacal N significantly increased growth, color, N uptake, and leaf nutrient levels compared to equal treatments containing >50% nitrate N sources. The silt loam root zone would have been less likely to show a pH change than the sand root zone due to inherent buff ering capacity.…”

“…Given the relatively short time period (2.5 yr) of the study, it is possible that long-term use of calcium nitrate could have more consistent, negative results on VBG turf than we noticed. Schlossberg and Schmidt (2007) found that N treatments containing >50% ammoniacal N significantly increased growth, color, N uptake, and leaf nutrient levels compared to equal treatments containing >50% nitrate N sources. Their demonstration of ammoniacal N sources yielding better turf conditions than nitrate N sources agrees with our fi ndings that ammonium sulfate and ammonium nitrate occasionally produced better turf than calcium nitrate.…”

Microbial and soil properties in bentgrass putting greens: Impacts of nitrogen fertilization rates

“…Although putting greens occupy only a small area of a golf course, they consume a disproportionate amount of resources, especially fertilizers (Schlossberg and Schmidt, 2007). Intensive N fertilization is essential for supporting and maintaining putting green quality including color, vigor, root-to-shoot ratio, and disease resistance (Turgeon, 1999).…”

Long‐term Effects of Nitrogen and Potassium Fertilization on Perennial Ryegrass Turf

“…Clipping yield and tissue K increased with N rate (49-441 kg N ha −1 yr −1 ), whereas soil K and soil pH decreased with N rate (Table 3). The increase in tissue K with N observed in turf and forage grasses is largely due to the increased shoot growth demand with increasing N (Hojjati et al, 1977;George et al, 1979;Snyder and Cisar, 2000;Fitzpatrick and Guillard, 2004;Petrovic et al, 2005;Schlossberg and Schmidt, 2007) with a corresponding decrease in soil K (George et al, 1979;Fitzpatrick and Guillard, 2004). The decrease in soil K may also be due to increased leaching loss with increased N rate.…”

“…Specifically, approximately 97, 68, 99, and 90% of the N effect was linear for CY, tissue K, soil K, and soil pH, respectively (Table 2). The increase in tissue K with N observed in turf and forage grasses is largely due to the increased shoot growth demand with increasing N (Hojjati et al, 1977;George et al, 1979;Snyder and Cisar, 2000;Fitzpatrick and Guillard, 2004;Petrovic et al, 2005;Schlossberg and Schmidt, 2007) with a corresponding decrease in soil K (George et al, 1979;Fitzpatrick and Guillard, 2004). The increase in tissue K with N observed in turf and forage grasses is largely due to the increased shoot growth demand with increasing N (Hojjati et al, 1977;George et al, 1979;Snyder and Cisar, 2000;Fitzpatrick and Guillard, 2004;Petrovic et al, 2005;Schlossberg and Schmidt, 2007) with a corresponding decrease in soil K (George et al, 1979;Fitzpatrick and Guillard, 2004).…”