Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Fluid Journal 2002-2004
Spring 2002 Dr. C. F. Mancino, Ms. Dianne Petrunak, and Mr. Douglas Wilkinson Liquid N Shines in Turf Applications Granular fertilizers are routinely used in golf course putting green establishment and maintenance. Smaller particle-size grades have been developed in order to improve the uniformity of the fertilizer application and to aid in mowing the fertilizer into the turf canopy. Typi- cally, greens-grade granules are between 0.5 and 1.4 mm in diameter with a small percentage of the fertilizer <0.5 mm and >1.4 mm. However, despite their small size, it is often observed that fertilizer granules remain on the turf canopy surface after application and that some fertilizer is removed along with turf Editor's note: This article has been adapted for the Fluid Journal from a research paper on golf course turf management. Though there are mostly granular trials in the discus- sion, the article has been tailored to focus on a portion comparing granular and fluid nitrogen losses in putting green turf management. Summary: N loss with granular nitrogen fertilizers was greatest in the first and second mowings. Total percentages of N losses from granular fertilizers were: IBDU 31-0-0 (75.4%), Polyon 42-0-0 (70.8%), Milorganite 6-2-0 (55.7%), Nutralene 40-0-0 (47%), UHS Signature 15-0-30 (19.3%), and Isotek 11-3-22 (9.5%). Liquid N fertilizer (N-Sure Pro 30-0-0) showed a dramatic increase in N efficiency with only a 1.9 percent N loss when compared to these granulars. N loss appeared to be most related to water solubility of the fertilizer. Size and density also may have been factors. clippings during mowing. General recommendations made to reduce mowing loss of granular fertilizers include 1) irrigation, 2) application of the fertilizer just after mowing, 3) skipping of mowing the day after fertilizer application, 4) mowing without baskets, and 5) spiking the green prior to fertilization. The objective of this study was to determine the amounts of various greens- grade fertilizer that were lost along with clippings during routine putting green mowing. Materials and methods Location. Joseph Valentine Turfgrass Research Facility at Penn State Univer- sity. Study site. The studies were conducted on a sand-based, established 'Pennlinks' creeping bentgrass putting green. Fertilizers. The N fertilizers used in this study are shown in Table 1. Each fertilizer is recommended for use on putting greens and other low-cut turf. Three 200-g samples of each granular fertilizer were sieved for particle size analysis. The uniformity coefficient and Blake's fineness modulus of each fertilizer were determined as specified by the U.S. Golf Association for a sand topdressing. This was done in order to compare the size characteristics of the granular fertilizer with those of accept- able topdressing sand that would be expected to fall down into the putting green turf canopy. All of the granular N fertilizers had acceptable uniformity coefficients with Isotek and IBDU being most uniform (Table 1). Liquid N fertilizer Table 1. Sieve analysis, uniformity coefficient, fineness modulus and water solubility of greens-grade N-containing granular fertilizers. N-Sure Pro is a liquid N source. N Sieve size (mm) WS %<0.50.51.01.42.02.8UCFM% % retained Polyon 41 2.4 50.8 42.8 5.2 0.0 0.0 1.66 3.10 0.0 Milorganite 6 1.2 58.8 39.6 0.0 0.0 0.0 1.72 2.95 6.0 IBDU 31 1.2 79.2 19.2 0.0 0.0 0.0 1.55 2.89 4.0 Nutralene 40 1.2 58.0 40.4 0.0 0.0 0.0 1.81 2.99 32.0 UHS Signature 15 5.6 65.2 26.8 1.6 0.0 0.0 1.80 2.87 50.0 Isotek 11 0.4 9.6 36.8 46.0 7.2 0.0 1.45 3.72 66.0 N-Sure Pro 30--- --- --- --- --- --- --- --- --- __________________________________________________________________________ UC = Uniformity coefficient FM = Fineness modulus WS = Water solubility Shows less N loss compared to granulars in 1999 Penn State University putting green trials.
Fluid Journal 1999-2001
Fluid Journal 2005-2007