Nitrogen Source and Rate Effects on Velvet Bentgrass Putting Green Turf

• Published in: Crop science 2011, Vol.51 (1), p.342-352
• Main Authors: Pease, Benjamin W, Koeritz, Eric J, Soldat, Douglas J, Stier, John C
• Format: Article
• Language: English
• Subjects: acid soils; Acidic soils; acidifying fertilizers; Acidity; agronomic traits; Agronomy. Soil science and plant productions; Agrostis canina; Alkaline soils; Ammonium; Ammonium nitrate; ammonium sulfate; ball roll distances; Biological and medical sciences; Calcium; calcium nitrate; chlorophyll; Cultivars; dry matter accumulation; fertilizer rates; Fertilizers; Fundamental and applied biological sciences. Psychology; golf courses; Grasses; Life sciences; Nitrates; Nitrogen; nitrogen fertilizers; Peat; plant density; playability characteristics; putting greens; Sand; Silt loam; silt loam soils; Soil fertility; Soil pH; Soils; Turf; turf grasses; turf management; turf quality; Turfgrasses; Urea
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci2010.05.0246

Nitrogen source and rate effects on velvet bentgrass (Agrostis canina L.; VBG) putting greens are not well documented, particularly in the north central United States which has different conditions than areas where VBG is normally grown. Acidic soil pH is perceived as necessary for VBG; in nonacidic soils, acidifying fertilizers may provide better VBG quality than less or nonacidic fertilizers. We wanted to determine the effects of N sources representing a range of acidity and N rates (49, 146, 244 kg ha−1 yr−1) on VBG agronomic and playability characteristics when grown on alkaline soils. Fertilizer treatments were applied at 2-wk intervals to ‘Vesper’ VBG putting greens using liquid forms of ammonium sulfate, urea, ammonium nitrate, and calcium nitrate. Separate trials were conducted on two root zones: an 80:20 sand/peat mixture (pH 7.8) and a Troxel silt loam (pH 7.0). Nitrogen source usually had negligible effects on turf characteristics, though occasionally calcium nitrate resulted in poorer quality or shoot density than other sources. Clipping yield, shoot density, and relative chlorophyll index increased, and ball roll distances decreased, as N rate increased. On sand, not even the 244 kg ha−1 yr−1 rate of N guaranteed acceptable turf quality. On silt loam, 146 kg ha−1 N yr−1 usually provided acceptable turf quality, though quality was occasionally improved at 244 kg ha−1 N yr−1 Velvet bentgrass suffered from mid-summer stress alleviated by higher rather than lower quantities of N fertilizer.