PT  - JOURNAL ARTICLE
AU  - S. E. Spayd
AU  - R. L. Wample
AU  - R. G. Evans
AU  - R. G. Stevens
AU  - B. J. Seymour
AU  - C. W. Nagel
TI  - Nitrogen Fertilization of White Riesling Grapes in Washington. Must and Wine Composition
AID  - 10.5344/ajev.1994.45.1.34
DP  - 1994 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 34--42
VI  - 45
IP  - 1
4099  - http://www.ajevonline.org/content/45/1/34.short
4100  - http://www.ajevonline.org/content/45/1/34.full
SO  - Am J Enol Vitic.1994 Jan 01; 45
AB  - Nitrogen (N) fertilizer was applied to White Riesling grapevines through the drip irrigation system at rates of 0, 56, 112, or 224 kg N/ha for three years. Attainment of 21% soluble solids was delayed as rate of N fertilization increased. Juice and wine titratable acid and organic acid concentrations did not vary due to N fertilization rate. Juice pH increased linearly with increasing N fertilizer rate and was related to juice titratable acid and ammonia concentration. Juice potassium concentrations were not affected by N fertilizer rate, while wine potassium concentrations increased linearly with increasing N. Wine pH increased with N fertilizer rate and was related to tartrate and to a lesser extent to potassium concentration. Juice total N, ammonia, free amino nitrogen, arginine, and proline concentrations increased linearly with increasing N fertilizer rate. Wine urea concentrations after four to six years of storage at 15°C was low (highest concentration was less than 10 mg/L), but increased linearly with increasing rate of N fertilization.