Nitrogen Fertilization and Growth Stage Affect Silage Quality of Timothy. (C06-belanger887755-poster)
Authors:
G. Belanger* - Agriculture and Agri-Food Canada G.F. Tremblay - Agriculture and Agri-Food Canada R. Drapeau - Agriculture and Agri-Food Canada
Abstract:
The effect of N fertilization on yield is well documented but less research has been conducted on its influence on timothy silage quality. We determined the ensiling properties and silage quality of timothy fertilized with four N rates (0, 60, 120, and 180 kg N/ha) and harvested at four growth stages (stem elongation, early heading, late heading, and early flowering) during spring growth in two years at one site and one year at another site. Forage water soluble carbohydrates (WSC) decreased and the buffering capacity (BC) increased with increasing N fertilization, mostly at the first three growth stages; the ratio WSC/BC also decreased with increasing N fertilization. Forage nitrate concentration increased with increasing N fertilization; this increase tended to be greater at the first two growth stages. Non protein N (NPN) in silage made in laboratory silos increased by 13% with increasing N fertilization at the first three growth stages but decreased by 27% at early flowering. Nitrogen fertilization increased silage pH from 4.4 to 4.8 and ammonia from 41 to 76 g N/kg total N at the first three growth stages. Forage WSC, BC, and the ratio WSC/BC were not correlated with silage pH and ammonia, and were weakly (r = -0.32, 0.33, and -0.34, respectively) correlated with silage NPN. Forage WSC, BC, and their ratio are therefore poor predictors of timothy silage quality.
Speaker Information: Gilles Belanger, Agriculture and Agri-Food Canada, 2560 Hochelaga Boulevard, Sainte-Foy, QC G1V 2J3; Phone: 418-657-7980; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 511)
Keywords: Forage; Timothy; Fertilization; Qualtiy
