Effect of Nitrogen Application Timing on N Uptake by Vitis labrusca in a Short-Season Region

摘要: Fertilizer nitrogen (N) was applied to Vitis labrusca L. cvs. Niagara and Concord grapevines in Michigan at various times determine its effect on soil N levels fertilizer recovery vine tissues. Labeled ammonium nitrate (15NH415NO3) the beneath vines a rate of 68 kg N/ha different between budbreak six weeks after bloom. Soil sampled one-to two-week intervals applications follow inorganic dynamics. Vines were excavated time commercial grape harvest quantify recovery. All application resulted less than 20% uptake applied. fertilized generally contained allocated greater fraction fruit leaves later application. season absorbed more it total roots earlier Later remaining top 90 cm end season. Based these findings, vineyards this short-season region efficient bloom budbreak. Acknowledgments: The authors wish thank Agricultural Experiment Station Project GREEEN for support work.