Is The “Hot Mix” Too Cold For Controlled-Release Nitrogen Products?
Kent Cushman, Kelly Morgan, Sanjay Shukla, and Monica Ozores-Hampton University of Florida/IFAS Southwest Florida Research & Education Center (SWFREC) Immokalee , FL Eric Simonne University of Florida/IFAS Department of Horticultural Sciences Gainesville , FL Gene McAvoy University of Florida/IFAS Hendry County Extension LaBelle , FL Summary Four nitrogen (N) products were tested at three rates for seepage-irrigated tomato. The products were one soluble source (mostly ammonium nitrate, considered the grower standard) and three controlled-release N (CRN) sources: Nitamin®, Multicote®, and Agrocote®. Rates were 200, 270, and 340 lb/acre N. Product had a profound and significant effect on plant biomass and yield in all size categories. Although leaf N concentrations were at or above sufficiency levels throughout the duration of the experiment in all treatments, ammonium nitrate produced more plant biomass and higher yields than any of the CRN treatments. N rate had little effect on plant
