Characterization of in-row movement of nitrogen during a rain event and its impact on northeastern Florida potato production

Abstract

Potatoes (Solanum tuberosum L.) in northeastern Florida are produced on sandy soil with low water holding capacity. The objectives of this study were to evaluate the influence of controlled release fertilizer source (N at 196 kg·ha–1) on in-row N movement and to assess the impact of leaching events on ‘Atlantic’ potato production and tuber quality. Drainage lysimeters were installed at a 45-cm depth from the top of the row for leachate collection. The natural and simulate leaching rain events (5 cm in 2 days and in 2 hours, respectively) were applied at 20–25 cm and full-flower potato growth stages, respectively. Polymer sulfur-coated urea (PSCU) treated plants produced the significantly highest total yields (23.9 ton·ha–1). PSCU and polymer coated urea (PCU) treated plants produced similar marketable yields (18.9 and 17.2 ton·ha–1, respectively) compared to plants in AN treatments (16.4 ton·ha–1). Urea formaldehyde (UF) 1 and 2 treated plants produced significantly lower total (17.5 and 17.8 T·ha–1) and marketable (13.7 and 14.0 T·ha–1, respectively) tuber yields than PSCU treated plants. The plots treated with PCU, UF1, and UF2 had significantly lower NO3-N concentrations moving downward than the AN in early season.