Improved Nitrogen Management for Burley Tobacco Production in the United States

Abstract

Burley tobacco (Nicotiana tabacumL.) has historically been fertilized with nitrogen rates ranging from 150 to 250 kg N/ha. The objectives of the this study were to: (i) evaluate the response of burley tobacco to N fertilization; (ii) determine if split N applications increase burley tobacco yields; and (iii) evaluate a modified pre-sidedress soil nitrate test (PSNT) as a tool for N management in burley tobacco. Nitrogen rates included: 0, 67, 135, 202, and 270 kg N/ha preplant in combination with 0 and 67 kg/ha N sidedress. In 2008, the 270 kg N/ha rate was dropped and the variety TN 90LC was added to the study. Modified pre-sidedress nitrate test (PSNT) samples were taken to a depth of 15 cm prior to sidedress N applications. Analysis of variance was used to analyze burley tobacco yield response to preplant and sidedress N applications and polynomial regression was used to analyze PSNT levels and preplant N rates. Optimal yields were reached with 135 kg N/ha. Pre-sidedress nitrate test levels in 2008 predicted yields more precisely than in 2007 due to higher precipitation at experimental sites. The information from the study indicates that burley tobacco yields were maintained at lower N rates than traditional N applications rates.