48th TWC, Tob. Work. Conf., 2018, abstr. 05

Performance of alternative nitrogen source/fertility programs for Burley tobacco in Maryland

University of Maryland, Leonardtown MD USA

In Maryland, the availability and handling requirements of many traditional nitrogen and potassium sources, such as ammonium nitrate and potassium nitrate is limited, increasing their cost and reducing their practicality of use. Fertilizer distributors have turned to alternative fertilizer blends in their tobacco fertilizer programs. In addition, many farmers continue to utilize alternative fertility regimes, often with programs utilizing less than the recommended nutrient amounts. A field trial evaluating eight different fertility programs for burley tobacco was conducted during the 2017 growing season in a field comprised of Evesboro loamy sand coastal plain soil. Tobacco variety KY 14-L8LC was planted on May 19 on 38 inch wide rows with 22 inch in-row spacing. Rainfall for the year was very high, with 20.8 inches of rain/irrigation received during the growing season. One rainfall of 5.5 inches occurred July 3rd with high leaching potential. The trial utilized a randomized complete block design with four replications. Tobacco was stripped to three positions and graded with a total value and net value calculated based on grade, yield, and market price per grade and fertilizer cost per treatment. The standard treatment (240N-60P-180K) which utilized ammonium nitrate in the nitrogen program and the sulfur based treatment (240N-60P-180K) which utilized ammonium sulfate in the nitrogen program yielded the highest with 2639 and 2610 pounds/acre respectively. There was no significant difference between the first six treatments, however the foliar treatment (122N-64P-124K) and the urea ammonium nitrate liquid treatment (132N-64P-124K) yielded significantly less. Net dollars per acre (gross income minus fertilizer cost) was highest for the standard treatment at $4,958.53 per acre. The foliar treatment and the urea ammonium nitrate liquid treatment both had significantly less net dollars per acre than the other six treatments. (Reprinted with permission)