A Comparison of Ammonium and Nitrate Nitrogen for Cigar Wrapper Tobacco
1972
Rhoads, F. M.
Five N fertilizer treatments ranging from all ammonium to all nitrate were applied in a randomized block experimental design, replicated four times, to cigar wrapper tobacco (Nicotiana tabacum L.). The NH₄-N to NO₃-N ratios were as follows 1:0, 3:1, 1:1, 1:3, and 0:1. A nitrification inhibitor was applied to control nitrification of NH₄-N, and black polyethylene mulch was placed on the soil surface to minimize leaching of NO₃-N. The purpose of this experiment was to evaluate plant response of cigar wrapper tobacco to varying ratios of NH₄-N to NO₃-N. Soil samples were taken at monthly intervals and tested for NO₃-N in order to check the effectiveness of the nitrification inhibitor. Yield, quality, and nutrient content of leaves were measured as indexes of plant response. Nitrification appeared to be controlled satisfactorily by the inhibitor 2-chloro-6-(trichloromethyl) pyridine. Cigar wrapper tobacco produced a higher yield and better quality with NO₃N than with NH₄-N. Leaf concentrations of N, P, and Mg were affected very little by source of N; however, concentrations of leaf K and Ca increased as applied NO₃-N increased.
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