The pot experiments in 1988 and 1990 indicated that sodiumnitrate, ammonium nitrate, ammonium sulfate and urea did not have any remarkable di-fference in their effects on the growth, yield and quality of flue-cured tobacco because ammonium nitrogen and urea could be converted into nitrate nitrogen 20 days after being added. Except for sodium nitrate treatment, in which nitrogen conoentration in leaf and growth of plant were slightly lower in the early gr-owing stage,the effects of all treatments on yield and quality didn′t differ obvi-ously. T...
