Effects of forms of nitrogen supplied on the distribution of nutrients in the tobacco plant

It has been reported that the form of nitrogen supplied has a great influence on the absorption of other nutrients by the tobacco plant (1). Absorption of cations such as potassium, calcium and magnesium is decreased and that of anions such as phosphate, chloride and sulfate is increased by the supply of ammonium-nitrogen compared with that of nitrate-nitrogen. Although the responsible mechanism is probably related to antagonisms in absorption among the ions, physiological injury caused by the absorption of ammonium-nitrogen may also develop on the tobacco plant. Translocation of nutrients absorbed by the plant may be also influenced by such physiological injury. In the present paper, effects of nitrate- and ammonium- nitrogen supplied on the translocation of nutrients in tobacco plants were investigated.