Abstract: In order to explore the theoretical basis of rational fertilization technology of Hongda flue-cured tobacco, the field experiment was carried out to study the effects of different nitrogen fertilizer application rates on dry matter accumulation in different organs and nutrient absorption of Hongda flue-cured tobacco. The results showed that the dry matter and nutrient accumulation increased with the increase of nitrogen application rate. Meanwhile, the treatment of pure nitrogen 45 kg/hm² was the lowest and the treatments of pure nitrogen 75 kg/hm²、90 kg/hm² were better. The dry weight of Hongda flue-cured tobacco leaves increased sharply from tuanke-period to vigorous growing period under different nitrogen fertilizer levels, and the accumulation of nutrient elements in flue-cured tobacco leaves increased 12~58 times from tuanke-period to vigorous growing period. The content of nitrogen, phosphorus, potassium, zinc and boron in flue-cured tobacco leaves reached the absorption peak in vigorous growing period, the content of magnesium in flue-cured tobacco leaves reached the absorption peak in tuanke-period, and the content of phosphorus and boron in flue-cured tobacco leaves was low. It is recommended to apply pure nitrogen 75~90 kg/hm² and increase phosphate and boron fertilizer in Hongda flue-cured tobacco. It is suggested that nitrogen, phosphate and potassium fertilizer should be used as base fertilizer and additional fertilizer before tuanke-period, which can promote dry matter and nutrient accumulation in vigorous growing period of flue-cured tobacco, and boron fertilizer should be sprayed on leaves in vigorous growing period to improve flue-cured tobacco quality.

Key words: Hongda flue-cured tobacco, nitrogen fertilizer, dry matter accumulation, nutrient uptake