Abstract:

To reduce the nitrogen application rate on tobacco in the paddy-tobacco growing area and clarify the effect of nitrogen reduction fertilization mode on paddy-tobacco, taking flue-cured tobacco variety ‘Yunyan 87’ as the test material, a field experiment was conducted to study the effects of nitrogen reduction fertilization mode and traditional fertilization mode on growth, dry matter accumulation, yield and quality of paddy-tobacco. The results showed that the nitrogen reduction fertilization mode was beneficial to the early growth of tobacco in the field and the development of middle and lower tobacco leaves, the mode increased the total dry matter accumulation of tobacco by 5.03%, promoted the dry matter distribution to tobacco leaves. Under the nitrogen reduction fertilization mode, the contents of total sugar, reducing sugar and potassium in middle leaves increased by 5.99%, 5.42% and 0.14% respectively; the nicotine content of middle and upper leaves decreased by 0.37% and 0.09% respectively, that of lower leaves increased by 0.4%, and the availability of chemical components in flue-cured tobacco was improved. The nitrogen reduction fertilization mode can be adopted by reducing the basal nitrogen and increasing the proportion of topdressing nitrogen, applying basal fertilizer in holes, increasing the watering root fertilizer and multiple watering the topdressing fertilizers, to reduce the amount of nitrogen fertilizer, improve the quality of tobacco leaves and increase the income of tobacco farmers in paddy-tobacco growing area of south China.

Key words: flue-cured tobacco, fertilization modes, tobacco growth, dry matter accumulation, tobacco leaf quality