Effects of nitrogen application rate on the growth of flue-cured tobacco in three sorts of tobacco-planting soil

The pot experiment was conducted to study the effects of nitrogen application rate in three tobacco-planting soils on the growth of flue-cured tobacco. Nitrogen application rate in tobacco-planting soil with different available nitrogen contents exerted significant influence on the growth of tobacco plants. Tobacco plants of N4treatment( nitrogen application 1. 90 g per pot) in moist sandy land( available nitrogen 105.45 mg·kg- 1) grew best,tobacco plants of N3treatment( nitrogen application 1.45 g per pot)in yellow podzolic paddy field( available nitrogen 127. 27 mg·kg- 1) grew best,and growth of tobacco plants of N4treatment in paddy field( available nitrogen 184.31 mg·kg- 1) was inhibited in prophase and interim of transplanting. Different nitrogen rates had different effects on growth period of tobacco plants in those three kinds of soil,it was not conducive to the growth process of tobacco plants when the amount of nitrogen application was too high or too low. There was significant or extremely significant positive correlation between the biological yield of flue-cured tobacco and the amount of nitrogen application,but it was not conducive to the normal maturity of tobacco leaves if nitrogen application rate was too high. Under the conditions of this pot experiment,it was more beneficial to the growth of flue-cured tobacco when the amount of nitrogen application was 1.90 g per pot in moist sandy land,1.35g per pot in yellow podzolic paddy field,0.90 g per pot in paddy field,respectively.