Effect Of Water And Nitrogen Coupling On The Yield And Quality Of Flue-cured Tobacco

Field experiments on the coupling effect of water and nitrogen on the tobacco cultivar Zhong 100 with micro-spray irrigation have been conducted in the year of 2007~2008.The influence of coupling effect between water and nitrogen coupling on the growth and the dynamic changes of water and nitrogen in the field yield, quality of the tobacco were studied in this experiment. The object was to provide theoretical evidence for the tobacco production. The main results were as follows:(1) The height, stalk perimeter and leaf area all augmented with irrigation and nitrogen increasing; Drought stress affected significantly the growth of the flue-cured tobacco. The irrigation of 300.0～600m~3/hm~2 with the nitrogen application of 52.5～70.25 kg/hm~2 was better to the growth of the tobacco.(2)The material accumulate curve present the S type in flue-cured tobacco growth stage. The dry matter accumulation of flue-cured tobacco coupling effect under irrigation rate of 300m~3/hm~2 and the nitrogen application at the range of 0-52.5 kg / hm~2 was greater than the impact of water 600 m~3 / hm~2 with nitrogen levels of 0-52.5 kg / hm~2 coupling effect. Under the irrigation rate of 300m~3/hm~2 and 600m~3/hm~2, the dry matter accumulation of flue-cured tobacco was increased with the increased nitrogen application rate.(3) The high water treatment was not conducive to the accumulation of total nitrogen content, and low water treatment was not conducive to dealing with the accumulation of nicotine content in leaves in the later period of flue-cured tobacco growth. At the water level of 300m~3/hm~2 with N 52.5 kg / hm~2 was conducive to improve the total nitrogen and nicotine in leaves. The content of total nitrogen was increased with more nitrogen application at the irrigation level of 600m~3/hm~2.(4) With the irrigation, the content of soil moisture was higher than non-irrigation treatment of 0 - 20cm soil layer in the rosette growth stage. The increased use of nitrogen fertilizers were in favor of the surface soil moisture conservation. The soil water of 0~40cm soil layer were much lesser than the moistue in the period of rosette growth stage. With the same nitrogen application, the soil water of 0 - 60cm soil layer was increased with the increased irrigation. Increased use of nitrogenous fertilizers has maintained the 0 - 40cm of soil moisture content, and promoting the 40 - 60cm of soil moisture content or take full advantage of the shift at the same time. Available nitrogen in soil was gradual lower with the soil depth. The available nitrogen of 0 - 40 cm soil layer were decreased with the increased water supply, and increased with increased nitrogen application.(5)The yield,production value and the proportion of high quality tobacco leaf all increased with the increasing of irrigation; In the nitrogen 0~52.5 kg·hm-2(treatment N1～N3),the production value and the proportion of high quality tobacco leaf increased with the increasing of nitrogen apply, but decreased when the amount of nitrogen 67.5 kg·hm-2 were applied.(6)The content of N of tobacco leaf was increased significantly by irrigation in tobacco plant. With the increasing of nitrogen apply, the content of N also increased, but the effects were less than the irrigation. Under the irrigation 300.0～600.0 m~3/hm~2 and nitrogen 52.5～70.25kg/hm~2,the quality of the tobacco leaf is better.(7) The content of petroleum ether extract was reaching the highest level in middle water (W2) treatment. The water treatments coupling with the nitrogen application at the rate of 52.5 kg / hm~2 was in favor of improving the content of petroleum ether extract of cured tobacco.(8) The content of N in cured tobacco leaf was increased with the water reduction; the content of P was increased as the water volume increased; the content of K was high water (W3)> middle water (W2)> non-irrigation (W1). Cu, Fe, Zn, Mn content generally increased as the water lowered; the content of Mg, Ca was increased with increased water supply; the content of N, P and K showed an increase with the amount of nitrogen application increased. The content of Cu, Fe, Mg and Ca was increased with the nitrogen application rate increased in the whole. The content of Zn and Mn was higher when the nitrogen application rate was lower.(9) The result showed that different irrigation, nitrogen application and their interactions on aroma component had reached a significant level except the effect of different irrigation to browning reaction substance. The content of products degraded by carotene and Neoplytadiene had reached the highest level at the irrigation of 450m~3/hm~2 .The content of browning reaction substance and products degraded by cembrane had increase firstly and then dropped at the irrigation range of 0～600m~3/hm~2. The content of products degraded by carotene, products degraded by phenylalanie, browning reaction substance and neoplytadiene had increased with the nitrogen application at mid irrigation (W2) treatment, the content of products degraded by cembrane had reached the highest level at the nitrogen application of 52.5 kg/ hm~2.