Effects of Irrigation and Nitrogen Source on Nutrition and Yield and Quality of Flue-cured Tobacco

The effects of irrigation and nitrogen source on concentration of nutrients in the leaves and yield and quality of flue-cured tobacco(Nicotiana Tabacum L.) were studied in field experiment.The results showed that the content of K in flue-cured tobacco leaves increased significantly,but the content of Fe and Mn in the leaves decreased obviously under irrigation condition.With the increasing proportion of nitrate and ammonium in total rates of nitrogen fertilizer,it was found that the content of K in tobacco leaves increased remarkably,the content of Fe decreased significantly,and the change of the other elements content in the leaves was not significant.The results also showed that the distribution of N,P,K,Cu,Zn in leaves on different leaf position of tobacco plant was in the order of upper leafcutterslower leaf,but the opposite result was observed in the distribution of Ca,Mg,Fe.Moreover,the characteristic of nutrients distribution in the leaves of different leaf position was not influenced by irrigation and nitrogen source.With the increasing of nitrate rates, the high quality leaf ratio and content of total nitrogen in cured leaves were increased significantly,the content of nicotine and reducing sugar in the leaves tended to be decreased,but no significant variation was found in yield.Irrigation could remarkably improve the yield and high quality leaf ratio of flue-cured tobacco in dry land.