The Study On Suitable Concentration And The Change Rules Of Nitrogen And Phosphorus And Potassium Of Nutrient Solution In Flue-cured Tobacco Floating Seedling

Floating seedling is the main method for tobacco seedling in China. Nutrient solution concentration and the growth or decline of the nitrogen, phosphorus and potassium both has evident effect on tobacco seedling. We determine the most suitable nutrient solution concentration in floating seedling of tobacco according to the growth and physiological indexes of tobacco which grown in different concentration pools in different ages. Through the detection of the content of nitrogen and phosphorus and potassium in most suitable concentration pool and the absorbing difference of the nutrient among different tobacco varieties, we got the change rules of the content of nitrogen and phosphorus and potassium in the most suitable nutrition solution. This study provides theoretical and practical reference for the control of nutrient solution concentration and the timely addition of main nutritional components of flue cured tobacco. The results are as follows:1. The tobacco seed germinated well while the concentration of nitrogen was under 200 mg/Kg but the germination would be inhibited while the concentration was above 200 mg/Kg.2. The nutrient solution can basically meet the requirements of tobacco seedling while the concentration of nitrogen was between 100 to 200 mg/Kg. Out the consideration of the cost and the requirement of strong seedling, the nutrient solution suits floating seedling most in Shandong flue-cured tobacco area while the concentration of nitrogen was 150 mg/Kg.3. The concentration of Ammonia nitrogen and nitrate nitrogen and available phosphorus and available potassium increases from the first day to 20 th day for the water in the nutrient solution got less because of evaporation as time goes by, while the nutrient requirement is less when the tobacco seedling is at small cross time, the total nutrient component got less while the water get much less which results the increasing of the concentration of nutrient. The total nutrient component decreased constantly from 20 th day. Among them, the amount of nitrate nitrogen reduced 13.350mg/Kg, the amount of ammonia nitrogen reduced 36.373 mg/Kg, the reduction of available phosphorus was 22.930 mg/Kg, the amount of available potassium reduced 24.230 mg/Kg and the reduction of all the nutrient component increased as time goes by.4. The change rules of the concentration of nitrogen and phosphorus and potassium and basically similar among different tobacco varieties in suitable nutrient solution which showed that the absorbing rules of the main nutrient component did not vary from different varieties in flue—cured tobacco floating seedling.