Study On Coupling-effect Of Water And Nitrogen Of Tobacco In Water-saving Condition

Yield and quality are the key factors to the economic benefit of tobacco, which is the vital important economic crop. And the two factors have inseparable relation, whose decisive factor is soil water and fertilizer. The dosage of water and fertilizer in a certain scope do have active work to the yield and quality of tobacco, while it becomes deficient or sufficient, the yield and quality will be incapable to be ensured. By mensurating the soil water content, the quick acting nitrogen content of soil, the agronomic character, the physiological and ecological index, the yield and quality of flue cured tobacco which grows in different level of water and nitrogen in lysimeter, this text carries out several aspects research such as follows:(1) The agronomic character and the index of physiological and ecological of flue cured tobacco are mensurated in the experiment. Then by analysis, we get that the dynamic alteration law of the index of leaf area (LAI) obeys to the statistic model of Logarithmic function, and there lies good correlations between cell fluid consistence with such three factors as soil moisture content of different soil layer, and the occurance of peak of cell fluid consistence daily variation delays with the increasing of nitrogen fertilizer., etc.(2) By carrying out controlled-irrigation during the whole growing period in the condition of soil moisture and nitrogen coupling, we got that nitrogen fertilizer has benefit to increase the volume of water-consuming, and meanwhile it can heighten water utilization efficiency of flue cured tobacco.(3) By mensurating and analyzing mineral nutrition element content of each several part of flue cured tobacco of maturity stage, we got that the accumulation dose of nitrogen(N), Phosphorus (P) and p0lassium (K) of root, stem and leaf will increase with nitrogen fertilizer, but surplus nitrogen fertilizer will decrease the accumulation dose of flue cured tobacco. (4) We carried out mensurating and analyzing dry matter in the maturity period, and got that nitrogen fertilizer can heighten the proportion of tobacco better than average ,increase the accumulation of dry matter and the work to ground parts lager than underground parts.