The Optimization Study Of NPK Fertilization To Improve The Usability Of Upper Leaves Of Flue-cured Tobacco

Panzhihua is one of the most important areas developing quality flue-cured tobacco over the country with a very bright developing prospect. According to extensive management of fertilizer and low usability of upper leaves, the orthogonal rotation combination design of NPK fertilizer was applied in the fiele experiment in2010and the calibration test was taken in2011with the tobacco samples analyzed in the laboratory. The study was aimed at finding out the influence of NPK fertilizer on botanical, economic usability of upper leaves and the optimization of NPK fertilizer to improve the usability of upper leaves. Then accurate scientific proof would be offerd for the locals.The results of the research was as follows:1. The botanical influence of the usage of NPK.Adding the amount of NPK fertilizer was good for heightening the tobacco plant, augmenting the stem girth and also increasing of the LAI. Phosphate fertilizer made no significant influence on the stem girth during rosette stage and the LAI during square stage and topping stage. Adding potash fertilizer made no significant influence on plant height in birth late stage.2. The economic influence of the usage of NPK.Addition of N fertilizer and P fertilizer in a certain extent was good for increasing production, output value and the proportion of high middletobacco. While they would be decreased over the suitable range. Adding K fertilizer helps improving the production, and the proportion of the high middle tobacco, but made no influence on output value. To get a stable economic benefit,the suitable amount was N6.69～7.84kg,P2O58.81～9.17kg,K2O23.24～27.97kg/667m2.3. The influence on the upper leaf of the usage of NPK.The addition of N fertilizer and P fertilizer in a certain extent was good for the color, maturity, leaf blade structure, identity, oil content, chromaticity grades, and the appearance quality comprehensive index of flue-cured tobacco. Adding K fertilizer benefits the color, maturity, leaf blade structure grades and the appearance quality comprehensive index of the upper leaves but made little difference on identity, oil content and chromaticity grades. To improve the appearance of flue-curedtobacco, the suitable amount was N6.12～7.88kg, P2O58.93～9.38kg, K2O23.72～26.45kg/667m2.Adding N fertilizer in a certain extent was good for leaf blade thickness and stem content. But the addition of P fertilizer and K fertilizer obviously had little influence on them.To improve the physical property of the upper leaves, the suitable amount was N5.97-8.60kg, P2O51.40～9.80kg, K2O4.90-34.30kg/667m2.Adding N fertilizer properly was good fou the usability of the chemical composition contained in the upper leaves. Except for what N fertilizer does, addition of P fertilizer and K fertilizer could also harmonize the chemical composition of the upper leaves. Two formulas were better for improving the usability of the chemical composition. One was N7.27～7.68kg, P2O56.27～7.72kg, K2O25.83～27.75kg/667m2. The other one was N7.00kg, P2O56.27-8.76kg, K2O25.83～27.75kg/667m2.4. Optimization scheme of the usage of NPKOn the premise of getting a stable economic benefit, the appearance, physical property, chemical composition of the upper leaves were considered comprehensively.The suitable formula was N7kg, P2O59kg, K2O25kg/667m2in this reseach. After examination, we found out that every index was in a certain extent and optimization scheme was practicable in practice production.