Fertilization model of nitrogen, phosphorus and potassium based on quality index of tobacco leaves

Thiastudy was conducted to provide a quantitative fertilization model for high quality tobacco leaves production and low environmental pollution resulted from overfertilization. A pot and a field experiment with the regression unitized design were carried out to study the effects of N, P and K fertilizers on internal quality indexes in fluecured tobacco leaves. Tobacco leaf inherent quality in the experiment was scored by the fuzzy comprehensive evaluation, and weights of tobacco quality indexes were identified by the analytic hierarchy process (AHP). Regression equations of the relation of the tobacco quality index to nitrogen, phosphorus and potassium fertilizer were established basing on the fuzzy comprehensive evaluation and then were optimized. The results showed that the optimal application amounts of N, P and K fertilizers in the pot experiment were N 4.51-6.14 g/pot，P2O5 6.48-10.48 g/pot, K2O 20.31-28.60 g/pot. The fertilization model of the nitrogen, phosphorus and potassium fertilizers containing the soil fertility contribution rate, tobacco cultivars and other parameters were developed based on the optimization of the regression equation and verified by the field experiment. The results showed that the recommended amounts based on the fertilization model were N 54.22 kg/ha，P2O5 95.85 kg/ha，K2O 347.26 kg/ha，which were in concert with the recommended amounts from the field experiment.