Application Effects of Nitrogen,Phosphorus and Potassium on Yield and Quality of Spherical Fennel

The three factor quadratic D-saturation optimization design(310) was used to investigate the effects of nitrogen,phosphorus and potassium fertilizer on the yield and VC content of spherical fennel,and then their multinomial regressive models were obtained.The results showed that all of the regressive models were non-typical functions.The optimal ranges of nitrogen,phosphorus and potassium for high yield were 2.821~10.318 kg N,0.9331~1.4666 kg P2O5,and 1.6005~6.754 kg K2O per 666.7m2 and the predicted highest yield was 1 242.67 kg per 666.7m2.The optimal ranges of N,P2O5 and K2O for VC content were 1.0395~6.4015 kg N,0.9331~1.4666 kg P2O5 and 1.6005~6.754 kg K2O per 666.7m2,and the predicted highest content of VC was 8.5504 mg per 100 g.In conclusion,the optimal amounts for high yield and good quality were 2.8465~6.4015 kg N,0.9331~1.4666 kg P2O5,and 1.6005~6.754 kg K2O per 666.7m2.