Effects of Nitrogen,Phosphorus and Potassium Fertilization on Yield and Essential Oil Content of Schizonepetate nuifolia

The effect of nitrogen,phosphorus and potassium and their proportion on field and essential oil content of Schizonepetate nuifolia was studied,field experiment was based on the D-saturation optimal design with three factors of nitrogen,phosphorus and potassium.The results showed that rational fertilization can promoted yield and essential oil content of Schizonepetate nuifolia.Fertilization increased number of branches and spikes by promoted differentiation of secondary braches.Secondary braches was most in the treatment with full dose nitrogen,potassium and part phosphorus,application only nitrogen was less.Fertilization improve field of spikes to increase the entire field.The effect of compound fertilization was better than application separately,also nutrient balanced treatment was better unbalanced.With only nitrogen or nitrogen-potassium compound fertilizer raised essential oil content of stem and leaf,however high phosphorus decreased.Based on optimal mathematical models,the optimum fertilization dosage should be defined as N:195.8 kg/hm2,P2O5:92.6 kg/hm2,K2O:130.3 kg/hm2.