RESUMO
Inula japonica was used as the research object, "3414" fertilization experiment were conducted to study the effects of nitrogen,phosphorus and potassium formula fertilizer on the growth and chemical composition content of I. japonica. The characteristics of fertilizer requirement were preliminarily revealed and the study provided fertilization guidance for artificial cultivation of I. japonica. The results showed that different nitrogen,phosphorus and potassium formula fertilizers had significant effects on plant morphology,physiological and biochemical indexes,dry matter accumulation and chemical composition content. The growth indexes and chemical components of I. japonica showed an upward trend with the increase of fertilization amount,especially the nitrogen fertilizer was the most significant. The indicators were analyzed by membership function. After comprehensive evaluation,the optimal nitrogen,phosphorus and potassium formula fertilization level was N3 P2 K2,namely high level nitrogen fertilizer,medium level phosphorus fertilizer and potassium fertilizer. I. japonica is a high fertilizer demand plant,and the rational fertilization scheme is " applying nitrogen fertilizer again and applying phosphorus and potassium fertilizer properly".