Abstract:Continuous cropping obstacle (CCO) causes serious losses in agricultural production. Chinese medicinal herb cultivation also faces the same difficulty. In order to find a green, non-polluting, environmentally friendly and sustainable prevention and controlling method for CCO, plot experiment in a field cultivating medicinal Chrysanthemum for ten years more were carried out. There were six treatments with two seedling methods multiplying three fertilization methods, D and T were represented local seedling method and optimized seedling method respectively. The three fertilization methods were represented respectively by CK as local treatment, T1 as applying conditioner and cut off 20% of N supply, and T2 as applying conditioner and cut off 40% of N supply. The results showed that: 1) Biomass, plant height, branch number and leaf area were significantly higher in optimized seedling treatments, compared to local seedling treatments. Biomass and branch number of treatment TCK were significantly higher than those of treatment DCK (1.26 and 2.5 times of DCK), respectively. Biomass, plant height, branch number and leaf area in treatment DCK did not show significant difference with treatment DT1, in which N supply was cut down by 20%. 2) Plant yield, flower and bud number in treatments of two seedling methods showed the same trend as above. Meanwhile, yield and flower and bud number per plant in treatment TT2 did not show significant difference with that of treatment DCK. The flower-bud ratio of optimized seedling was slightly higher than that of local seedling. 3) Optimized fertilization methods had positive effect on plot yield, plot yield in treatment TT1 was 1.88 times of that in treatment DCK and reached extremely significant level. The results indicated that under optimized fertilization model the plant height, branch number and leaf area in flowering stage were improved so that biomass accumulation increased. Flower and bud number, dry weight of the flower and flower-bud rate were improved in a certain degree, yields increases as a result, thus negative influence caused by cutting N supply were compensated. Optimized seedling is more effective than optimized fertilization.