Effects Of Density And Fertilizer On Yield And Quality And Mineral Element Absorption Of Bupleurum Falcatum L.

Bupleurum falcatum L.is an important herbal medicine in common use.Because of more requirments needed in clinic, Bupleurum falcatum L.is planted more and more widely in many areas.But the studies of planting techniques are poor,its planting techniques have not been studied Bupleurum falcatum L. is selected in this experiment.In order to find the best cultivation mode,we studide the effect of density and potassium fertilizer on yield and quality.And the physiological mechanism how density,potassium fertilizer affected yield and quality were analyzed in this experiment.The main results were as followed:1 Effect of fertilizer on yield and quality of Bupleurum falcatum L.The application of N, P and K fertilizer with rational ratio were beneficial to the growth of Bupleurum falcatum L. in each growth stages. However,the requirement amount and urgent degree for N, P and K were significantly different in every growth stages. In elongation stage in the first year, The rational application of N, P and K fertilizer could increase the growth of shoot and root. Particularly,the over application of N and K fertilizer had harmful effect, but the over application of P have the opposite effect. From flowering to fruiting in the first year, the requirement amounts for N, P and K were high,however,over and mere application of K fertilizer was beneficial. In seeding and elongation stage in the second year, the requirement amount for N and P was higher and that of for K was relatively less, but the over application of P had harmful. After flowering and fruiting, the over application of P and K would result in decreasing the root dry weight. The result showed that application of 186.6 kg/hm²N ,0 kg/hm² P and 243.0 kg/hm² K fertilizer could reach to the maximum of Bupleurum falcatum L.With the growth of plants, saikosaponin content of one-year-old and two-year-old B. falcatum L.increased firstly, then decreased. The peak appear in the elongation stage. However, the total saikosaponin yeild of shoot and root have different trends in different fertilization treatments. The rational application of N fertilizer could increase the saikosaponin a c d content. But the over application of K fertilizer had harmful effect on saikosaponin a and c in fruiting stage in the first year, but the saikosaponin d had little effect. The over application of P would result in restraining the accumulation of saikosaponin a and d of one-year-old B. falcatum L.However, the over application of N and P fertilizer would accelerate to the accumulation of saikosaponin a c d content of the root of two-year-old B. falcatum L. Particularly, the over application of K fertilizer had harmful effect. The K fertilizer could increase saikosaponin contents of the shoot , and the N fertilizer only improve the accumulation of saikosaponin a and d contents,but the P fertilizer have little effect.The most suitable amount for saikosaponin content in fruiting stage of the root of one-year-old B. falcatum L.were N 93.3kg/hm²,P₂O₅ 0 kg/hm² ,K₂O 121.5 kg/hm². The most suitable amount for saikosaponin content in harvesting stage of the root of two-year-old B. falcatum L.were N 186.6kg/hm², P₂O₅ 546.2 kg/hm² ,K₂O 0 kg/hm².2 Effect of N P K fertilizer on mineral element absorption and distribution in Bupleurum falcatum L.The rule of absorption,accumulation and distribution of N,P and K was studied.According to the experiment result,the application of P and K fertilizer had negative influence on the absorption of N,P and K in B. falcatum L.,but the application of N fertilizer could promote the absorption of N in seeding and late growth stage of the root of one-year-old B. falcatum L.and in later growth stage of the root of two-year-old B. falcatum L.. Appropriate application of N fertilizer had positive effect on P absorption in early growth stage of the root of one-year-old B. falcatum L.and in later growth stage of the root of two-year-old B. falcatum L.. The over application of K fertilizer would result in decreasing the absorption of P in fruiting of one-year-old plants and in seeding of two-year-old plants,and having negative effect on K absorption in the later growth stage of the root of one-year-old B. falcatum L.. The application of N fertilizer ameliorate K nutrition in two-year-old B. falcatum L.'s roots.Appropriate application of N fertilizer had positive effect on N absorption in shoot,and the N absorption could be promoted if the K fertilizer used properly in the later of elongation stage.The N fertilizer had effect on P absorption in shoot,but the over used in early growth stage is harmful.The over application of P fertilizer could promote the K nutrition in the shoot of one-year-old B. falcatum L.,but the application of N fertilizer had positive effect in shoot of two-year-old B. falcatum L..The N,P and K nurtition accumulate primarily in the shoot of one-year-old plants, and the root had little nurtition.But the root had a large proportion in seeding stage of two-year-old plants.The stem became the main organ of nurtition elements in elongation stage, after flowering ,the proportion of nurtition improved in flower in the later elongation stage and the allocation in stem and leaf decend obviously. Varying with the growth stages,the accumulation center of N,P and K changed gradually. The absorption of N and P nurtition had increased quickly in flower and fruit at boomed flowering stage,but the K absorption is droping quickly. From fruiting to dormancy,the N,P and K content in the root is increasing as result of the plant had fade partly.3 Effect of density on yield, quality and mineral element absorption and distribution in Bupleurum falcatum L.With increasing of plant density, the root yield of single plant decreased, but root yield of colony increased at the later growth stage.With the growth of plants, total saikosaponin content of one-year-old and two-year-old B. falcatum L.increased firstly, then decreased. The peak appear in the elongation stage.At the later growth stage, low density 384615 plant/ hm² and 500000 plant / hm² were higher than other treatments in one-year-old Bupleurum falcatum L.,and 384615 plant / hm² reached to the first at fruiting stage.Totol saikosaponin content decreased when the density increased in two-year-old Bupleurum falcatum L..The saikosaponin a,c,d content of root reached to the peak at elongation stage, and decreased when the densty increased at fruiting stage.Low density were higher than high density in later growth stage,but the two low densities had no significant difference in two-year-old Bupleurum falcatum L..The saikosaponin content of the shoot in early stage is higher than the later, and no significant difference among treatments at the flowing stage.At the fruiting stage, 384615 plant/ hm²reached to the maximum.The appropriate colony density is conducive to the maintenance of the lower N nutrition at the early growth and the higher N and P nutrition at the later growth in Bupleurum falcatum L..The rait of N: P and P: K of 500000 plant / hm² is highest .With increasing of plant density, the absorption of N,P and K decreased in one-year-old of B. falcatum L., and the density of 500000 plant / hm² distributing to the root for nutrition is the highest during treatments in the first year. The phosphorus sorption and assignment in two-year-old of B. falcatum L.is same as the first year, but the density of 500000 plant / hm² has the maximum absorption of nitrogen and potassium .