The Effects Of Reduced Application Of Nitrogen,phosphorus And Potassium On Polygonatum Cyrtonema Hua And Fertilization Optimization

Polygonatum cyrtonema Hua is a perennial herb of Liliaceae family,its dry rhizomes are Chinese traditional bulk medicines.It is one of the sources of Polygonatum stipulated in《Ch P 2015》.Its main medicinal compunds,such as Polysaccharide,saponin,etc,have many functions such as benefit heart,lung and kidney,strengthening muscles and bones,moistening heart and lung.In recent years,with the development and utilization of Polygonatum cyrtonema Hua,the demand of its resources is increasing day by day.It is imperative to implement the standardized cultivation of Polygonatum cyrtonema Hua,but its introduction and domestication,high-yield cultivation technology is not mature enough.Therefore,to optimize the fertilization technology of Polygonatum cyrtonema Hua,the field experiment was conducted to study the effects of N,P and K on the growth,dry matter accumulation,photosynthetic characteristics and nutrient uptake of Polygonatum cyrtonema Hua by setting up fertilizer reduction and formula fertilization（3414）.In order to improve the yield and quality of Polygonatum cyrtonema Hua and provide scientific basis for the rational fertilization of Polygonatum cyrtonema Hua under the forest in this area,a high-quality and efficient fertilization model was established based on the effects of collection,utilization and distribution,rhizome quality and main medicinal compunds.There are the main experimental result.（1）Effect of nitrogen reduction on Polygonatum cyrtonema HuaThere was no significant difference in plant height,ground diameter,root shoot ratio and other growth indexes of Polygonatum cyrtonema Hua under the reduced application of nitrogen fertilizer.The reduced application of nitrogen fertilizer（1 and 2 levels）was not conducive to the improvement of leaf transpiration and leaf net photosynthetic rate of Polygonatum cyrtonema Hua.The proper application of nitrogen fertilizer on the basis of conventional fertilization was conducive to the expansion of Polygonatum cyrtonema Hua leaf area and the increase of leaf number,which could promote the accumulation of dry matter quality of Polygonatum cyrtonema Hua plants The results showed that the content of total saponins was significantly increased,but the effect of increasing production was not significant;conventional nitrogen application（3levels）had the best effect on the accumulation of polysaccharide content in rhizome of Polygonatum multiflorum,and the leaf photosynthetic rate was the highest,the ability to use strong light was the strongest,the ability to transform light energy and the ability to use CO₂ was strong.（2）Effect of phosphorus reduction on Polygonatum cyrtonema HuaThe effect of P application level on the plant height of Polygonatum cyrtonema Hua was not obvious,and the change rule of leaf number with the application level of P fertilizer was not obvious.Proper low P treatment（1 level）could help to increase the diameter of Polygonatum cyrtonema Hua,promote the dry matter accumulation on the ground,and improve the ability of Polygonatum multiflorum leaves to use low concentration CO₂.The plant height of Polygonatum cyrtonema Hua was the highest and the leaf height was the highest when applying P fertilizer（2 levels）,There was no significant difference in rhizome yield and dry matter quality between the above ground part and the conventional P application,and the content of total saponin was the highest.Excessive P application（4 levels）could increase the ratio of rhizome to crown of Polygonatum cyrtonema Hua,but it would lead to the decrease of rhizome yield of Polygonatum cyrtonema Hua;on the basis of conventional fertilizer application,appropriate P application and reduction had no significant effect on rhizome polysaccharide content of Polygonatum cyrtonema Hua The effect of 3 levels of P application was better than that of P reduction（3）Effect of potassium reduction on Polygonatum cyrtonema HuaAppropriate reduction of potassium fertilizer（1 level）can promote the stem elongation of Polygonatum cyrtonema Hua and the proportion of rhizome dry matter in the whole plant,while the increase of potassium fertilizer（4 level）is conducive to the stem thickening of Polygonatum cyrtonema Hua,which has little effect on the leaf number and leaf area;the maximum rhizome yield and rhizome dry weight of Polygonatum cyrtonema Hua are obtained at the conventional fertilization（3 level）,while the effect of appropriate phosphorus reduction（2 level）has no significant difference At this time,the content of effective components in rhizome is the highest,and the photosynthetic capacity of leaves is strong.Under the condition of low concentration of CO₂,the effective photosynthesis can still be maintained.（4）Optimized fertilization of Polygonatum cyrtonema HuaN,P and K had significant effect on the yield and total polysaccharide content of Polygonatum cyrtonema Hua.The degree of influence of N,P and K on the yield of Polygonatum cyrtonema Hua was P>K>N,and the order of influence on the total polysaccharide content of Polygonatum cyrtonema Hua was N>P>K.A reasonable ratio of N,P and K could improve the yield and quality of Polygonatum cyrtonema Hua.Under the condition of this experiment,the confidence interval was 95%,the target yield of Polygonatum cyrtonema Hua was 10000-19300kg﹒hm^-2,and the total polysaccharide content of rhizome was 10%-13%,the fertilization scheme was n 161.3173-132.0160kg﹒hm^-2,P₂O₅ 153.0883-113.5784 kg﹒hm^-2,K₂O 76.5441-56.7892 kg﹒hm^-2,N:P:K 1:0.91:0.45.