Effects Of Sowing Date, Seedling Substrate And Nitrogen, Phosphorus And Potassium Fertilizer Application On The Growth And Quality Of Panax Notoginseng Seedlings

Panax notoginseng（Burk）F.h.Chen is a kind of perennial herbaceous plant of Panax ginseng in Acanthopanax family.It has high medicinal value and large market demand.It is a valuable and large amount of traditional Chinese medicine in China.High quality seedlings are the key to the cultivation of Panax notoginseng,In order to meet the needs of the development of Panax notoginseng production,especially the requirements of new production areas,and to explore the optimization conditions of Panax notoginseng seedling,this experiment set up the suitable sowing time of Panax notoginseng seedling,different matrix ratio and"3414"soil testing formula fertilization on the growth and quality of Panax notoginseng seedlings in Guiyang area,In order to provide technical support and theoretical basis for cultivating healthy and high-quality seedlings of Panax notoginseng,the main results of this paper are as follows:（1）The results of two years’continuous sowing date test showed that January and February were more suitable for the sowing of Panax notoginseng seeds in Guiyang.In January 2019 and February,the height of plant height,root diameter,leaf area,seedling index,seedling rate and SPAD value of 37 seedlings planted in the same period were significantly higher than those of 37seedlings planted in March,but the incidence rate was opposite.The seedlings of Panax notoginseng planted in January and February of 2019 and 2020 grew well,and there was no significant difference in SPAD value.The main root diameter,strong seedling index and disease rate of Panax notoginseng seedlings sown in January and February 2020 were higher than those sown in January and February 2019.The trend of plant height,aboveground fresh weight and leaf area was opposite.（2）Earthworm dung,coconut bran and peat were used as the main matrix materials to obtain the compound matrix suitable for the growth of Panax notoginseng seedlings.Coconut bran group:T5（coconut bran:peat:vermiculite:raw soil=0.5:1.5:1:1）,T6（coconut bran:peat:vermiculite:raw soil=1:1:1）,T7（coconut bran:peat:vermiculite:raw soil=1.5:0.5:1:1）,T8（coconut bran:vermiculite:raw soil=2:1:1）（V:V）had smaller bulk density,larger porosity,and the size porosity ratio was close to the optimal value of 0.5（T5 equal to 0.5）,The p H value was in the suitable range for the growth of Panax notoginseng seedlings,the content of organic matter was high,and the total nitrogen,total phosphorus,available phosphorus and alkali hydrolyzable nitrogen were similar to CK（peat:vermiculite:raw soil=2:1:1）（V:V）.The growth of Panax notoginseng seedlings was closely related to the physicochemical properties of the composite matrix,and the physicochemical indexes of the matrix had a great influence on the strong seedling index of Panax notoginseng seedlings.The contents of chlorophyll a,chlorophyll b and chlorophyll a+B in CK were the highest,and T5 and T6 were close to them.The net photosynthetic rate（Pn）,transpiration rate（E）and stomatal conductance（GS）of CK were the highest,followed by T5 and T6,and intercellular CO₂concentration（CI）of CK was the lowest,which indicated that CK,T5 and T6 had stronger photosynthesis.The comprehensive ranking of membership function values of T5,T6,T7 and T8 was higher than that of CK,and T5 ranked the highest.The root fresh weight,shoot fresh weight,root shoot ratio,seedling index and g value of T5 were better than those of other treatments,increased by 34.84%,12.5%,14.58%,84.05%and37.5%respectively.The results showed that T5 was more suitable for the growth of Panax notoginseng seedlings than CK（peat:vermiculite:raw soil=2:1:1）（V:V）.In October,the contents of chlorophyll a,chlorophyll b and chlorophyll a+B were the highest in treatment 11（n3p2k2）,and the lowest in treatment 1（n0p0k0）.（3）Through the"3414"field fertilization research,we can get the best fertilization ratio and amount of Panax notoginseng seedlings under the experimental conditions.The contribution rate of soil fertility was 53.7%,so the soil fertility of the experimental land was relatively low.The nutrient deficiency analysis of each index showed that the primary influencing factor of the three fertilizers was K fertilizer,followed by N fertilizer and P fertilizer.The results of dynamic sampling showed that fertilization could significantly promote the growth and quality of Panax notoginseng seedlings,and the N,P and K fertilizer requirements of each growth and quality index of Panax notoginseng seedlings were different at different growth stages.The results showed that reasonable fertilization ratio had a great effect on the growth of root fresh weight,seedling index and root shoot ratio of Panax notoginseng seedlings;The results of physiological index analysis showed that cat activity of treatment 11（n3p2k2）,treatment 6（n2p2k2）and treatment 10（n2p2k3）was relatively high,CAT activity of treatment 1（n0p0k0）and treatment 2（n0p2k2）was relatively low,on the contrary,MDA content was relatively high.The SPAD value of treatment 11（n3p2k2）was the best.The SPAD value of no fertilization treatment was significantly lower than other treatments.The results showed that treatment 11（n3p2k2）,treatment 3（n1p2k2）and treatment 6（n2p2k2）had stronger photosynthesis,which was beneficial to the growth and quality of Panax notoginseng seedlings;According to the comprehensive analysis of membership function method,when the fertilization ratio was treatment 3（N₁P₂K₂）,the growth and quality of Panax notoginseng seedlings were the best,followed by treatment 2（N₀P₂K₂）and treatment 12（N₁P₁K₂）.Combined with the subordinate function method and the single factor fertilization effect equation of N,P and K,the optimal N,P and K fertilization ratio of Panax notoginseng seedlings in this experiment is N₁P₂K₂,and the optimal recommended fertilization amount is N fertilizer 6 kg/kg/667m²,P fertilizer 8.64 kg/kg/667m²and K fertilizer 14.22 kg/667m².