Effects Of Fertilization On Physiology And Growth Of Podocarpus Macrophyllus Seedlings

In this paper,the seedlings of two-year-old Podocarpus macrophyllus(Thunb.)D.Don were used as experimental materials and fertilized by the proportion of L9(34)which contains three factors,nitrogen,phosphorus and potassium with three level,low,medium and high,to explore the effects of different fertilization treatments on the growth,physiology,leaf nutrients and photosynthetic characteristics of the seedlings of P.macrophyllus,and finally to select the best proportion of fertilizer.In addition,the quality of two-year-old P.macrophyllus seedlings were evaluated in order to provide a reasonable fertilization basis for the cultivation of P.macrophyllus,as well as provide a reference value for the protection,breeding and improvement of P.macrophyllus in the future work.The main research results of this paper are as follows:1.There were differences in growth indexes of P.macrophyllus seedlings under different fertilization treatments.After fertilization treatment for one year,the growth indexes of P.macrophyllus were measured.The results were as follows:as for plant height,leaf dry biomass,root biomass,total root volume,total root surface area,and the number of root nodules group F N2P3K1 was the best;for ground diameter group H N3P2K1;The best root length group C NIP3K3 was the best;the total root volume and average root diameter,group G N3P1K3 was the best;for leaf fresh biomass,stem biomass,above ground For some biomass and total biomass,N2P2K3 was the best in group E;N3P3K2 was the best in leaf area I group;N1P2K2 was the best in group B.The growth height,biomass and other growth indicators were considered to be the best when the N:P:K was 2.28g:9.00g:0.50g.2.The physiological indexes of P.macrophyllus seedlings changed with the seasons.The physiological indexes of P.macrophyllus were measured and the results were as follows:as for chlorophyll a,chlorophyll(a+b),soluble sugar content,the activity of SOD enzyme and POD enzyme,group H N3P2K1 was the best;for chlorophyll,group C N1P3K3 was the best;group D N2P1K2 was the best in soluble protein;the control group J(CK)was the best in the contents of free proline and MDA;group G N3P1K3 was best in root activity.Considering the various physiological indicators,the fertilization treatment is best when N:P:K is 4.57g:4.50g:0.50g.3.For the nutrient content of P.macrophyllus seedlings,the best combination of N,P and K contents was the best in N group N3P2K1,contents was the highest in N:P:K:1.14g:9.0g:2.0g.4.Photosynthetic indexes of P.macrophyllus were determined,and the results were as follows:as for the net photosynthetic rate(Pn),intercellular CO2 concentration(Ci),stomatal conductance(Gs)and transpiration rate(Tr),group H N3P2K1 was the best,contents was the highest in N:P:K:4.57g:4.50g:0.05g.Based on the comprehensive index analysis of P.macrophyllus seedlings,the seedling quality of P.macrophyllus seedlings was analyzed according to the seedling quality index and membership function.The comprehensive analysis of N:P:K was 2.28g:9.00g:0.50g,and the growth of P.macrophyllus.