| In order to find the optimum fertilization scheme of Horsfieldia hainanensis Merr.Seedling,the "3414" experiment was carried out to study the effects of different fertilization treatments on the growth,physiological,photosynthetic characteristics and nutrient contents of seedlings.By measuring relevant indexes,the quality of the seedlings was evaluated comprehensively.It reveals the change of growth and the rule of nutrient absorption and utilization,establishing a balanced fertilization model to provide practical guidance for the production and application of this plant.The main results are listed as follows:1.There are significant differences in the growth indexes of Horsfieldia hainanensis Merr.seedlings.The height and ground diameter growth,above-ground biomass,ground biomass,total biomass,specific leaf weight and root-related indexes of the non-fertilization group are lower than those of other fertilization groups.NPK factors have significant effects on the growth index of seedlings.The plant height increment and total root length of N2P1K2 treatment are all higher than those of the other groups,while the maximum of ground diameter increment,ground biomass and root surface area,as well as the minimum of shoot-root ratio appears in N2P2K2 treatment.Specific leaf weight reaches the maximum in group N1P1K2,and the total biomass is largest in group N2P2K1.However,group N3P2K2’s number of primary lateral roots is the highest.2.The differences of physiological indexes among the groups are significant.The soluble protein,soluble sugar and chlorophyll content in July are obviously higher than those in October.In July,the highest content of soluble sugar appears in group N3P2K2,then it became N2P1K1 in October.The groups having the highest soluble protein and chlorophyll content are unchanged,being N3P2K2 and N2P2K1 respectively.3.The nutrient contents of Horsfieldia hainanensis Merr.seedling leaves are notably affected by fertilization.The highest amount of Nappears in N2P2K2 treatment,but the content of P reaches the maximum in group N1P2K2.While,the content of K in N2P2K3 treatment is higher than others.The data show that some element’s content in the leaves is mostly affected by that element,and the loss of some element will affect the absorption and accumulation of the other two nutrient elements.4.After the different fertilization treatments,the Pn,Gs,Tr and Ci of the seedlings in fertilization group are higher than those of the non-fertilization group,showing the seedlings’ photosynthetic performance is improved.The Pn,Gs and light response curves show that the highest Pn appears in the N2P2K2 treatment,while the N2P2K1 treatment has the largest Tr and the group N2P2K3 has the highest Ci.5.By the correlation analysis,it is found that the majority of the similar indicators are often significant,positively correlated with each other,except some special indicators.Different kinds of indicators have significantly correlation with others,reflecting the interaction between the various characteristics of plant.According to the fuzzy comprehensive evaluation of membership function,the best treatment is N2P2K2 and the most undesirable treatment is NOP2K2.In the evaluation system of seedling quality index,the best treatment is N2P2K2,while the NOP2K2 treatment performs most undesirable.According to the quality index of the seedlings,the ternary quadratic fertilizer effect function is founded:Y=1.11+0.77N+1.08P+2.19K-0.07N2-5.75P2-0.94K2+1.05NP+2.76PK-0.29NK.And quadratic fertilizer effect functions are:Y=1.28+1.02N-0.10 N2,Y=1.57+7.25P-6.38P2,Y=1.84+4.24K-1.70K2. |
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