Study On The Effects Of Different Fertilization Ratio On Growth And Stoichiometry Of Cunninghamia Lanceolata (Lamb.) Hook At Seedling Stage

In order to explore the effects of different ratios of nitrogen fertilizer and phosphate fertilizer on the growth and stoichiometry of water-flooded Chinese fir seedlings,the best management scheme for cedar fertilization was screened.In April 2015,different nitrogen fertilizers and phosphate fertilizers were developed for three-year-old melted Chinese fir seedlings.The fertilization test was conducted to analyze the relationship between soil and leaf growth indicators,the structural changes of soil enzymes,the ecological stoichiometry of leaves and soils,and the effects of leaf nutrients.The results showed that:.1.Nitrogen application,phosphorus fertilizer and nitrogen and phosphorus application increased the chlorophyll content of leaves,and N1 treatment increased leaf photosynthetic pigments most obviously,and nitrogen fertilizer was more conducive to pigment synthesis and accumulation than phosphate fertilizer.The blade Chla:Chlb ratio reached 4.2:1,and the blade ratio was balanced.Nitrogen and phosphorus combined application is more conducive to the growth of plant height,and N1P1 is the most obvious.2.The contents of C,N and P in leaves and soil of mullet were significantly increased by different fertilization ratio experiments.Among them,single application of nitrogen fertilizer and single application of phosphate fertilizer,the N:P of the fused fir leaves were>15,the leaf N concentration was less than 20.0 mg/g,but the P concentration was higher than 1.0 mg/g.It is speculated that the growth of the fused fir was not restricted by P.Ni and P combined with N:P were both<14,and the leaf N concentration was less than 20.0 mg/g,indicating that the growth of fused fir was limited by N.The N concentration of N1P1 leaves was the highest,and it was speculated that N1P1 treatment could initially alleviate the nutrient limitation of melted Chinese fir seedlings.Different ratios of nitrogen and phosphorus can effectively improve the quality of seedlings of melted Chinese fir seedlings,and the diameter of the ground is the largest under N2P1 level.3.After the fertilization ratio test,the available phosphorus in the soil of the sapling seedlings increased greatly from 5.75 mg/g to 108.74 mg/g;the available nitrogen also increased slightly from 35.35 mg/g to 53.54 mg/g.Combined with the results of fertilization experiments,the activities of soil enzymes such as invertase,urease,phosphatase and catalase were increased,and the combination of nitrogen and phosphorus significantly increased the activities of soil invertase,urease and catalase.Soil phosphatase activity..