Effect Of Fertilization Technique On Growth And Physiological Characteristics Of Catalpa Bungei

This experiment was carried out in Jinan Zaoyuan Base,Shandong Province,using a split-zone test design to conduct a water-fertilizer integrated fertilization experiment on a 2-year-old eucalyptus clone（9-1,008-1）young forest;in Shishou National Poplar,Hubei The eucalyptus gene resource bank was preserved next to the gate of the improved seed base.The randomized block experiment was used to test the fertilization test on the8-year-old eucalyptus middle-aged forest.The effects of different fertilization methods on young eucalyptus forest and different fertilization formulas on growth index,nutrient change and physiological characteristics of eucalyptus middle-aged forest were studied.The best fertilization method for young eucalyptus forests and the best fertilization formula for eucalyptus middle-aged forests were discussed.Establish a fertilization technology plan to improve the productivity of eucalyptus plantation and the quality and yield of dry wood,and provide a theoretical basis for the precise fertilization technology of eucalyptus,and further promote the rapid development of eucalyptus plantation industry.The research results are as follows:（1）Integrated fertilization of water and fertilizer can significantly promote the growth of young eucalyptus forests（p<0.05）,but there is no significant difference with conventional fertilization（p>0.05）,and the growth of different clones is slightly different.From the increase of tree height,DBH and stock volume in July-December,the ratio of height of clonal 008-1 tree to control was 95.4%,the ratio of DBH to control was 109.6%,and the increase of accumulation volume was compared with the control ratio.110.2%.The clonal 9-1 tree height increase was 94.3%higher than the control ratio,the DBH increment was 104.5%,and the accumulation volume increment was 103.5%.In general,the integrated fertilization of water and fertilizer before the onset of the vigorous growth period can effectively improve the production efficiency of young eucalyptus forests.（2）The effects of water and fertilizer integration on soluble sugar,starch and non-structural carbohydrate content in young shoots and leaves of young eucalyptus were not significant（p>0.05）.In October,the soluble sugar content of leaves was positively correlated with tree growth,and the starch content of leaves was negatively correlated with growth.There was no obvious correspondence between non-structural carbohydrate content and growth.Clonal 9-1,leaf soluble sugar content,starch content,non-structural carbohydrate content and tree growth were negatively correlated.The dynamic law showed that the accumulation of soluble sugar and non-structural carbohydrates in the late growth stage was greater than that in the vigorous growth period,and the starch accumulation was less than the vigorous growth period.In general,different tree species and different clones have different accumulation and conversion mechanisms for sugar,starch and non-structural carbohydrates,and should be combined with specific growth indicators and nutrient contents for analysis.（3）Integrated fertilization of water and fertilizer had no significant effect on the ratios of total nitrogen,total phosphorus,total potassium,nitrogen and phosphorus of leaves and branches of eucalyptus 008-1（p>0.05）,but significantly increased leaves and shoots.Organic carbon content,as well as carbon to nitrogen ratio of shoots（p<0.05）.The effects of total nitrogen,total phosphorus,nitrogen-phosphorus ratio,carbon-nitrogen ratio,total nitrogen content and nitrogen-phosphorus ratio of leaves of clone 9-1 were not significant（p>0.05）,but could significantly increase leaf total potassium and organic.Carbon content,as well as total potassium,organic carbon content and carbon to nitrogen ratio of shoots（p<0.05）.On the whole,different clonal lines have different requirements for nutrient elements and different absorption and utilization efficiencies.According to the characteristics of tree species,the plant should be nutritionally diagnosed and the soil testing formula should be planned and fertilized.（4）Rational NPK fertilizer topdressing for middle-aged eucalyptus forests,N 30g/plant,P₂O₅10 g/strain,K₂O 20 g/strain（treatment A）,to some extent,promote eucalyptus middle age The forest grew,but the promotion effect was not significant（p>0.05）.For treatment A,the increase of tree height from 3 to December was 129.4%,the ratio of DBH to control was 123.1%,and the increase of accumulation was 120.6%.Taking into account the cost factor,the middle-aged eucalyptus forest does not need to be topdressed.（5）The NPK formulation of middle-aged forests could significantly increase the content of soluble sugar and non-structural carbohydrates in leaves and shoots of mid-July forest in July（p<0.05）,but the effect on starch content was not significant.（p>0.05）.The dynamic law showed that the accumulation of soluble sugar,starch and non-structural carbohydrates in shoots at the end of growth was lower than that in the vigorous growth period.Whether the improvement of physiological indicators by fertilization can be used for the growth of trees and increase productivity,which needs to be continuously observed.（6）The effect of topdressing on the total nitrogen,total phosphorus,total potassium content and nitrogen-phosphorus ratio of the middle-aged forest was not significant（p>0.05）,but it could significantly increase the leaf organic carbon content and carbon-nitrogen ratio（p<0.05）.The effects of total nitrogen,total phosphorus,total potassium,organic carbon,carbon to nitrogen ratio and nitrogen-phosphorus ratio were not significant（p>0.05）.Different tree species have different requirements for nutrient elements and different absorption and utilization efficiency.According to the characteristics of tree species,the plant should be nutritionally diagnosed and the soil testing formula should be planned and fertilized.