| Machilus pauhoi Kanehira is an evergreen tree in Lawraceae Machilus Nees,a rare native tree species in Guangxi,which is one of the precious native species in Guangxi.It has been planted on a large scale and has established a demonstration area for shaving plant in Guangxi's western region.The fertilization of trees can improve the nutritional status of trees and the soil fertility of woodland,promote the growth of trees and improve the productivity of forest land.However,the research on the fertilization experiment of Machilus pauhoi Kanehira was not reported.Therefore,this study was based on the 2-year-old Machilus pauhoi Kanehira young forest in Dagui Mountain Forest Farm,Hezhou City,Guangxi,using N,P,K three-factor three-level orthogonal design to studied the effects of N,P and K fertilizers on the growth physiology and soil properties of the young plant of Machilus pauhoi Kanehira.The optimum fertilization formula was explored in order to develop this excellent tree species and improve the fertilization effect and promote the fertilization Forestry industry sustainable development to provide a certain scientific theoretical basis.The main findings are as follows:(1)Compared with the non-fertilized CK group,the fertilization treatments promoted the growth of Machilus pauhoi Kanehira,the groung diameter,DBH,crown width,leaf area and biomass.The best effect was the treatment group T5(N2P2K3,Urea 129.31g,superphosphate 333.33g,potash 75g),the best effect on the ground diameter and DBH was T6(N2P3K1,urea 129.31g,superphosphate 500g,potash 25g),the leaf area between the treatment groups between 36.18-51.17 cm2.The effects of nitrogen,phosphorus and potassium on the growth of tree height,leaf area and biomass accumulation were all N>P>K,and the effect on the diameter,diameter of DBH and crown was P>N>K,fertilizer had no significant effect on leaf area.In a word,medium and high level of phosphate fertilizer and low level of potash fertilizer was better than that of other three levels.(2)Compared with CK group,the chlorophyll content,soluble sugar content,soluble protein content,nitrate reductase activity,net photosynthetic rate,stomatal conductance and transpiration rate were increased,while the intercellular carbon dioxide decreased.The effect of nitrogen fertilizer on chlorophyll content,nitrate reductase activity,net photosynthetic rate,intercellular carbon dioxide and transpiration rate were higher than that of phosphate fertilizer,and the effect of phosphate fertilizer on soluble sugar content and soluble protein content was the highest,and the effect of potash on the stomatal conductance is greater than the phosphate fertilizer.At different levels,the indicators will rise with the rise of nitrogen level after the first rise and fall,with the increase in the level of phosphate fertilizer is rising,for the potassium,the low potassium level to perform better.(3)After adding N,P and K fertilizers,the pH value of forest land decreased slightly,the content of organic matter in soil,total nitrogen,phosphorus and potassium content,available N,P and K contents,microbial biomass content and enzyme activity increase.Nitrogen and phosphate fertilizers had a significant effect on soil enzyme activity.Potassium fertilizers had a significant effect on phosphatase,and their effects on urease and sucrase were also significant,but they had no significant effect on catalase.(4)The contents of N,P,K and N:P were significantly higher in the fertilization group after fertilization with nitrogen,phosphorus and potassium,and the element content and N:P ratio were different.The highest nitrogen and phosphorus in the leaves were the treatment group T6(N2P3K1),and the nitrogen content of the treatment group with lower nitrogen level was lower.The highest potassium content in the leaves was treated with T5(N2P2K3).In addition to treatment group T3(N1P3K3,urea 64.65g,superphosphate 500g,potash 75g),T7(N3P1K3,urea 193.96g,superphosphate 166.67g,potash 75g)and CK group,the other groups of N:P ratio between 14 to 16,indicating that no restrictions on nitrogen and phosphorus nutrients.(5)Correlation analysis showed that there was a strong positive correlation between plant growth index and physiological index,except for the negative correlation between the intercellular carbon dioxide concentration and other indexes.The pH value of soil was not positively correlated with the activity of catalase,but not with the other indexes.There was a significant positive correlation between the other soil nutrient indicators,leaf nutrient,soil and leaf nutrients,and between growth physiological index and nutrient index.(6)The growth physiology indexes of Machilus pauhoi Kanehira and the nutrient indexes of soil and leaf were evaluated by fuzzy comprehensive evaluation.The average of the subgroups of T6 was the highest,that is N2P3K1.Fertilization has the best effect on the growth and physiological metabolism of Machilus pauhoi Kanehira,and can improve the soil nutrient status and improve soil fertility. |
PDF Full Text Request