Post-production Fertilizer Treatments Impact On Eucalyptus Robusta Growth And Economic Benefit Evaluate

E.robusta is a general term of the tree species of the Eucalyptus genus of Myrtaceae family.E.robusta can be used as protection forest and roadside trees,because of excellent characteristics of quick growth and high yield.It's famous material in paper-making industry.It has being introduced into China more than 100 years because of high economic benefits.Many researches analysis economic benefit focus on eucalyptus tree plantation,economic benefit of eucalyptus plantation through the cutting age,different clones,different fertilizing methods or different initial densities.In order to explore the difference fertilization treatments effect diameter?height and volume growth and selecting best time to top dressing,we select four years old eucalyptus as our experiment object in xintang,guangxi province.In our study,the main results are as follows:(1)The mean and variance of DBH analysis show that dressing fourth times in five years is better than other groups,but ANOVA Analysis show that there is no significant impact between fertilizer treatments.Even though there is no significant impact,but fertilizer treatments can increasing mean of DBH and reduce variance at the same time.It still has some economic benefit and reduces management cost.(2)The mean and variance of tree height show that dressing fourth times in five years is better than other groups,ANOVA Analysis show that different fertilization measures cannot achieve significant impact in growth height of trees.But mean of tree is higher than no fertilization and dressing fourth times in five years better than dressing fourth times in the four years old,fertilization can create better growth trend.(3)The mean and variance of DBH analysis show that dressing fourth times in five years is better than other groups,get same conclude with diameter and height.ANOVA Analysis shows that there is no significant impact between fertilizer treatments,but dressing can increasing mean of volume and reduce variance.(4)The analyses of growth and accumulation indicated that the dressing fourth times in five years was beneficial to increase average growth and accumulation.Dressing fourth times in five years lead to diameter increasing roughly 18.8%,height of tree roughly 22.4%and volume increasing 22.46%compare to no-fertilizer.Dressing fourth times in five years lead to breast diameter of height increasing 4.3%,tree height increasing 2.17%and volume increasing 1.4%compare to no-fertilizer.But ANOVA Analysis shows that there is no significant impact between fertilizer treatments.(5)The economic benefit analysis showed that dressing fourth times in the five years old is higher than dressing fourth times in the four years old and no fertilizer in net profit.Dressing fourth times in the five years old was relatively good in terms of economic benefits,and the net profit was 94,324.75 Yuan/hm2,which increasing the economic benefits by 4.62%compared with non-fertilizing.The net profit of dressing fourth times in the four years old was 90190.91 Yuan/hm2,and the economic benefit was improved by 0.83%compared with non-fertilizer application.The FNPV analysis show that dressing fourth times in five years old is 41397.09 Yuan/hm2,increasing 5.02%than no fertilizer;The FNPV of dressing fourth times in four years old is 39753.32 Yuan/hm2,increasing 0.85%than non-fertilizer application.