Study On Afforestation Technology Of Cutting And Burying Poplar Trunk And Its Effect On The Growth Of Plantation

In this paper,Ⅰ-107 poplar clones as the research object,the orthogonal experiment design was used to study the effects of stem length,stem diameter and soil type on the afforestation effect of Ⅰ-107 poplar and the changes of nutrients and related enzyme activities in the rooting process.The effects of different factors on the growth of poplar stem cutting and burying afforestation were studied,and the best combination of factors suitable for poplar stem cutting and burying afforestation was screened out,in order to provide technical support for Ⅰ-107 poplar stem cutting and burying afforestation technology;taking Populus × euramericana clone20 as the research object,the field afforestation experiment and analytic wood were used to compare the afforestation effect and the difference of poplar growth law under the conditions of dry cutting and burying afforestation,dry cutting afforestation and seedling afforestation.The main results are as follows :(1)The orthogonal test results showed that the order of the effects of different factors on the survival rate of Ⅰ-107 poplar cutting and buried afforestation was as follows : cutting length >cutting thickness > soil type.The optimal combination was as follows : cut-off length 120 cm+ sandy soil + cut-off thickness 3 cm.The cutting length has the greatest impact on the afforestation effect,and the growth and rooting indexes of young trees with 120 cm cutting length,such as seedling height,DBH,ground diameter and root number,are the best,which are significantly better than those with 40 cm cutting length.However,since there is no significant difference in the growth of tree height and DBH between 120 cm and 80 cm cutting length,80 cm cutting length can be selected as the cutting length considering the afforestation cost in actual production.The stem diameter mainly affected DBH and ground diameter,and the growth and rooting indexes of 3 cm-thick saplings were better than those of 1.5 cm and 4.5 cmthick saplings.Soil types only had significant indigenous effects on root length,and the average root length of sandy soil was better than that of clay and loam.Therefore,in practical application,it is recommended to select 80 cm cut and 3 cm cut and thick cuttings as the materials for cut and buried afforestation.(2)The soluble protein,starch and soluble sugar of three kinds of nutrients showed a trend of first decreasing and then increasing in the process of cutting and burying afforestation of Ⅰ-107 poplar.They decreased in the callus and adventitious root induction stage,and began to rise after developing into complete plants.Three kinds of rooting related enzymes polyphenol oxidase(PPO),peroxidase(POD)and indoleacetic acid oxidase(IAAO)change trend is not the same,in the process of rooting POD activity showed first increased and then decreased and then increased trend,IAAO and PPO activity showed first increased and then decreased trend.(3)The results of field experiments of colonization afforestation and seedling afforestation showed that the afforestation effect of clone 20 of Populus cathayana was better than that of seedling afforestation.The effect of stem-planting afforestation in the first year of afforestation was better than that of buried afforestation and seedling afforestation.In the second year,the tree height of buried afforestation was higher than that of stem-planting afforestation and the difference was significant.There was no significant difference in volume and DBH between buried afforestation and stem-planting afforestation.After the second year,the tree height and DBH of buried afforestation were significantly higher than those of stem-planting afforestation and seedling afforestation.Therefore,for specific poplar clones such as Populus cathayana 20,stem-cutting and buried afforestation was an ideal method for poplar afforestation.