Study On Afforestation Technology Of Pinus Sylvestris Linn. Var Mongolica Litv In Yulin Sandy Land

Since new China was founded, people in Yulin sandy area have treated the sandy land in large scale. The took measures like growing grass, stopping sand and setting sand barrier to accelerate the development of pasturage industry in sandy land. However, the trend that"part is treated and the whole is getting worse"of ecological system in sand areas hasn't been changed in the foundation. The soil erbsion is serious, the sand area is enlarging constantly and grassland is being recluces. The area of sand is growing year by year. The diversity of biology has been destroyed seriously. The environment that is getting worse brings lots of damage to the develop ment of economy and socienty in sand area. Improving ecosystem, protecting the environment and acceleratmg the development of forest is the emergent and difficult tark if people want to live and develop. So it has great significarte to conclude and study the growing of evergreen coniferous tree-Pinus sylvestris Linn. Var mongolica Litv for improving the invironment in sand areas, treating soil erbsion and preventing the soil from becoming sand and at the same time, it is meaningful to the economic benefits, social benefits and eco benefits.This essay is mainly about the study on Xiaojihan forestry centre in Yulin which has a project called"Three-hundred-tree", and it combines theory with practice, uses comparison methods to do research on the key technology to improve the survival rate of Pinus Sylvestris Linn. Var mongolica Litv. The following are the results.1. The results of the experiment in dicates that the rate of emergence can be improved by 2.2% if the seeds are planted in loess. And the rate of conservation is improved by 17.2%. The young plant can grow by 1.7cm tall in the first year. After vernalization, the seeds can germinated earlier, farter etc. In comparison, it produces 4-6 days ahead of time. The rate of emergence is improved by 3.1% in half a month and the rate of conservation is improved by 11.9% a year later. Covering with the clean and small sand has great advantage over other covering materials such as field soil and loess. The emergence rates can be seperately improved by 8.2% and 11.6% and the time is 2-6 days and 2-9 days ahead of time. The two-year Pinus sylvestris Linn. Var mongolica Litv can get through winter safely by using rice straw and corn straw to cover them. The loss can be reduced by 3.96%. And it can save 1680 Yuan .So the most important measures to improve the quality of growing seedlings of (Pinus sylvestris Linn. Var mongolica Litv)in Yulin is to choose the rich soil carefully ,disinfect(消毒)seeds strictly, grow seedlings in greenhouse and use suitable materials to keep warm.2.The result of comparing the four different kinds of false indigo showed that 8m×24m size false indigo sand barrier had the best fixing sand effect when Pinus Sylvestris Linn. Var mongolica Litv row spacing was 4m×4m.This size of sand barrier not only fixed sand but protected Pinus Sylvestris Linn.Var mongolica Litv seedling and the survival rate of it was higher than 20m×24m size by 10.42%.Treated by plastic covering treatment, the survival rate of sand barrier Pinus Sylvestris Linn. Var mongolica Litv is as 97.0%,which is higher by 5.4% than covering with soil.By using soil water content of Driwater, survival rate of it reached 100 percent which is higher by 12% in comparison. Keeping water treatment can improve the survival rate by 45%, that is 95%,which is higher by 7% in comparlison. Of them, plastic covering treatment and keeping water treatment can make the survival rate as high as 100%.Besides,reducing the level, deep planting and plastic covering techniqu do great good to the survival of the plants. So the new technology of planting sand barrier afforestation, plastic covering afforestation, driwateric affoerstation, keep water afforeitation and ABT rooting powder afforestation do good to improving the planting technology of Pinus Sylvestris Linn. Var mongolica Litv in Yulin .Crowing seedlings of Pinus Sylvestris Linn. Var mongolica Litv,research on afforestation have very important meaning to solve the specific problems of troditional ways of growing seedlings. Besides, the further study on technology of growing Pinus Sylvestris Linn. Var mongolica Litv can play a very important part in preventing the soil from becoming sand, improving the eco system and the invest environment and the struction of balanced Yulin and eco Yulin.