Study On Paulownia Seedling Varieties In The North Part Of Jiangsu Province

In this thesis, the author has investigated Paulownia nursery soil,self-protection to coldness,self-protection to wind.grow peculiarity of each varieties. The main results are described as follows:1 Paulownia nursery has reasonable soil physical and chemical properties.Their variety from soil deeps is equal to the intercropping soil of paulownia and crops.As the deeps is adding, the water content ,the manure factor is declining, the contents of soil organic matter, available P are grown. The contents of soil organic matter, the water content is the midium of the three sample.It is better to the pure copping soil ,is worse to the intercropping soil.It has reasonable manure factor, especially the available P, total P and total N are higher, they can supply enough manure. But the nersery of paulownia is thickness, as the seedling grown, more total P and total N must change to be available P and available N.2 Soil enzyme activities: soil enzyme activities reduced gradually from top to bottom layer of soil profile, but it is different tendency to the 4 varieties soil enzyme. intercropping soil and nersery .especially the nersery ,the soil is compact, it is bad to the soil enzyme activities3 In nersery, there existed close relationship between soil enzyme activity and physical, chemical properties, the main factors which affected the activity of invertase were the content of organic matter and PH value.The content of total N and available P had great effects on urease activity .The content of total N and total P affected the activity of alkaline Phosphatase greatly. The 4 varieties soil enzyme also existed close relationship to each other.4 Six varieties Paulownia have different peculiarity on exude rate of Potassium(K) and ion in different hypo-temperature.from synthesis evaluate,the self-protection to coldness is: baihua>26A>8B>sutong 3>maobai 33 >4A.baihua,26A have the same self-protection to coldness,are the best varieties;8B is the second,then is sutong 3,maobai 33,the last is 4A,have lowest self-protection to coldness.5 Six varieties Paulownia have outstanding different on crown structure outside and inside.6 paulownia can be divided to 3 types.a ia prtty crown as tower which has more and detailed branch; b is round or flat crown which has reasonable branches on quantity and size;c has more and big branches on top than bottom.maobai33, 8B, 4A are part of a type, sutong 3 is part of b type, maobai, 26 A are part of c type.6 The differnce on crown stucture is the important factor to the self-protection function to wind.To 4-year Paulownia, maobai 33 8B 4A have better self-protection to...