Study On The Effect Of Two Years Applying Fertilizer In Chinese Fir Plantations

Chinese fir is one of the most important timber species in China, as economy develops at full speed, the demand of timber increases unceasingly. The emergence of intensive management such as short rotation and full tree utilization brings out the fertility of Chinese fir plantations decline significantly, and impacts the timber production. In order to improve soil fertility, promote tree growth, achieve rapid growth and high-yield, a scientific measure of woodland fertilization is extremely important.Chinese fir is one of the most important timber species in FuJian Province. Most of the Fujian forest lands are the center of Chinese fir. This study was set up at 3 locations with three plot sites in each location in Fujian. These locations were topdressed in March 2007 and 2008. and Field investigation and laboratory analysis in the end of 2007 and 2008, The results showed :Ⅰ(1) 2–year-old forest land BaiSa forest farm: Topdressing NPK+Zn can accelerate the ground diameter growth obviously. After applying this fertilizer, Chinese fir's growth of the Ground diameter increased by 24% and 37%, respectively compared with the control; And applying NPK had an obvious effect on the increasement of tree height. After applying this fertilizer, Chinese fir's current annural tree height increment at 2007 and 2008 increased by 11% and 29%,respectively compared with the control. JiangLe forest farm: The best result of the growth of Chinese fir was top dressing NPK+Cu. Compared with the control , Chinese fir's Ground diameter and tree height at 2007 and 2008 with NPK+Cu fertilizer increased by 13%,38% and 36%,25%,respectively.(2) 3–year-old forest land JiangLe forest farm:The fertilization effect of NPK+Zn was the best amog fertilizations.Compare with the control, the current annural growth of dbh, tree height and stand volume at 2007 increased by 29%,31%,101%, and that at 2008 increased by 32%,26%,110%,respectively.YangKou forest farm: The fertilization effect of NPK+Cu+Zn was the best among fertilizations. Compare with the control, the current annural growth of dbh, tree height and stand volume at 2007 increased by 10%,9%,10.5%,and that at 2008 increased by 21%,13% and 28%,respectively.(3) 5–year-old forest land Topdressing NPK +Zn was optimum. the current annural growth of dbh, tree height and stand volume at 2007 were higher than the control, 22%,40% and 27.3%,respectively,and that at 2008 was higher than the control, 10%,20% and 17.8%,respectively.(4) 8–year-old forest land After applying the fertilization of NPK , the current annural growth of dbh, tree height and stand volume of Chinese fir at 2007 were higher than the control, 29%,6% and 4.3%,and that at 2008 increased by 20%,4% and 3.1%,respectively.(5) 12–year-old forest land All fertilization treatments to the influence effects of growth of Chinese fir were obvious.But to the stand volume, fertilizer treatment N50P100K50Cu25 was optimum. After applying this fertilizer, the current annural growth of stand volume at 2007 and 2008 were higher than the control, 20.2% and 11.5%, respectively.(6) 13–year-old forest land With topdressing PK as the best treatment. Compared with the control, the current annural growth of dbh, tree height and stand volume at 2007 increased by 38%,29% and 40%,and that at 2008 increased by 40%,31% and 44%,respectively.(7) 17–year-old forest land After applying fertilization of NPK , the current annural growth of dbh, tree height and stand volume of Chinese fir at 2007 were higher than the control, 13%,27% and 21%,and that at 2008 increased by 17%,31% and 27%, respectively.ⅡChinese fir's nutrient content of needles was generally higher than the control after application. After adding trace fertilizer, especially, the increase amplitude of Cu and Zn nutrient was more obvious.ⅢAfter applying fertilizer, the increase amplitude of soil nutrients was obvious too, Especially, the available nutrients.But the circulation of soil nutrients is complex, fertilizer efficiency is the result of continuous accumulation. Short-term changes in soil chemistry could not say that fertilizations had effective impact on soil properties, therefore, That relevant on the Effects of fertilization on soil nutrients to be studied further .