Studies On The Rational Fertilizer Application To Poplar

Field experiment at shuyang and water cultivation experiment at the greenhouse are conducted to study the rational fertilizer application to poplar. The fertilization effect on the poplar seedling with different treatment, the nutrient peculiarity and vector analysis are studied. Meanwhile the fertilization effect on 3-year-old poplar, the optimum level of fertilizing (breast-height diameter, volume of timber) according to the regression equation and the economic benefits are analyzed through the field experiment. This research offers rational fertilization for poplar and it will promote the development of the poplar estate faster.The results obtained are showed as follows:1. The response of N, P, K to the length of main root is P>K>N and it is P>N>K to root biomass, but it is N>P>K to the young branch length, bark, branch, leaf and the total biomass. The treatment with high level of N (17.14mg/L), P (10mg/L), and K (8.58mg/L) significantly influences the growth of poplar.2. The optimum concentration of N, P, K to poplar according to regression equation are N: 13.68~14.59mg/L, P:2.12~2.52mg/L, K:1.71 ~3.10mg/L, and the corresponding total biomass is 21.71 g.3. The nutrient accumulation rule of poplar at different tissue is: leaf>root>branch>bark. The poplar with treatment of N, P, and K together absorbs and accumulates much more nutrition.4. It is showed from vector analysis: N, P and K are deficient in poplar unfertilized and they are limiting factors to poplar.5. It is showed from the field experiment: the treatment with high level of N (84g/tree), P(49g/tree), and K(42g/tree) is the most significant to poplar. The order of N, P, K effect is N> K>P.6. The optimum level of fertilizing to 3-year-old poplar is: urea:259.57g~287.48g/tree; superphosphate:490.00g ~ 569.50g/tree; potassium sulfate:65.83g ~ 66.36g/tree, and the corresponding optimization allocation is 12-6-3 or 12-6.2-2.7.7. After poplar is applied fertilizer, there are more amount of growing stock as 6.87m3 and much more 2061 yuan can be gained each hectare every year.