Study On The Effect Of Fertilization In Eucalyptus Grandis Pulpwood Timber

Study on the Effect of Fertilization in Eucalyptus grandis Pulpwood Timber Feng Maosong (College of Forestry and Horticulture, Sichuan Agricultural University, ya抋n, 625014) Abstract Using the design of quadratic common rotation including four factors, five levels, the basic models of efficiency were established between density, N, P, K and per area growth volume of 3.5 year Eucalyptus grandis pulpwood timber in naxi of luzhou, and the quadratic regression models were simulated closely with reality by testing. The results of principal-efficiency analysis, mutual-efficiency analysis and frequency analysis indicated: 1) Impacting per stand growth volume of Eucalyptus grandis pulpwood timber, the order of the four factors was as follows from the high to the low: density> P > N > K. The application of nitrogenous fertilizer and potash fertilizer hadn抰 better be over 8OgN?and 70 gN? Phosphate fertilizer must be mixed proper amount of nitrogenous fertilizer and potash fertilizer. 2) The combination high yield cultivated pattern When the four factors of density, N, P, K are in the confidence limit of 95% was the following: plantation density is 2460?490Nhm? N is 7h79 g扤? P is 96-400 gN? K is 32-67 gN? On basis of the exposition, per area growth volume of Eucalyptus grandis pulpwood timber may reach l54.8~484.2m3hm? Compared with the control (four factors adopt ? level) (62.85 m34inft) and the average current growth volume (96.75 a 146.3?93.l% and 60-90.4% growth rate with per area growth volume increase under the excellent cultivated pattern. 36 3) An obvious interaction did not exist between nitrogenous fertilizer and potash fertilizer. It is positive interaction marked between density and Phosphate fertilizer, but between density and potash fertilizer has remarkable negative interaction. Nitrogenous fertilizer and Phosphate fertilizer could exchange each other to a certain extent and it is mutually beneficial relation between Phosphate fertilizer and potash fertilizer. It positively increased per stand growth volume of Eucalyptus grandis pulpwood timber when it properly raised plantation density, enhanced the application of Phosphate fertilizer, decreased the application of potash fertilizer and improved the application of nitrogenous fertilizer considered the interaction between nitrogenous fertilizer and Phosphate fertilizer.