Fertilization Effectiveness and Gain Sustainability of Middle aged Pinus massoniana Plantation

Thirteen years' test of Pinus massoniana plantation fertilization showed that fertilizing P and K on red soil area benefited the growth of middle aged P. massoniana plantation and the effect of fertilizer lasts long, while applying N fertilizer was disadvantageous to the growth of plantation. The best combination of fertilizer was N1P3K2, i.e. the applying of N, P, and K fertilizers in the ratio of 0 kg, 240 kg, 65 kg per hectare. Taking P1 (0 kg per hectare) as control, P3 (240 kg per hectare) treatment will increase the periodic increments of tree height, DBH and volume by 6.1%, 15.0% and 12.7% respectively. In the certain stage after fertilizing, site quality will still be a factor closely correlated with the growth of P. massoniana. Fertilization will not promote the spatial differentiation of middle aged P.massoniana plantation.