Abstract:

To find out the effects of fertilization and fertilization time on the survival rate and tree growth of young Pinus massoniana, a study was carried out on the mountain red soil sites derived from granite at Fubo Experimental Farm of Experimental Center of Tropical Forestry of CAF, in Pingxiang city of Guangxi Autonomous Region from 1991 to 2002. The results showed that there was an evident influence on the survival rate of Pinus massoniana by fertilization Variance Analysis showed that there were extremely significant differences among the treatments. By means of Multiple Comparison, it was found that the survival rate of the young trees fertilized with NP, PK and NPK as basal fertilizers was significant lower than CK. Based on the 12 years' successively determined data, the growth curves showed that fertilization had long time effect on the growth of the young Pinus massoniana and the better treatments at the beginning would continue to maintain predominance in the end. Variance Analysis of the growth increment data observed for 11 years, showed that there were not significant differences among treatments except their stand volume. The effects of the different treatments on the growth of Pinus massoniana were different. The best fertilizer treatment was P₂(P₂O₅ :100 kg·hm^-2 ), in which the tree height, DBH and stand volume increased by 3.75%, 14.17% and 33.60% respectively than those of CK. The optimum time was P among all the time treatments, in which the tree height, DBH and stand volume increased by 3^98%, 27^57% and 45^76% respectively than those of CK. Furthermore, the stand volume of Pe treatment was significant higher than that of CK.

Key words: Pinus massoniana, Young stands, Effect of fertilization