A Preliminary Research on Fertilization Tests of Young Plantations of Szemao Pines

8 fertilization modes plus a control test were implemented in this paper. The test results showed that the 9^th fertilization mode N3P3K2 (250 g + 400 g urea superphosphate + 100 g potassium sulfate) should be selected for young Szemao pine plantations. As compared with on use of 9^th fortilization mode the average tree height, DBH and volume (initial planting density:1 m^* 2 m,2 m^* 3 m) of the young plantation were separately enhanced by 29.14% and 48.64%, 18.1% and 23.3%, 74.14% and 106.25%. The best fertilizing time should be generally selected in May and June.