Abstract:

The characteristic of water consumption and water utilization efficiency of 20-year-old Pinus tabulaeformis and Platycladus orientalis plantation were studied by artificial irrigating. The results shown that there was positive correlation between the water consumption and irrigation.When the irrigation level were 1.5, 1.0, 0.5 time of precipitation and control, the water consurnption of Pinus tabulaeformis were 10 358.5, 8 290.5, 6 455.5, 4 337.0m³ ·hm^-2respectively, and Platycladus orientalis were 9 547.5, 7 980.0, 6 471.0, 4 195.0m³ ·hm^-2 respectively. Irrigation accelerated the growth of the trees. The hight, diameter at breast height and volume of Pinus tabulaeformis were greatly increased at the level of 1.0 time, and those of Platycladus orientalis were at 1.0, 1.5, 1.5 time. The water utitization efficiency of Pinus tabulaeformis and Platycladus orientalis were highest at the level of 1.0 time and 1.0～1.5 time respectively, and the suitale water of irrigation were 5 250～6 000m³ ·hm^-2 and 5 330～9 330 m³ ·hm^-2per tree respectively from March to October, which were divided into 3 times.

Key words: Pinus tabulaeformis, Platycladus orientalis, Characteristic of water consumption, Water utilization efficiency, Suitable irrigation amount