土壤水分能量与兴安落叶松播种苗生长关系的研究

STUDY ON RELATIONS BETWEEN SOIL WATER ENERGY AND GROWTH OF SEEDLING PLANT OF LARIX GMELINI

为了研究兴安落叶松播种苗在出苗期、生长初期和速生期所需要的最佳土壤水分能量水平及影响生长的上、下限值,使用张力计控制3～4个土壤水分能量(土壤水吸力)水平等级(处理)。结果说明在出苗期对场圃发芽率、发芽势、平均发芽速度和 L/H 比的最佳土壤水分能量水平是土壤水吸力为10～20kPa;当土壤水吸力为50～73.3kPa 时,就严重影响出苗;当土壤水吸力低于10kPa 时,对苗木根系产生不利影响。在生长初期最佳土壤水分能量水平是土壤水吸力为30～40kPa;当土壤水吸力为10～20kPa 或50～73.3kPa 时,就明显影响苗木生长。在速生期对苗、地径、根系,生物量生长最佳的土壤水分能量水平是土壤水吸力为10～20kPa;当土壤水吸力为50～73.3kPa时。

The tensionmeters were used in this experiment to control 3～4 soil water energy(or soil water suction)level grades to study the optimum soil water energy level needed in the seeding stage,primary growth stage and accelerated growth stage by the seedling-plant of Larix gmelini and the upper,lower limit of the soil water energy influencing the growth.The experimental result showed that in the seeding stage the optimum soil water energy level(soil water suction)is 10～20 kPa for germination percentage,gemination potential,average germination speed and L/H ratio.The soil water suction seriously influences the seeding when it is 50～73.3 kPa,and when it is lower than 10 kPa it has a disadvantageous effect on plant root.The optimum soil water energy(soil water suction)level is 30～40kPa in the primary growth stage.The soil water suction seriously influences the plant growth when it is 10～20kPa or 50～73.3kPa.In the accelerated growth stage the optimum soil water suction is 10～20 kPa for the plant height,ground diameter,root and biomass increasing.The soil water suction will influence the plant growth when it is 59～73.3 kPa.