Effects of planting density on growth of Sophora flavescens

200-day-old Sophora flavescens seedlings were transplanted into fields from greenhouse at different densities, including 2.50×105, 1.25×105, 0.83×105 and 0.63×105 seedling·ha-1 in March 2009, in order to explore effect of seedling density on growth of the plant. The experiment was randomly arranged with 4 treatments and each with 3 replicates (plot was 24 m2). Plants were measured in each month from June to October 2009, after transplanted. In total, dry mater of leaves, stems and roots increased with the decreasing of seedhing density. However, plants performed different in different months, in which some significant differences (P0.05) were found in leaf number, leaf fresh and leaf dry weight from July to October, leaf area, height, stem fresh weight, stem dry weight, root diameter, root fresh weight and root dry weight from August to October, and root length in August,among different treatments. Root weight of the density treatment of ≤1.25×105 seedlings·ha-1(68.9 g) was significant higher than that of the density with 2.5×105 seedlings·ha-1(41.2 g) (P0.05). This study indicated that 1.25×105 seedlings·ha-1 was the optimal density for the transplantation of S.flavescens.