Abstract: Experiment was conducted with potted seedlings of Rosa rugosa，for studying the effect of soil compaction with 1.10 g · cm-3，1.30 g · cm-3，1.50 g · cm-3 soil bulk density（SBD）on growth and root nitrogen metabolism of the seedlings. The results showed that the values of growth index and biological yield under different soil compaction were 1.30 g · cm-3 > 1.50 g · cm-3 > 1.10 g · cm-3. The ratio of root/top （R/T）of plant was decreased with soil compaction increasing，and the R/T of the 1.50 g · cm-3 SBD was significantly lower than that of the 1.10 g · cm-3 and 1.30 g · cm-3 . The root growth of the potted seedlings were inhibited as the soil compaction increasing，including root length，lateral root number and tap root iameter，but the average diameter and surface area of root was increased. The root activity，NO3--N and NH4+-N contents，NR activity in root were the largest in the 1.30 g · cm-3SBD，then the 1.50 g · cm-3 SBD and the 1.10 g · cm-3 was the lowest. GS activity in root was increased as the soil compaction increasing. The experiment indicated that the soil compaction was a crucial factor to affect nitrogen metabolism and influence the absorption and utilization of nutrients in plant. 1.30 g · cm-3 SBD was favorable for plants to grow.

Key words: Rosa rugosa, soil compaction, root architecture, nitrogen metabolism