Biomass and root: shoot ratio
The biomass was significantly (P < 0.05) influenced by the target species (T), soil nutrition condition (SNu), plantation condition (Pc) and their interaction (Table 1). The biomass of S. krylovii grown in mixture with S. grandis under high nutrition treatment showed the highest value (Fig. 1).
Only the factor of Pc significantly (P < 0.05) influenced the root: shoot ratio. The root: shoot ratio was lower inS. grandis - S. krylovii mixture system than that grown alone or in mixture with L. chinensis , and the value in mixture withA. cristatum showed no difference with that in any of the other three systems (Fig. 1).