Abstract: With solution culture, this paper studied the effects of silicon (Si) on the plant growth, Si content, photosynthetic rate, and transpiration rate of ginger (Zingiber officinale Rosc.) cultivar, Laiwu big ginger. The results indicated that the biomass per plant and the leaf Si content were increased dramatically with increasing Si level in culture solution. In treatments T₁ (1.0 mmol Si·L^-1), T₂ (1.5 mmol Si·L^-1), and T₃ (2.0 mmol Si·L^-1), the leaf Si content was increased by 604.4%, 834.8%, and 1130.4%, and the biomass per plant was increased by 9.4%, 19.4%, and 22.8%, respectively, compared with the control. With increasing Si level, the leaf Mg²⁺ATPase and Ca²⁺ATPase activities, photosynthetic rate (P_n), and water use efficiency (WUE) increased, while the transpiration rate (T_r) decreased. At 11:00 o’clock, the P_n in treatments T₁, T₂, and T₃ increased by 11.2%, 21.8%, and 28.2%, WUE increased by 23.1%, 55.9% and 54.8%, whileT_r decreased by 6.3%, 17.1% and 19.2%, respectively, compared with the control. Si also improved the leaf light saturation point (LSP), carboxylation efficiency (CE), and carotenoid content significantly, but had less effect on chlorophyll content. In our study, the suitable Si concentration for ginger was 1.5-2.0 mmol·L^-1.

Key words: swamp, drainage, swamp degradation evaluation, evaluation index system, Zoige Plateau.