Objective  To study the growth of rice seedlings as well as absorption and transport of zinc (Zn) and copper (Cu) under different silicon (Si) application levels.

Method  ‘Wandao 71’ was used as material through water cultivation to study the biomass, zinc and copper contents and accumulation of rice seedlings under different silicon fertilizer levels of 0 (CK), 30, 60, 90, 120, 150 mg·L⁻¹, respectively.

Result  The leaf number, plant height and root length of rice seedlings were all higher than those of the control, and the biomass (fresh weight) of rice shoots and roots increased over the control by 5.44%−52.81% and 4.83%−42.49% respectively. The leaf number, plant height, root length and above-ground biomass were the highest in 90 mg·L⁻¹ SiO₂ treatment. Zn and Cu net absorptions of rice root increased over the control by 5.79%−77.43% and 6.51%−44.96%, respectively. The Zn transport coefficients of 60 and 90 mg·L⁻¹ SiO₂ treatments increased over the control by 10.91% and 38.18% respectively, meanwhile those of Cu increased by 8.70% and 26.09% respectively. The contents of Zn and Cu in rice shoot increased with the increase of SiO₂ concentration, reached the peak value at 90 mg·L⁻¹ SiO₂ concentration, and then began to decline with the increase of SiO₂ concentration.

Conclusion  Considering the factors of rice growth index, biomass, and absorption of Zn and Cu, 90 mg·L⁻¹ SiO₂ treatment is the best Si fertilizer level for microelements of Zn and Cu absorption in the present study.