| Effect of Si fertilizer on Mn toxicity in acid soil was investigated by pot culture, in order to provide scientific basis for preventing Mn toxicity in acid soil. The results showed that there was significant rhizosphere effect in sugarcane including lower pH, available Si content and higher contents of active Mn, water soluble Mn, exchangeable Mn,organic chelated Mn, carbonate combined Mn, ferrimanganic oxidation state Mn in rhizosphere soil than those in nonrhizosphere soil. Further, the contents of active Mn, water soluble Mn, exchangeable Mn, organic chelated Mn reduced significantly under applying Si fertilizer (sodium metasilicate), but effects of Si fertilizer on Mn content and form in rhizosphere soil was lower than those in non-rhizosphere soil. Shoot Mn content (47.1~112.1 mg/kg) decreased significantly under applying Si fertilizer compared with no Si fertilizer application in sugarcane, and which decreased further with Si fertilizer application increasing from 0.5 to 2.1 g/kg. Although, shoot Fe content in sugarcane reduced along with Mn content reducing under applying Si fertilizer, the ratios of Fe to Mn increased from 2.92 to 5.72 in the treatments of applying Si fertilizer, which were significantly higher than that of control (2.51). Sugarcane plant height and total biomass under different Si fertilizer treatments increased by 4.07%~15.24% and 8.41%~28.03%. In a word, Si fertilizer can alleviate Mn toxicity in acid soil. |
