Effect of Si soil amendments on As,Cd, and Pb bioavailability in contaminated paddy soils

Paddy and Water Environment - Numerous greenhouse and laboratory experiments have shown that the application of Si-rich materials may affect the mobility and transport of hazardous elements in the...     

Effect of Moisture Deficiency and Increased Salt Content on Silicon State of Some Soils of European Part of Russia and Central China

Soluble forms of silicon affect a number of physical, chemical, and biological soil properties. Optimization of silicon nutrition enhances plant tolerance to biotic and abiotic stresses. Current climate change and anthropogenic impacts can alter the soil silicon state. Model laboratory experiments conducted with upper horizons of sod-podzolic soil, gray forest soil under different plant associations, chernozem, paddy soil, and red subtropical soil showed that insufficient soil moistening led to a reduction in soil monosilicic acid by 15 to 36% and simultaneous increases in polysilicic acid by 9 to 45%. Soil cultivation resulted in a decrease in plant-available soil silicon. An increase in NaCl concentration in the soil caused an increase in both monomers and polymers of silicic acid by 6 to 79%. The mobile equilibrium and lability of the numerical values of the parameters of the silicon state of the soil–plant system are revealed. These factors should be taken into account when implementing the 4R-STRATEGY for optimizing mineral nutrition in agricultural crops.     

施用活性硅降低重金属移动性的研究

该研究通过一系列的土柱实验研究土壤中硅和重金属的反应机制。土柱实验在可溶性镉、铜、镍和铅酸盐的情况下,用各种活性硅（硅藻土,沸石,无定形二氧化硅,浓缩单硅酸）处理灰森林土。所有富硅物质都用电子显微镜测试分析过。富硅物质对土壤中重金属的钝化试验结果表明：硅藻土和浓缩单硅酸比沸石和无定形二氧化硅更能降低重金属的移动性。重金属移动性的降低是由土壤溶液中单硅酸和重金属的反应,以及富硅物质表面对重金属的吸附实现的。重金属在土壤中移动的强度与自身种类有关。施用富硅物质可明显降低镉和镍的移动性,对铜和铅的效果不明显。