The advance in research of silicon nutrition of higher plants

The earth's crust contains about 27.6% of silicon, but main form of silicon is silica dioxide(SiO_(2)). There are only 50--250 mg/kg of available silicon in soil that can be absorbed by plants.The soil can keep the concentration of silicon in soil solution to a constant level even after plants took it up.Silicon mainly deposits in the cuticular cells and cell wall of plants in the form of SiO_(2)·nH_(2)O. Silicon content in plants varies greatly with plant species and plant parts orgasm of the same plant, cultivation methods and environmental factors affect silicon contents. Plants absorb silicon mainly in the form of mono-silicic acid. The ability of silicon absorption varies obviously with plant species. Rice can uptake silicon actively and most of other plants uptake silicon passively. Silicon can affect plant's morphology and uptakes of other elements, and improve photosynthesis and respiration, which contributes to lodging and draught-resistance. higher silicon contents in plant can control bourgeoning of epiphyte spore and hyphal growth. The application of silicon fertilizer can improve the plants resistance to disease and pest and thus decrease the occurrence of them.