This paper summarizes the theory of the chemical and physical properties of Si, soil classification for Si soil test and Si fertilizer types, effect of Si fertilizer on plant and soil etc., and proves that Si fertilizer can increase the P nutrition, yield and quality, resistance to any biotic and abiotic stress ability, reduce the toxici- ty of heavy metals of plants and improve the water fertilizer retention of soil by practice; also points out that the best source for Si fertilizers is natural rich Si ma- terials. At last, it gives the prospection about the application of Si fertilizer in the sustainable and organic agriculture.
