The Siliceous, Si and Phosphorus, P

Si is a major element of earth’s crust and a main soils’ consistuent. Si content in soil varies from 1 to 45%, but it is non-soluble and is not bio-available for plants. It is found as silicate minerals, alumino-silicates and silicon dioxide. Beside it, Si is also sourced from silicon-rich materials of industrial wastes and plant biomass.