COMPOUND AND MIXED FERTILIZER BASED ON SILICIC ACID AND PHOSPHORIC ACID

摘要

PROBLEM TO BE SOLVED: To provide a compound and mixed fertilizer based on silicic acid and phosphoric acid excellent in an elution property into soil and producible at a low cost.;SOLUTION: This compound and mixed fertilizer based on silicic acid and phosphoric acid is obtained by adding phosphoric acid to sodium silicate to gelatinize the silicic acid and drying as it is. As water-washing step is not carried out after the gelatinization, not only phosphoric acid but also soda (sodium) components are contained as they are in the solid matter. Therefore, the sodium dissolves into soil as sodium hydroxide because the sodium component exists at the compounding of a silicic acid-based fertilizer and a phosphoric acid-based fertilizer, thereby iron components in soil are inactivated as iron hydroxide. As a result, insolubilization of phosphoric acid by the iron components is prevented and at the same time, dissolvability in soil is enhanced by virtue of interaction between phosphoric acid and silicic acid.;COPYRIGHT: (C)2006,JPO&NCIPI