抄録
Solubility and crop response of potassium silicate fertilizer produced in the steelmaking process were investigated. Potassium silicate fertilizer contained potassium in slowly released form, which was made of the silicic acid in steelmaking slag and additional potassium carbonate. Tests with four potassium silicate fertilizers showed that the amount of water-soluble potassium (W-K_2O) was different although the amount of weak acid soluble potassium (C-K_2O) was almost equal. Increasing the W-K_2O of the fertilizers raised the solubility of potassium in distilled water and weak acid (2% ammonium citrate solution, pH 4.5). The dry matter production and amount of potassium uptake by crops were also related to increasing the solubility of potassium in weak acid solution. These results confirmed that the solubility of potassium in 2% ammonium citrate solution was important to decide fertilizer effectiveness. The response of crops to potassium silicate fertilizer produced with the steelmaking slag in terms of growth and dry matter production was as effective as commercial potassium silicate fertilizers. These results indicated that the potassium silicate fertilizer produced with the steelmaking slag could supply potassium and silicic acid in slow form to crops and increase the growth of crops.
