Journal of Korean Society of Agricultural Engineers ISSN:1738-3692(Print) 2093-7709(Online) 한국농공학회논문집

In this study physical and chemical characteristics of rice straw ash (RSA) were analyzed in agricultural by-products such as the characteristics of soil pH, electric conductivity (EC), total phosphorus (T-P), available phosphate (Avail-P), and cation exchange capacity (CEC). The results showed that RSA is of mainly C in 95.74% and followed by Si > Al > P > Mg > K > Ca. The pH of RSA was high near 11 and the T-P concentration was 2,322.38±10.35 mg/kg. The specific surface area of RSA was 123.50 m²/g, which was much lower than that of biochar. The X-ray diffraction (XRD) analysis indicated that RSA were C and Si based crystalline. TCLP and KSLT test results implied that the heavy metal concentrations were below the environmental standards and would not impose the risks. T-P concentration increased from 225.59±12.69 mg/kg to 593.39±17.36 mg/kg along with RSA mixing ratio to soil from 0% to 15%. Both pH and EC values were increased with the increase of RSA ratio. The changes in Avail-P and CEC were not when RSA mixing ratio was 1%. whereas the Avail-P concentration was slightly increase when the mixing ratio was more than 5%. Additional investigation considering receiving soil characteristics based on the results of this study would help effective application of RSA to soil.