Influence of Ozone Treatment on Soil Nutrient and Acidity with Low Ozone Dose Rate

In this study, the influence of ozone treatment on physical properties of soil with low ozone dose rate was investigated. Ozone was generated by oxygen plasma using a dielectric surface barrier discharge and injected into soil in a quartz container which is rotated by a motor. The amount of soil used for the treatment was 100 g. Treating time was 1 min. The ozone dose rate, which is defined as ozone dose weight per unit weight of soil, was 0.1 %. Flow rate of ozone gas was 1.5 L/min. We measured the characteristics of soil such as inorganic nutrient contents (NO₃-N, NO₂-N, and NH₄-N), pH(H₂O), amount of fungi (nitrite and nitrate bacteria), amount of DNA of soil, and amount of exchangeable base (Ca, K, Fe, and Al) with low ozone dose. We measured physical properties of soil among three samples for confirmation of measurement reproducibility. Content of NO₃-N and NH₄-N increased slightly by ozone treatment for 1 min., and subsequently maintained at a constant value with time. The pH(H₂O) decreased just after ozone treatment. However, the pH(H₂O) value recovered gradually with time by the buffering function.