2025 Volume 67 Issue 2 Pages 43-49
This study investigated the impact of wood ash application on soil chemical properties and the growth of nursery-reared potted hinoki cypress (Chamaecyparis obtusa) seedlings. Bottom ash (10 g) derived from wood biomass combustion was mixed with approximately 2 kg of wet soils and applied to each seedling pot as a first treatment; then, the additional bottom ash (10 g/time) was applied to surface soil on the pots for another five times.
The analysis of soil chemical properties revealed higher pH and electrical conductivity values as well as higher concentrations of exchangeable base cations (such as Ca, Mg, and K) in the group subjected to the first wood ash application than in the respective control group. The additional five applications resulted in significantly higher soil pH values and exchangeable Ca and K concentrations but significantly lower total carbon (TC) and total nitrogen (TN) concentrations in the surface soil (depth, 0-5 cm), while only exchangeable K and TN concentrations varied below a depth of 5 cm, being significantly higher and lower, respectively. Therefore, the impact of additional ash application on soil chemical properties may be limited to the surface soil down to a depth of 5 cm, except for exchangeable K.
The application of bottom ash at a weight ratio of approximately 6% did not result in significant differences in the main axis length, diameter growth, or biomass of hinoki cypress seedlings between the treatment and control groups, indicating a limited impact of such dosage on seedling growth.
