School of Environmental Engineering, Toyama Prefectural University, Kosugi, Japan
Project Management Department, Vietnam National University, Hanoi, Vietnam
Purpose This study aims to evaluate the potential negative efects of rice husk as a source of fertilizer on plant growth. Methods Growth tests were conducted on komatsuna (Brassica rapa var. perviridis) using three types of experiment. A pot experiment was conducted to compare diferent fertilizers on an individual basis. A second pot experiment was conducted to compare diferent mixtures of fertilizers. Finally, a feld experiment was performed to determine the efects of the appli‑ cation of diferent quantities of silica. Results The results showed that komatsuna grew better with the application of silica mixed with fertilizer, and that there was an optimal quantity of silica to be used, when used on its own. It was found that, in all cases, the silica in the rice husk ash did not have any measurable negative efects on the growth of the komatsuna. Conclusions We, therefore, conclude that rice husk silica can undoubtedly be used for plant cultivation.