The National Agricultural Research Center and Takata Engineering Corp. of Japan jointly developed technology for creating fertilizer that contains highly soluble silicic acid from rice husk ashes. They applied for a patent on October 13, 2004.
About two million tons of rice husks are currently produced every year in Japan, and 100 million tons around the world. These husks are burned as biomass fuel to generate electricity, but the problem remains of how to deal with the remaining ashes, which amount to 20 percent of the original volume. This new technology contributes to making effective use of these ashes.
When rice husks are burned at high temperatures, the silicic acid that accounts for over 90 percent of the ash becomes insoluble, precluding its use as a fertilizer. However, rice husks burned at low temperatures (around 500 degrees Celsius) make a useful fertilizer that contains highly soluble amorphous silicic acid. Applying this ash fertilizer to paddy fields increases the concentration of silicic acid in the soil, yielding a rich harvest of rice. This technology raises expectations for the effective use of both heat energy and rice husk ashes.
http://narc.naro.affrc.go.jp/narc-e/index.html
Posted: 2005/05/08 11:02:45 PM