About UNUMA HIDERO
About 北海道工開試
About TAKEDA SHOHEI
About 北海道工開試
About SAYAMA SOGO
About 北海道工開試
About ITO SABURO
About 北海道工開試
About 北海道工業開発試験所報告
About potash fertilizer
About citric acid
About Fertilizer manufacturing industry
About Other setting materials
About 塩化カリウム
About 石炭灰
About 原料
About 肥料
About 製造試験