Organic hydroponics, developed in NARO, Japan, is a useful and practical hydroponic technique using organic fertilizer.
A conventional hydroponics cannot use organic fertilizer because there are few microorganisms for degrading organic compounds, so organic compounds become rot and the humic substances inhibit the root growth.
Therefore, organic fertilizer can be used only for soil culture. It cannot be used for soil-less culture, for example hydroponics.
But Makoto Shinohara, a NARO researcher, developed a technique that microorganisms degrade organic compounds to inorganic nutrients in water, so called 'multiple parallel mineralization (MPM)'.
Organic nitrogen contained in organic fertilizer is degraded to nitrate via ammonification and nitrification in soil, but in water, degraded to ammonia because nitrification is inhibited.
Nitrifying bacteria resiponsible for nitrification is susceptible to organic compounds, so exposure of amounts of organic compounds inactivate or kill nitrifying bacteria.
The MPM technique protects nitrifying bacteria against exposure of organic compounds and makes it possible to proceed ammonification and nitrification in parallel in water.