http://www.biologie.uni-hamburg.de/b-online/e34/34b.htm or more simply http://www.tilthproducers.org/tfia/nitrogen.htm
A few days ago I wrote <<does anyone know if algal strains exist that can
fix their own nitrogen from
the atmosphere -or would they need nitrogenous fertiliser added??>> without
Googling it. Well they do.
