Growing Azolla to produce sustainable protein feed: the effect of differing species and CO concentrations on biomass productivity and chemical composition.

Background: Since available arable land is limited and nitrogen fertilizers pollute the environment, cropping systems ought to be developed that do not rely on them. Here we investigate the rapidly growing, N -fixing Azolla/Nostoc symbiosis for its potential productivity and chemical composition to determine its potential as protein feed.

Results: In a small production system, cultures of Azolla pinnata and Azolla filiculoides were continuously harvested for over 100 days, yielding an average productivity of 90.