Metabolic Adaptation, a Specialized Leaf Organ Structure and Vascular Responses to Diurnal N Fixation by Sustain the Astonishing Productivity of Ferns without Nitrogen Fertilizer.

Sustainable agriculture demands reduced input of man-made nitrogen (N) fertilizer, yet N fixation limits the productivity of crops with heterotrophic diazotrophic bacterial symbionts. We investigated floating ferns from the genus that host phototrophic diazotrophic in leaf pockets and belong to the fastest growing plants. Experimental production reported here demonstrated N-fertilizer independent production of nitrogen-rich biomass with an annual yield potential per ha of 1200 kg N fixed and 35 t dry biomass.

Azolla domestication towards a biobased economy?

Due to its phenomenal growth requiring neither nitrogen fertilizer nor arable land and its biomass composition, the mosquito fern Azolla is a candidate crop to yield food, fuels and chemicals sustainably. To advance Azolla domestication, we research its dissemination, storage and transcriptome. Methods for dissemination, cross-fertilization and cryopreservation of the symbiosis Azolla filiculoides-Nostoc azollae are tested based on the fern spores.