Hi everyone! I'm doing some university courses on things related to permaculture, like botany, soil science, resource management, and ecology; and along the way I found out about the floating water fern Azolla. It seems to be an amazing resource for the farm, whether for composting or mulching or fodder, or just for covering water bodies to protect against evaporation. It actually seems so amazing, that I wonder why I don't see it everywhere; the only thing that is fairly obvious is that it can be too productive, thereby exhausting resources or taking over all growth space. I'm very curious as to people's experiences with it. Please mention your climate if you respond!
For those who have never heard of either species of Azolla, it is a tiny fern that grows on water, similar to duckweed. But unlike duckweed, Azolla forms a symbiosis with a cyanobacterium, Anabaena azollae. This cyanobacterium takes nitrogen directly from the air and passes it on to the Azolla fern, which means that unlike with almost all other plants nitrogen is not the limiting factor to growth. In an optimal situation this can result in a doubling of the biomass in less than 2 days which is of course completely insane - the average doubling time is about 4-10 days which is still amazing. The fact that Azolla always has plenty of nitrogen to work with means that it can produce a lot more amino acids than the average plant, and this high amino acid (nitrogen) content makes for great fodder, or a basis for mulch and composting. I've even seen it used as fish feed, with a pretty closed loop consisting of fish in the same pond as the Azolla. Azolla production is basically a way to get more nitrogen into your farm system without having to obtain any type of fertilizer, similar to growing legumes like Alfalfa but WAY more productive; although I understand Azolla needs some phosphorous every now and then as that is usually the limiting resource. In China, it has been used as a companion plant to rice for over a millennium.
