azolla as fertilizer and liferstock food

I read in a book that azolla would make a great fertilizer and livestock (duck) food. There are many different varieties of azolla and you can raise them in kiddy pools.
However; I'm not really sure how much azolla you can raise and if it's worthwhile the effort. If you need one kiddy pool for each garden bed then I would say it's not worthwhile.
We're getting -5°C (which is below freezing) in winter and I reckon the azolla would die. As I didn't see the plant in any waterway, would I have to purchase a new one each year?
Maybe I have to look a second time.
Anyone experience`?

Since Azolla levels increase pretty quickly I suspect that you could keep a 10 gallon tank in a souther window in the winter and just hold over inside like that. As I recall it needs a lot of phosphorus in the water, but it fixes nitrogen from the air thanks to a symbiotic relationship with some cyanobacteria in its root filaments. Since it's water borne fertilizer that you need this is probably the most appropriate time to use a product like a "super phosphate", which is Calcium Phosphate and will not build up undesirable salts in the system like other sources of phosphorus(manure) will.

very easy stuff.  would be very cheap to try it out, so the stakes are pretty low.  go for it.

And... if you go for it -

You could try placing the pool up against a south facing wall of a building and drape a couple layers of clear visqueen from the wall down over the pool (temp winter green house).  In addition you could paint the pool black (adsorb more heat) and add some small rocks or sand in the bottom to help.  Plus create a wind block.

I used the visqueen - south side tip over my tomato plants and was able to pick red ripe tomatoes past Christmas.  Your mileage may vary    Good luck!

The longest experience with azolla is in SE Asia (Vietnam, Thailand, etc) where it has been grown in the water in rice paddies along with fish, or in ponds where pig manure falls into the water, which feeds azolla and other water plants, which gets turned into fish and duck, and in the dry season, muck is taken from the pond bottom to fertilize fields. 


Might be useful in a grey water wetlands system... a wading pool or two to convert grey water into sweet water while catching sun and producing green biomass.

Is azolla superior to duckweed as a fish food?

Jami McBride wrote:
And... if you go for it -

You could try placing the pool up against a south facing wall of a building and drape a couple layers of clear visqueen from the wall down over the pool (temp winter green house).  In addition you could paint the pool black (adsorb more heat) and add some small rocks or sand in the bottom to help.  Plus create a wind block.

I used the visqueen - south side tip over my tomato plants and was able to pick red ripe tomatoes past Christmas.  Your mileage may vary    Good luck!

Man, I love this forum.  Such useful, practical information simply and freely given!

H Ludi Tyler wrote:
Is azolla superior to duckweed as a fish food?

Depends on the specie of fish you are trying to nurture. Tilapia seem to do poorly when azolla is added to their diet, while cichlids, carp and relatives do well on it.

http://www.fao.org/docrep/012/i1141e/i1141e02.pdf

Tilapia are a Cichlid.

H Ludi Tyler wrote:
Is azolla superior to duckweed as a fish food?

I don't know about their qualities as feed, but the two grow well together.  Lemna can use up a lot of nitrogen, which Azolla fixes, and both will absorb phosphorus.

Thanks 

Emerson White wrote:
Tilapia are a Cichlid.

Your right.

The literature on azolla and tilapia includes many studies that show a depression in growth and weight gain when azolla is added to the diet, sometimes even in small amounts. But some types of tilapia seem to do well on some types of azolla. And there are studies with other cichlids that I came across that show it is beneficial. 

Here is one survey of the literature that might be useful:
http://www.google.com/url?sa=t&source=web&cd=2&sqi=2&ved=0CB8QFjAB&url=http%3A%2F%2Fwww.fao.org%2Fdocrep%2F012%2Fi1141e%2Fi1141e02.pdf&rct=j&q=cichlid%20azolla&ei=m_uvTeGrI4altwfamN2ADA&usg=AFQjCNF0Lz-UX6EHaIhVr0DVR_cBYzs_Ow&cad=rja

So how can you harvest large quantities of the stuff???

We have a thick carpet if axolla on one of our ponds. It was started by a very small amount placed in the pond. It muktiplies very quickly and will soon form a thick mat which is easily scooped off with your hands or any kind of net. To overwinter it you could just put a small amount in a jar and keep it insde on a window sill. Then release it back into the pond in spring. We grew ours with a small amount if manure from the chook yard placed in the bittom if the pond. Nithing else was added and it went beserk.

Read about the "azolla event" for new respect.
http://en.m.wikipedia.org/wiki/Azolla_event