Skip to Content.
Sympa Menu

permaculture - Re: [permaculture] Growing algae in irrigation water?

permaculture@lists.ibiblio.org

Subject: permaculture

List archive

Chronological Thread  
  • From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: Re: [permaculture] Growing algae in irrigation water?
  • Date: Sun, 20 Nov 2011 23:44:41 -0500

On 11/19/2011 11:14 PM, Lawrence F. London, Jr. wrote:
On 11/19/2011 6:18 PM, Dieter Brand wrote:
Thanks Lawrence,

The shading from plants may reduce evaporation but that is probably
more than offset by transpiration via the leaves.

Dieter, my impression is that it might be good to look into that
further, transpiration figures for duckweed as opposed to direct loss
through evaporation, ratios and comparison with water conservation
figures for other schemes. Also the duckweed with reduce water
temperature thus reducing loss through evaporation. Google it.

"reduced evaporation in pond when surface is covered with duckweed"

I hit on the idea of trying to encourage algae growth in my
irrigation system because of something I read about high fertility in
some of the ancient cultures in which irrigation was used. It was
assumed that part of the fertility was due to the algae that would
form in the extended network of irrigation channels.

It sounds like a great idea. If you can grow azolla where you are then
that would be the aquatic plant of choice for accomplishing
nitrification of irrigation water.

DUCKWEED: A tiny aquatic plant with enormous potential for agriculture
and environment
http://www.fao.org/ag/againfo/resources/documents/DW/Dw2.htm
"Azolla, which is a member of the fern family grows extensively in
association with nitrogen fixing bacteria, which allows it to produce on
waters low in N but containing phosphorus. Azolla has been
comprehensively discussed by van Hove (1989)."

Another suggestion:

Obtain some Reemay or translucent woven synthetic fabric row cover used for crop cold protection. Grow duckweed in your water impoundment or tank(s) for added nitrogen or azolla or throw a little manure or compost in there and watch the algae grow. Cover the tank(s) with or without aquatic plants with Reemay to prevent most evaporation or loss through plant transpiration. Build a frame out of wood or plastic pipe
a little bigger than the opening of your tank; attach a section of Reemay to it; the weight of the frame will hold the Reemay in place over the tank while providing easy access to the tank for maintance, i.e. harvesting duckweed for animal feed or compost/fertilizer (high in nitrogen). There's a big plus to growing duckweed, you shade your impoundment, purify the water and produce high quality fertilizer.


LL




Archive powered by MHonArc 2.6.24.

Top of Page