Latest / Hydroponics Daily / Azolla: Hydroponic Marvel or Invasive Menace?

Transcript

Azolla: Hydroponic Marvel or Invasive Menace? · Hydroponics Daily

• 0:00
  Hello and welcome back to Hydroponics Daily, your go-to podcast for everything soilless cultivation.
• 0:06
  Today we're going to talk about the hydroponic cultivation of a remarkable plant
• 0:12
  and that is, it's not even a flowering plant, it's a fern.
• 0:15
  It's called a zola, you may have heard of it, you may have not.
• 0:19
  But it's a fern that
• 0:22
  grows in aquatic systems and
• 0:26
  it is extremely highly productive to the
• 0:29
  point where it can become an invasive plant if it gets
• 0:32
  into aquatic ecosystems and it
• 0:35
  is grown hydroponically around the world mainly as
• 0:38
  a fodder so an animal feed and
• 0:42
  because it grows so fast and because
• 0:46
  there's some unique features about azolla so it's
• 0:49
  a fern so it doesn't produce flowers or fruits so it's
• 0:52
  it doesn't waste energy on that but so everything goes
• 0:55
  into biomass it can produce it can double its
• 0:58
  biomass in just under two days
• 1:01
  if the conditions are correct so imagine that you can have
• 1:04
  a system that's just keep on producing biomass and
• 1:07
  biomass every two days that's more than enough to feed the
• 1:11
  animals if you've got a big enough unit it can the
• 1:14
  plant can yield eight to ten tons of
• 1:17
  fresh matter per hect in asian paddy fields now
• 1:20
  that's important because not only can that azolla be
• 1:24
  harvested away from the paddy field where
• 1:27
  rice is being grown it's also fixing nitrogen as
• 1:30
  well so it's adding nitrogen to the system because azolla one of
• 1:33
  the key features i've not mentioned is it fixes atmospheric nitrogen
• 1:37
  just like say a bean plant would and so.
• 1:40
  You're adding nitrogen to the system and that also means
• 1:43
  that you don't need to feed it nitrogen fertilizer
• 1:47
  sounds amazing doesn't it why is everyone not growing azola hydroponically
• 1:51
  the typical limiting factor in its growth is phosphorus and
• 1:54
  so you actually when you look at some of the azola hydroponic farms you'll
• 1:58
  find that they're often adding phosphate and super phosphate things like this
• 2:02
  forms of phosphorus and then they're also using in like in asia some sort of
• 2:08
  like the indian subcontinent they're using cow dung as cattle dung as the fertilizer
• 2:14
  and then adding a bit of phosphorus and,
• 2:16
  Interestingly, I read a report today as well that in Holland,
• 2:21
  they're recycling nitrogen and phosphorus from human waste, and that's going
• 2:26
  into hydroponic cucumbers.
• 2:28
  So not as, you know, might sound a bad dung, but they're using it in Holland
• 2:34
  and high-value greenhouses as well.
• 2:36
  So as I say, it's a weed in many parts of the plants.
• 2:40
  In many parts of the world, it's called a mosquito fern. but it does
• 2:43
  if it's contained is extremely useful as
• 2:47
  a as a fodder and it can be you the beauty
• 2:50
  of it is that the hydroponic systems can be very very
• 2:52
  simple you almost don't need circulation the
• 2:56
  deep water culture you don't need an
• 2:59
  air tank obviously this will improve production but you can literally just
• 3:02
  have a tank with fertilizer in and open
• 3:06
  to the air and just put some mozola in there some starting culture
• 3:09
  and it'll just grow and grow it's growing so fast that it
• 3:12
  doesn't really get any issues so it's
• 3:16
  fantastic if you're growing or you're if
• 3:19
  you're looking at a livestock in areas where you struggle with
• 3:23
  production of like grass or feed
• 3:27
  costs are expensive and feed costs are going up and
• 3:30
  up and up so solutions like this that can produce a product that's very high
• 3:35
  in amino acids because it's fixing its own nitrogen it can it can get the nitrogen
• 3:39
  required for the amino acids for the protein then it's a fantastic potential
• 3:42
  solution for this so since definitely something more people should be looking
• 3:46
  at because any type of livestock really can can use azolla.
• 3:50
  Don't think it's fit for human consumption though so especially if you're not
• 3:54
  using cow doing to fertilize it and just needs a quick rinse though for for
• 3:58
  animal feed so as i say it can be grown in these sort of shallow troughs or basins.
• 4:03
  If you google it you'll find these sort of 5 to 15 centimetres deep.
• 4:07
  No substrate required because the azolla floats on the surface, it's not like an algae.
• 4:11
  We talked about microalgae in the past and microalgae cultivation there,
• 4:15
  you know, sterilisation is everything.
• 4:17
  With azolla it doesn't need to be sterile at all, it just be open to the air.
• 4:20
  It does require fairly high temperatures though so
• 4:23
  that's why 18 to 28 degrees celsius and
• 4:26
  so below that you might get problems nutrient film
• 4:30
  technique you could use nutrient film technique or floating raft systems
• 4:33
  but after you could really that's for
• 4:36
  really large very large systems the
• 4:39
  key thing here is that the humidity needs
• 4:42
  to be fairly high so 60 to 80 percent humidity
• 4:45
  that's much higher than most hydroponic crops
• 4:48
  the things like the temperature and the ph of the
• 4:51
  fertigation solution they're all fairly standard
• 4:54
  obviously you don't need to add nitrogen to your
• 4:57
  system and it can um and that can be a good way of reducing the environmental
• 5:01
  impact of your hydroponic system and your animal feed system really is that
• 5:06
  you reduce completely eliminate the need for nitrogen so not sure on co2 enrichment
• 5:12
  what the effect that would have it's.
• 5:15
  Grows so fast and so quickly that it's thought that it would lead to an ice age.
• 5:20
  When Azolla really got going in, when was it?
• 5:24
  During the Eocene, so 56 to 36 million years ago, it fixed so much carbon that
• 5:32
  it triggered global cooling of this plant, this one plant.
• 5:36
  Azolla is a genus of seven species of aquatic ferns, but yeah,
• 5:41
  they were growing so fast 50 million.
• 5:44
  56 million years ago that it triggered an ice age that's
• 5:47
  some serious growth so yeah a couple
• 5:50
  of a couple of other amazing facts about zola it's
• 5:53
  called mosquito fern because in paddy fields it grows so fast and
• 5:56
  covers causes this blanket to appear on the surface
• 5:59
  that mosquitoes can't get into the
• 6:02
  paddy field and lay their eggs and cause larvae to
• 6:05
  grow so it's actually good at controlling mosquitoes in
• 6:08
  those systems or it's thought to and it can also be
• 6:11
  used to remove chromium nickel copper zinc
• 6:14
  and lead from wastewater effluent so
• 6:17
  in polluted areas you.
• 6:21
  Can potentially remove these nasty chemicals we
• 6:24
  had a leak of radio it was in the news today there's
• 6:27
  a leak of radioactive water up in scotland from
• 6:31
  a nuclear base but then that was
• 6:34
  in a lock and it was a saltwater lock so
• 6:37
  that would be no good in this situation because azolla would not tolerate it's
• 6:41
  a freshwater species so um of
• 6:44
  no good there but yeah potentially if you've got a river that's being
• 6:47
  contaminated with chromium nickel copper zinc and lead then you
• 6:50
  could potentially grow azolla in those systems
• 6:53
  to to mop up those those those metals so if you're interested in growing azolla
• 6:59
  for fodder you could be harvesting every three to five days serious amounts
• 7:04
  you need to harvest them often otherwise the growth the the plants will start
• 7:08
  to stagnate and you get die back and it starts to get stagnant conditions and it'll be a bit smelly.
• 7:14
  And you you might need to
• 7:17
  do something if it's an open outdoor system you might
• 7:19
  need to look at how you control how you keep the plants alive during
• 7:22
  the winter as well if you're in say europe or north america so
• 7:26
  as i say it can be grown on its own or to support
• 7:29
  other crops that might be growing in a sort of
• 7:32
  a deep water system like you know the rice in a
• 7:35
  paddy field but yeah something to look into azolla
• 7:39
  is also a just like a model plant species for
• 7:42
  ferns it'll be propagated by spores so you
• 7:45
  can't buy seeds of azolla your probably best bet
• 7:48
  is to just go and harvest some azolla from a pond make sure you know what you're
• 7:54
  looking for or speak to somebody who's already growing azolla for fodder and
• 7:59
  either ask them for a free sample or purchase a few samples i'm sure Or eBay
• 8:05
  probably has some Azolla for sale. Let's have a look.
• 8:08
  Let's go onto eBay and see what comes up.
• 8:12
  Let's type in Azolla. See how much Azolla's going to cost.
• 8:17
  I can buy some curtains. That's for £75. That's all right.
• 8:20
  Azolla as a feed ingredient. A paperback book for £45. I won't be doing that.
• 8:26
  Here we go. Duckweed Eliminator.
• 8:28
  Floating Pond Rake. Oh no.
• 8:31
  That's for killing Azolla where it becomes invasive.
• 8:34
  So maybe not. Maybe Azolla is so common that you don't need to purchase it.
• 8:42
  Just go to your local canal if you're in the UK.
• 8:45
  It's one of those ones that make
• 8:47
  canals look almost like lawn green or bowling green type look to them.
• 8:54
  So yeah, if you're interested in Azolla, if you've grown Azolla,
• 8:58
  let me know. I'd love to know your experiences.
• 9:00
  And I'm more than happy to feature your experiences on a future.
• 9:05
  Podcast episode. That's been 100 products daily for today. Thank you very much
• 9:08
  for listening. Until tomorrow, goodbye.