Subject: Re: Info needed: Kelp Tea Fertilizer
From: Robert Iuliucci <roberti@is.dal.ca>
Organization:
Date: Fri, 14 Aug 98 07:46:00
Message-ID: <MOD$980814.001@rec.gardens.ecosystems>



At 04:54 PM 11/07/1998 -0700, you wrote:
>Mr. Luliucci,
>
>thank you for reading this note:
>
>I am in need of some advice. I have just converted
>a 55 gallon storage drum into a valved container to brew some kelp
>based fertilizer. May be I should explain a bit.. I run a small native
>plant nursery here in Monterey, California. All plants are not sold but
>used for local restoration
>projects in the Monterey Bay area, and for native plant gardens at
>local schools. I have been looking into running a more organic and
>sustainable system here for some time. Having completed a composter, I
>am now looking at taking advantage of the coastal ecosystem which I
>would like to bring into the loop here at our modest greenhouse.
>Basically my plants and I our looking for an alternative to the
>petro-chemical fertilizers we've employed in the past. We hope you can
>help.
>
>a few questions.
>
>1. Should I be worried about the salts in the Kelp tea, there has been
>some
>caution and concern that with our hard water from the tap, that any
>more salts
>in our water will lead to problems, what do you think?
>
>2. If we go forward with this project, how much kelp should be used when
>making the brew? Is there a 'kelp to water ratio'.
>
>3. How long should the brew 'steep' for?
>
>4. And finally at what ratio would be best for a dilution to apply to my
>hungry plants?
>
>
>Drew -

About 20 years ago I researched using a seaweed solution for commercial
greenhouse application but didn't follow through on it mainly because
startup costs were high (I didn't have a greenhouse) and if it didn't work
out I'd land in the poor house. At the time the market for organic produce
in Nova Scotia was almost non-existent so probably it wasn't a very
practical scheme. What was surprising is that I was encouraged by a
provincial government greenhouse horticulturalist who thought that
scientifically the idea had merit. I haven't done any recent work but I'm
sure someone has and that a net-search on nutrient film technique (nft) or
"soilless" growing or seaweed extract should yield some results.
I have used leachate from my composting operation in my home-use greenhouse
with excellent results. I'm not consistent enough in its use or production
oriented so can't comment on its effectiveness relative to using other
solutions.
Re: your questions - basically you'll have to experiment and adapt to your
conditions. (1) I don't know how hard your water is but if the addition of
kelp brew puts you over the edge you should probably be adding something to
adjust your pH now. (2) I'd say stuff the drum with seaweed and add water to
fill. I wouldn't bother shreedding or chopping the kelp but you could to
improve surface area exposure. Top up the drum periodically or as you use
tea until kelp is exhausted. It might help to stir or pound the mixture.(3)
Are you planning on applying something other than solar energy to heat the
brew? I wouldn't but if you do it'll drastically reduce the steeping time.
(4) This would depend on how long you let the solution steep and
concentrate. Applying a weak brew full-strength shouldn't hurt. Unless
you're set up to analyze the mixture you're just going to have to guess and
learn from observation how to use it.
A local marine biologist who works on seaweeds talks about the leachate as
SLS - "sewage like substance". No doubt about it, raw and fully-composted
seaweed are pleasant to be around, but actively decomposing seaweed exudes
eau de septic tank. Family, neighbors, and greenhouse workers will greatly
appreciate your siting of the tea drums well downwind of their location.
Good luck, Bob Iuliucci - Bear Cove Resources