[permaculture] Rock Dust

Koreen Brennan cory8570 at yahoo.com
Fri Mar 8 06:28:06 EST 2013

I believe that minerals are key soil amendments in most cases. In so many areas, the soils have been demineralized. When rock dust is pulverized very fine, it is available faster. I use both seaweed and azomite. I've seen results with finely pulverized azomite in the first season with seedlings, without using much of it. I planted seeds in soil with rock dust and without and there was a definite difference in size and health of the plants. I would advise everyone who is not already doing so to test your products/soil mixes with seeds/seedlings - it's not a comprehensive test but the results are very easy to see. 

I'm using the course azomite with trees. The jury is still out on that - have not been doing it long enough to tell the difference.  I use a large handful per tree when I'm planting it, at the bottom of the hole. I have seen others get results with azomite or other minerals - healthier plants, plants that fruit when they were not fruiting before, etc. But they also added microbes, worm castings and fertility.  

I also use seaweed in sheet mulch, and the minerals are more available than with rock dust. I have had some plants burn when they hit a patch of concentrated seaweed, but some have had no bad response and are performing well.  I have several beds with different fertility and structure in them - goat manure, seaweed, biochar, horse manure, worm castings, hugulkulture, etc. So far, there is not much difference. The manure beds are doing slightly better and the worm castings are doing the best (no surprise). I just added biochar, jury is still out. 

Seaweed needs to be replaced yearly or regularly. In Florida, the nutrients can get washed through the sand into the nether realms. Course rock dust lasts longer, years or more - more stable. So putting both seaweed and rock dust in soils will give best of both worlds. 

A friend uses azomite and microbes in a rainbarrel to raise shrimp and they are doing great and the water stays clear. He also has tons of plants in there. This is all anecdotal stuff at this point, not enough controls in what I do to make it scientific.

The problem with all of these methods, the way I do them, is that they are inexact and get mixed results. It isn't the same as adding 3 cups of kelp, 2 of bone meal, etc, that organic growers use. I should probably try to do more of the "three cups vs one cup" thing and see what happens. I have students and volunteers coming through and they usually do something random to my garden when I'm not looking, though! 

The one thing I do that gets consistent great results immediately is to add pee to the garden. When I did that to plants that weren't doing well in mineralized soil (the soil itself was very crappy and dead soil - all I had at that time), the plants took off and started resisting pests, deep green leaves, fruiting well, etc. A few of my plants are very deeply healthy, stems, leaves, everything radiant and I feel this may be the overall mixture of soil, including minerals. The other ones may have not been there long enough for the mixture to kick in. I am installing a new system and am experimenting a lot with it, with the Florida soils, and will keep sharing as it progresses. I added minerals at Pine Ridge too last year so we'll see if there is a difference with the trees, this year. 
Koreen Brennan


 From: tanya <tanyagarden at gmail.com>
To: permaculture <permaculture at lists.ibiblio.org> 
Sent: Friday, March 8, 2013 1:23 AM
Subject: Re: [permaculture] Rock Dust
It's mostly a rant against the Rodale doctrine of compost and more
compost, and of compost as the answer to all soil woes. iirc he
recommends using a very small amount of compost after the first year
(as does Nauta, in fact) -- something like 1/4 inch to 1/8 inch or
less. Nauta talks about Elaine Ingham's rec, which comes to 1/90 inch.

Combined with that is a rant against Rodale for avoiding any mention
of Albrecht's ideas of balancing Ca and Mg so that they occupy 80% of
cation exchange sites

On Thu, Mar 7, 2013 at 10:08 PM, Chris Carnevale
<c.s.carnevale at gmail.com> wrote:
> Does Solomon have something against compost or does he just warn against
> using only compost and nothing else?
> Chris
> On Fri, Mar 8, 2013 at 12:38 AM, tanya <tanyagarden at gmail.com> wrote:
>> On Thu, Mar 7, 2013 at 8:32 PM, Chris Carnevale <c.s.carnevale at gmail.com>
>> wrote:
>> > Hi,
>> >
>> > I'm wondering who has used rock dust as a soil amendment and what your
>> > results were?  Has anyone found a better freely available micronutrient
>> > source?  How does seaweed compare to rock dust?
>> >
>> Haven't used it, but I recently read Steve Solomon's book on growing
>> nutrient-dense food, The Intelligent Gardener. He says mineralized
>> basalt rock dust is not practical for backyard gardeners because it's
>> expensive (to use the amount needed) and takes many years to show a
>> difference.  He analyzes what specific minerals you get (pounds of
>> each element per ton of rock dust) and looks at what other sources are
>> available. Instead of rock dust, he recommends sulfates from Black
>> Lake Organics for Fe, Mn, Cu, and Zn. They can be added to a dry fert
>> (based on the results of a specific $20 soil test from Logan Labs) or
>> used as a foliar feed (using a max of 1 tablespoon of single or mixed
>> sulfates per gallon of water; i teaspoon max for Cu). For
>> micronutrients such as Cr Co I Mb Se Sb V Ni   he recommends kelp meal
>> at 1 pound per 100 sf per year. For B he recommends regular laundry
>> borax, a teaspoon or so per 100 sf, depending on your soil test. (I
>> don't own the book but took a few notes.)
>> I'm in the middle of reading Phil Nauta's book on growing
>> nutrient-dense food, Building Soils Naturally. He does recommend rock
>> dust for everyone, but does not go into the details of what it
>> contains or how long it takes to see results. He recommends 2-50
>> pounds per cubic yard of compost so that it gets chelated with the
>> organic matter. For application directly to garden beds, he cites
>> other recommendations, which vary from 15 to 50 pounds per 100 sf, and
>> says as little as 0.5 lb/100sf has shown results. He also recommends
>> kelp meal, at 0.3-1 pound per 100 sf/yr. In addition, he also
>> recommends ocean water for some of the same trace minerals (and
>> recommends other additives that act as biostimulants), but again, does
>> not name the minerals.
>> Engineers will prefer the Solomon approach, very linear and
>> numbers-based, with detailed arguments for making each choice.
>> Kitchen witches will prefer the Nauta approach, lots of brews and
>> biostimulants.
>> The approaches seem quite different, but depending on your garden and
>> your goals, I think both approaches lend themselves to experimentation
>> and are complementary, for the most part. They do disagree on using
>> ferts with GMOs, and Solomon has a whole chapter about not relying on
>> compost.
>> If anyone else has read either or both of these books, I'd be
>> interested in hearing what you think. I've been thinking of getting my
>> soil tested (at a community garden plot) and playing around with more
>> than just the alfalfa pellets, nettle and comfrey teas, and compost
>> I've been using.
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