How much oyster and gypsum to add

Greenthumbs256

Well-Known Member
OK guys I been working on this for a while I'm starting to cook and re amend my old soul today. I added a few things I already had and have been using yesterday. From a few of your guys help I picked up neem meal, gypsom , and oyster shell. I'm not sure on how much to add. Below is a list of everything I've added already and how much. Lil info about my soil I have roughly 3 cu ft of soil in a 50 gallon tote. It consist on some happy frog, ffof , perlite, and tons of ewc and compost from over the years. I'm gunnar cook it for at least a month. I plan to add another bag of ewc and perlite before using and potting this soil. Thanks for all your help guys I've learned a lot from quite a few of you. Thanks I wouldnt be here without yall.
2 questions

1 how much neem, gypsom, and oyster shell should I add.

2 do I need add more of any of my already added amendments, like maybe more kelp or alfalfa?
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Richard Drysift

Well-Known Member
I would add in about 1/2 cup of gypsum to 4 cu ft of soil. Oyster shell takes forever to break down so you can be more generous; I would add a cup or 2. Neem meal I would add in a cup. I try to give even amounts of everything but you certainly do not need to be deadly accurate. it's better to have lots of inputs in low quantities than a whole lot of one thing. That goes for everything except compost; go nuts with that. I wouldn't add much else looks like you've got it all pretty much covered.
 

Greenthumbs256

Well-Known Member
I would add in about 1/2 cup of gypsum to 4 cu ft of soil. Oyster shell takes forever to break down so you can be more generous; I would add a cup or 2. Neem meal I would add in a cup. I try to give even amounts of everything but you certainly do not need to be deadly accurate. it's better to have lots of inputs in low quantities than a whole lot of one thing. That goes for everything except compost; go nuts with that. I wouldn't add much else looks like you've got it all pretty much covered.
Thanks so much buddy you have been a great help. I'll keep everyone updated on how this run goes.
 

Wetdog

Well-Known Member
Is this oyster shell "flour", or just crunched oyster shell, like for chicken scratch? The 'flour' should have the consistancy similar to flour used for baking (mesh size). I used the chicken scratch stuff once and it had not broken down a bit 3 years later. Pretty much useless in a soil mix. But I see you also have dolo, so you're GTG there.

For the gypsum, it's between 1/2 to a full cup/cf, depending on what's going in the mix. But starting light as Richard suggested is the smart thing till you gain experience with it. It's good stuff.
 

MistaRasta

Well-Known Member
No such thing as too much Calcium.

No such thing as too much Sulfur either.

http://www.spectrumanalytic.com/support/library/ff/S_Basics.htm

I'd throw in a Cup per cubic foot. It's only going to help..

You don't need the oyster shell if using dolomite lime and vise versa.. they're both there to add Calcium in Carbonate form so as to move the ph.. move it too much and you're going to have problems.

And I'd only throw in a 1/2 cup of lime per cubic foot, you're going to have all kinds of Cations from that list contributing to a rise in ph..
 

im4satori

Well-Known Member
if your ph is already in range and your not adding any acidic amendments such as peat or pine bark would it be necessary to add lime? why not just add the 1 cup gypsum per cubic ft and not add any lime?

again, that's assuming the soil your starting with is already roughly neutral why add lime?
are you watering with rain water or tap water?

im asking as a question, the above remarks are questions, not statements.....
 
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green_machine_two9er

Well-Known Member
if your ph is already in range and your not adding any acidic amendments such as peat or pine bark would it be necessary to add lime? why not just add the 1 cup gypsum per cubic ft and not add any lime?

again, that's assuming the soil your starting with is already roughly neutral why add lime?
are you watering with rain water or tap water?

im asking as a question, the above remarks are questions, not statements.....
I don't add any lime. Oyster. Gypsum. Crab plus peat is usually pre limed. Ice always heard dolomite can break down over time with the wrong % of ca to mg. Causing lockout. Maybe someone else can verify this.[/QUOTE]
 

Wetdog

Well-Known Member
if your ph is already in range and your not adding any acidic amendments such as peat or pine bark would it be necessary to add lime? why not just add the 1 cup gypsum per cubic ft and not add any lime?

again, that's assuming the soil your starting with is already roughly neutral why add lime?
are you watering with rain water or tap water?

im asking as a question, the above remarks are questions, not statements.....
Because gypsum is the wrong form of Ca to affect pH, being Ca sulfate. Lime, oyster shell, Ag lime are all Ca carbonate that does affect pH.

You can get by with just using a Ca carbonate for both pH and as a Ca source, gypsum would not do this 'double duty'.

Even starting at neutral, organic mixes tend to the acidic because of decomposition and microbe activity.
 

Wetdog

Well-Known Member
I don't add any lime. Oyster. Gypsum. Crab plus peat is usually pre limed. Ice always heard dolomite can break down over time with the wrong % of ca to mg. Causing lockout. Maybe someone else can verify this.
[/QUOTE]

*I* can't verify if what you heard is Bro science, internet myth, or stoner science, but can say that it is incorrect information, especially when it comes to our container mixes.

You would think after several hundred years of use (whenever the machinery for pulverizing rocks was developed), farmers would have noted these lockouts. But yet, it's still in common use, at least in my area of SC.
 

Greenthumbs256

Well-Known Member
if your ph is already in range and your not adding any acidic amendments such as peat or pine bark would it be necessary to add lime? why not just add the 1 cup gypsum per cubic ft and not add any lime?

again, that's assuming the soil your starting with is already roughly neutral why add lime?
are you watering with rain water or tap water?

im asking as a question, the above remarks are questions, not statements.....
Question one I don't check my pH any more every has always said in organics it's pointless over the last 2 years haven't had any major issues that couldn't be fixed with a tea or foiler spray.

Question 2 I use ro water most of the time sometimes I add cal mag to substitute what the water is missing.
 

MistaRasta

Well-Known Member
Oh Cal mag..

Why would I want Carbonates treated with Nitric acid going into my soil? I can understand sulfates, but Nitric acid?

1 Gram of Gypsum works out to around 20 ppms of Calcium per Cu ft of soil and I see results in around 2-3 days. Shorter if I hit with fulvic acid.
 

Buba Blend

Well-Known Member
I don't add any lime. Oyster. Gypsum. Crab plus peat is usually pre limed. Ice always heard dolomite can break down over time with the wrong % of ca to mg. Causing lockout. Maybe someone else can verify this.
The site MistaRasta gave above in the Magnesium section, might have some useful info on ratios of ca to mg. Nice read, I added it to my list of saved sites.

In the Balances and Ratios section:
According to Dr. Stanley Barber, Purdue Univ., “There is no research justification for the added expense of obtaining a definite Ca:Mg ratio in the soil. Research indicates that plant yield or quality is not appreciably affected over a wide range of Ca:Mg ratios in the soil.”
There is more here:
http://www.spectrumanalytic.com/doc/library/articles/mg_basics
 
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