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Advice for soil amendment decomposed granite

Ur Humbl Nr8tor

Well-known member
Veteran
Working with an outdoor plot. Decomposed granite, primarily. Area has grown primarily citrus & avocados for 30+ years. I’ve dug out multiple 50 gallon holes and need to amend the soil. Limited organic resources right now because of Covid-19. I plan to mix in 30% (15 gal) compost. How does that sound? I’ll also be adding in a pellet organic vegetable food at recommended strength. Any other suggestions? Thanks in advance!
 

Rico Swazi

Active member
pics of the lay of the land as it sits now would be helpful but not needed if you can describe the soil properties well enough but pics always help.

Have the citrus and avocado trees been removed because of disease ? any mulching material on the ground? Can you get cover crops going?

If the trees were healthy I would plant right in the ground,top dress with compost, mulch heavily and save the digging for gold (granite iron pyrite joke):biggrin:
 

Ur Humbl Nr8tor

Well-known member
Veteran
pics of the lay of the land as it sits now would be helpful but not needed if you can describe the soil properties well enough but pics always help.

Have the citrus and avocado trees been removed because of disease ? any mulching material on the ground? Can you get cover crops going?

If the trees were healthy I would plant right in the ground,top dress with compost, mulch heavily and save the digging for gold (granite iron pyrite joke):biggrin:

Holes are dug. About 50gallons each. Sloping hill side. Avocados and citrus are healthy. 30+ year old grove. Shovel and my back is what it took to dig out each of the six holes. Plan to amend with 30% compost and some granular vegetable nutrients. Maybe mycorrhiza and a little chicken/cow manure. Let it cook till end of the month and plant in.

picture.php
 

Rico Swazi

Active member
Thanks. looks like great drainage. Are you using gypsum on the trees? What other ferts have you been using on the trees and surrounding area? Any soil tests over the 30 yrs? Must be doing something right as they are healthy.

planting clones? If you would like to know if all your work digging and the cost amending holes was worth it .... take one cutting and plant it in the ground next to some healthy weeds. See if your native mycorrhiza performs as well as what you put in the holes. A layer of gypsum for calcium under compost under minimal 3 inch mulch and let it grow.


if you are into experimenting that is.



If not, its okay with me, your plan sounds good since you have healthy trees you know what is what when it comes to your soil. IME many growers have been surprised at the results of planting straight to the ground.


last thing, if you do the test, you don't have to take your best cut, but to keep it fair, not the worst either
Now's the time for me to chillax sit back and listen to what the others have to say
Good luck in every way growin more TREES where there weren't any before :tiphat:
 
T

Teddybrae

Man, some of my soil is Decomposed Granite. Ancient riverbed, actually. Quite rich in its own right.

Yeah, do the Compost. And thoroughly dig in Chicken shit. A little more than the instructions on the bag say.

Get a Soil pH Test Kit. Cheap. pH your final mix then keep testing after you've watered everything in and decomposition has started. (like yr manure will acidify the soil which is probably a little too acid anyway.)


You'll probably need Dolomite. It will adjust your pH UP (to a higher number) and has Calcium AND Magnesium for your plants.

If you don't add enough now, you can always top dress and also foliar spray later in the season.

Good luck!
 

St. Phatty

Active member
Working with an outdoor plot. Decomposed granite, primarily. Area has grown primarily citrus & avocados for 30+ years. I’ve dug out multiple 50 gallon holes and need to amend the soil. Limited organic resources right now because of Covid-19. I plan to mix in 30% (15 gal) compost. How does that sound? I’ll also be adding in a pellet organic vegetable food at recommended strength. Any other suggestions? Thanks in advance!

de-composed granite is like Concrete when it dries.

i've been planning a barn or workshop using de-composed Granite. Why pay for concrete when you have 15 acres of natural concrete ?

i suggest mixing it, 1 part de-composed Granite, 2 or 3 parts other stuff to "chill out" the de-composed Granite, so it becomes a normal mixer like sand.
 

Ur Humbl Nr8tor

Well-known member
Veteran
Thanks. looks like great drainage. Are you using gypsum on the trees? What other ferts have you been using on the trees and surrounding area? Any soil tests over the 30 yrs? Must be doing something right as they are healthy.

planting clones? If you would like to know if all your work digging and the cost amending holes was worth it .... take one cutting and plant it in the ground next to some healthy weeds. See if your native mycorrhiza performs as well as what you put in the holes. A layer of gypsum for calcium under compost under minimal 3 inch mulch and let it grow.


if you are into experimenting that is.



If not, its okay with me, your plan sounds good since you have healthy trees you know what is what when it comes to your soil. IME many growers have been surprised at the results of planting straight to the ground.


last thing, if you do the test, you don't have to take your best cut, but to keep it fair, not the worst either
Now's the time for me to chillax sit back and listen to what the others have to say
Good luck in every way growin more TREES where there weren't any before :tiphat:

I may give that a try, Rico. Just to see what comes of it. I’ve got a number of plants from seed that I will be cloning out to put into each of the holes. I backfilled with native soil and 30% compost yesterday. I’ll top dress with a little manure and the organic pelletized veggie fertilizer. Mykos got delivered today.

This grove hasn’t been fertilized in years. We finally put some down and plan to amend several times this season. The drainage is hella good. If anything, I’m hoping the compost and 3-4 inches mulch will help with moisture retention. it gets hot as hell in the summer. I’ll add some gypsum as well. Here’s some more pics.


picture.php



picture.php


picture.php
 

Ur Humbl Nr8tor

Well-known member
Veteran
Man, some of my soil is Decomposed Granite. Ancient riverbed, actually. Quite rich in its own right.

Yeah, do the Compost. And thoroughly dig in Chicken shit. A little more than the instructions on the bag say.

Get a Soil pH Test Kit. Cheap. pH your final mix then keep testing after you've watered everything in and decomposition has started. (like yr manure will acidify the soil which is probably a little too acid anyway.)


You'll probably need Dolomite. It will adjust your pH UP (to a higher number) and has Calcium AND Magnesium for your plants.

If you don't add enough now, you can always top dress and also foliar spray later in the season.

Good luck!

Thanks Teddy. I’ll figure out a way to do a cheap pH. When this Covid shit dies down, I’ll spring for a professional analysis. I will adjust the soil via top dressing if need be. I need to check the pH of the water as well. I’m guessing it’s high 7’s to 8.
 

Ur Humbl Nr8tor

Well-known member
Veteran
de-composed granite is like Concrete when it dries.

i've been planning a barn or workshop using de-composed Granite. Why pay for concrete when you have 15 acres of natural concrete ?

i suggest mixing it, 1 part de-composed Granite, 2 or 3 parts other stuff to "chill out" the de-composed Granite, so it becomes a normal mixer like sand.

There is definitely sand in the mix already. I was able to dig the 6 50gal holes by hand in under 4 hours. I talked to the head honcho at one of my favorite nurseries. He suggested 2 parts DG, 1 part compost. Don’t want the roots to be too spoiled when they hit the pure native soil. Toughest part was the last two holes because of oak tree roots.
 

h.h.

Active member
Veteran
A hole with amendments can be like growing in a pot. Top dress and side dress.
 

Ur Humbl Nr8tor

Well-known member
Veteran
I took 3 soil samples and used a basic home soil test to get an idea of what I’m dealing with. pH ranges 7.0-7.6 (Avg. 7.3). Nitrogen effectively depleted. Phosphorous adequate to high adequate and K low adequate to adequate. I plan to add some EWC and some additional amendments (high N, Ca, elemental sulfur + Sul/Po/Mg, azomite). I will hit the roots with mycorrhiza when I plant in. Appreciate any thoughts on that plan or if anyone has an alternate or additional suggestions.
 

St. Phatty

Active member
Granite is radioactive, I wouldn't be eating or smoking anything grown in it.

OH GOOD !!!

I've been wanting to play with Uranium.

I was going to say, de-composed Granite is OK for mature plants but don't bring it around seedlings.

Might as well put wet concrete on top of them.
 

Ur Humbl Nr8tor

Well-known member
Veteran
Granite is radioactive, I wouldn't be eating or smoking anything grown in it.

Haha. I think most articles discussing radiation concerns have to do with granite harvested and used in things like countertops...not DG from soil samples. In reality, all naturally formed soil and rocks likely contain radioactive isotopes (radon)...so any soil mix containing rock or rock dust could have extremely small amounts of these isotopes. We’ve been harvesting citrus, avocados, nuts, etc. from this grove for many years. This soil type produces a significant amount of produce consumed in N. America. Sandy, granite loam with minimal clay deposits.
 

Ur Humbl Nr8tor

Well-known member
Veteran
OH GOOD !!!

I've been wanting to play with Uranium.

I was going to say, de-composed Granite is OK for mature plants but don't bring it around seedlings.

Might as well put wet concrete on top of them.

Plan to transplant in established plants from seed or clone. Not directly sow seeds. Thanks for the input.
 

slownickel

Active member
ICMag Donor
Veteran
Are you located in S. Cal? I have a lot of soil analysis from the Temecula area. Manage a lot of avocado there.
 

Ur Humbl Nr8tor

Well-known member
Veteran
Are you located in S. Cal? I have a lot of soil analysis from the Temecula area. Manage a lot of avocado there.

This grove is nearby Rock Mountain. I’d love to have whatever info you can provide. Feel free to provide any info here, or PM me. Thanks!
 

Chunkypigs

passing the gas
Veteran
slownickel- Before you hip this dude to the pleasures of gypsum.... what do you recommend for lightening up a local soil like this? I know in Cali you guys have access to volcanic rock but pretend it was the east coast and none available?
 

slownickel

Active member
ICMag Donor
Veteran
slownickel- Before you hip this dude to the pleasures of gypsum.... what do you recommend for lightening up a local soil like this? I know in Cali you guys have access to volcanic rock but pretend it was the east coast and none available?

Missing some details there, indoors? outdoors? what crop? If it is weed, you need to see what is available locally. Rice hulls is a great one. Half decomposed wood chips, chunky coco, pithy peat and of course the right calcium source to flocculate the soil chemically. Drainage is also important, so beds are always recommended.
 

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