Gypsum & Clay

[ExperimentalGrower]

I have dense Adobe clay in my yard, and have been researching using applications of gypsum to break it up. Has anyone tried this? Is there a particular trick to applying it? 
 

I’m still not sure after all the reading I’ve done what the mechanism of action is that allows gypsum to break up clay and to what depth it will be effective. Any insight is appreciated!

[akamu]

I planted a 15gal dypsis lutescens outside my kitchen window to create a screen . There was a 50 yr old olive tree there before and the clay hole after removing the Olive Tree held water for 2-3 days  It was like a cement pot.  I added a ton of gypsum and drilled about 8 holes in the bottom  of the pit and filled those also . It now drains super fast and the palm has grown exceptionally well The bagged gypsum also contains 15% sulfur which is good for fighting fungal infections The addition of organic matter also improves the loosening effect and works well with gypsum applications. 

[ExperimentalGrower]

7 hours ago, akamu said:

I planted a 15gal dypsis lutescens outside my kitchen window to create a screen . There was a 50 yr old olive tree there before and the clay hole after removing the Olive Tree held water for 2-3 days  It was like a cement pot.  I added a ton of gypsum and drilled about 8 holes in the bottom  of the pit and filled those also . It now drains super fast and the palm has grown exceptionally well The bagged gypsum also contains 15% sulfur which is good for fighting fungal infections The addition of organic matter also improves the loosening effect and works well with gypsum applications. 

Awesome, very helpful. Thanks!

[Dartolution]

Gypsums use with heavy clay, sandy, and salt laden soils cannot be underestimated! 

I can personally attest to this. I live in the south, and have very deep red, heavy, native clay soil. After 3 years of consistent applications (btw I've found this to be key, I apply it quarterly at the beginning of each season), and heavily amending the area with lots of organic matter and organic fertilizers it has turned the soil on my little property from yuck and muck to straight up earthworm heaven, black gold, miracle dirt. 

 

The key with clay is to amend and inject as much organic matter as you can. 

I use soil conditioner (pine fines), mulches, used coffee grounds (consistently), orange peels, good potting mix (jungle growth), and espoma organic fertilizers. 

I also water all the plants (palms included) with a mixture of seaweed extract and unsulfered blackstrap molasses on a 2 week schedule during the growing season with a hose end sprayer set to 3oz gallon. The constant supply of carbohydrates[sugars], minerals, and the trace elements and growth hormones found in the seaweed have been feeding the micro and macrofauna of the soil.

As earthworm populations rise, they produce more castings as a result. etc etc...

All of this combined has been a wonderful recipe for success for me. 

 

 

[sonoranfans]

First clay can either be made of high Na or high Ca content.  Gypsum is CaS04 and can be very useful for high sodium soils.  Gypsum is made of ions Ca2+ and S04 2- , the latter prefers to bond with Na in soil thus breaking up soils locked with sodium.  However if you have high calcium soils that are locked up by calcium adding gypsum does nothing except increase Ca, which doesnt break up the soil which has too much Ca already that is why its not draining.  This can be unhealthy for your palms which prefer a Mg/CA ratio of about 1:3 for best nutrient uptake.  Too much Ca can cause uptake issues with Mg and with K, not good.  SO the answer is yes it can help but that depends on your soil composition.  If you have high calcium or limestone soils. CA is already high and it does nothing.  To deal with high calcium soils where calcium is the culprit locking up your soil drainage, adding sulfur pellets will work over time.  S+02+bacteria+tyime-> S02, S02+H20-> H2S03-,  which is sulfurous acid.  Then HS03- + H20 + Ca-> CaS04 + H2 + H+ and you have created gypsum in situ by taking away the Ca that is locking up your soil.  It also lowers soil pH.  This is soil chemistry and if your calcium is initially high, gypsum could just make things worse. 

[Keys6505]

3 hours ago, sonoranfans said:

First clay can either be made of high Na or high Ca content.  Gypsum is CaS04 and can be very useful for high sodium soils.  Gypsum is made of ions Ca2+ and S04 2- , the latter prefers to bond with Na in soil thus breaking up soils locked with sodium.  However if you have high calcium soils that are locked up by calcium adding gypsum does nothing except increase Ca, which doesnt break up the soil which has too much Ca already that is why its not draining.  This can be unhealthy for your palms which prefer a Mg/CA ratio of about 1:3 for best nutrient uptake.  Too much Ca can cause uptake issues with Mg and with K, not good.  SO the answer is yes it can help but that depends on your soil composition.  If you have high calcium or limestone soils. CA is already high and it does nothing.  To deal with high calcium soils where calcium is the culprit locking up your soil drainage, adding sulfur pellets will work over time.  S+02+bacteria+tyime-> S02, S02+H20-> H2S03-,  which is sulfurous acid.  Then HS03- + H20 + Ca-> CaS04 + H2 + H+ and you have created gypsum in situ by taking away the Ca that is locking up your soil.  It also lowers soil pH.  This is soil chemistry and if your calcium is initially high, gypsum could just make things worse. 

Are there any visual qeues that would tip off if the clay is high in Na or CA?  Or would I just have to get the dirt tested?

[sonoranfans]

I can think of no visual cues for determining soil cation content.  Sulfur should work on both high sodium and high calcium soils, if your soil is alkaline the sulfur also will bring alkalinity down .  I have also used SDS surfactant and humic acid to help break down heavy clay soil and remove heavy metals.  https://www.sciencedirect.com/science/article/abs/pii/S0011916407002299

 

[rprimbs]

I'm in Escondido, San Diego.  And I've got a Bachelor's degree in Geology.  And I confess I never understood why gypsum would help, so thank you Sonorafans.  I only worked a little as a geologist (On the infamous PG&E Hinkley remediation, and for an Environmental Consulting firm for a little over a year).  Then I became a truck driven, an electrician,  and now I'm back as a truck driver.

 

Here in Escondido, we have granite.  But it is not the quartz rich, gold bearing, type of granite.  We have veins of 'orthoclase'.  Orthoclase is KAlSi3O8.  The glittery stuff in our granite is not gold.  It's biotite, K(Mg,Fe) 3(AlSi 3O 10)(F,OH) 2.    That contains no calcium either.  So maybe gypsum would not work so well here.

We have 'clay' here, but not really fine clay.  'Clay' just refers to the grain size -- very small grain size.  You know you take a big boulder and you break the thing in half, and you now have new surfaces for water to stick to.  You break those in half and you have more surfaces for water to stick to.  The smaller the grain size the greater the surface area.  This is why 'clay' 'holds' so much water.  And some minerals will break down smaller than others.  Quartz only breaks down into sand.

 

[ExperimentalGrower]

5 hours ago, Dartolution said:

Gypsums use with heavy clay, sandy, and salt laden soils cannot be underestimated! 

I can personally attest to this. I live in the south, and have very deep red, heavy, native clay soil. After 3 years of consistent applications (btw I've found this to be key, I apply it quarterly at the beginning of each season), and heavily amending the area with lots of organic matter and organic fertilizers it has turned the soil on my little property from yuck and muck to straight up earthworm heaven, black gold, miracle dirt. 

 

The key with clay is to amend and inject as much organic matter as you can. 

I use soil conditioner (pine fines), mulches, used coffee grounds (consistently), orange peels, good potting mix (jungle growth), and espoma organic fertilizers. 

I also water all the plants (palms included) with a mixture of seaweed extract and unsulfered blackstrap molasses on a 2 week schedule during the growing season with a hose end sprayer set to 3oz gallon. The constant supply of carbohydrates[sugars], minerals, and the trace elements and growth hormones found in the seaweed have been feeding the micro and macrofauna of the soil.

As earthworm populations rise, they produce more castings as a result. etc etc...

All of this combined has been a wonderful recipe for success for me. 

 

 

This is awesome, thanks man. You’re following similar principles I’m using, making sure to foster the soil food web. I’ve been reading the book in the pic learning how to harness this method. So far it seems to be working. I’m doing a lot of amending with various organics, and using a lot of mycorrhizal applications when planting.
 

One question regarding gypsum- are you top dressing with it and letting it leach into the soil? Just trying to figure out how to effectively apply it in established beds. 

[ExperimentalGrower]

4 hours ago, sonoranfans said:

First clay can either be made of high Na or high Ca content.  Gypsum is CaS04 and can be very useful for high sodium soils.  Gypsum is made of ions Ca2+ and S04 2- , the latter prefers to bond with Na in soil thus breaking up soils locked with sodium.  However if you have high calcium soils that are locked up by calcium adding gypsum does nothing except increase Ca, which doesnt break up the soil which has too much Ca already that is why its not draining.  This can be unhealthy for your palms which prefer a Mg/CA ratio of about 1:3 for best nutrient uptake.  Too much Ca can cause uptake issues with Mg and with K, not good.  SO the answer is yes it can help but that depends on your soil composition.  If you have high calcium or limestone soils. CA is already high and it does nothing.  To deal with high calcium soils where calcium is the culprit locking up your soil drainage, adding sulfur pellets will work over time.  S+02+bacteria+tyime-> S02, S02+H20-> H2S03-,  which is sulfurous acid.  Then HS03- + H20 + Ca-> CaS04 + H2 + H+ and you have created gypsum in situ by taking away the Ca that is locking up your soil.  It also lowers soil pH.  This is soil chemistry and if your calcium is initially high, gypsum could just make things worse. 

Fascinating stuff even though I don’t really understand the chemistry. Thanks man. So in your opinion I should get a soil test done to determine what I’m dealing with first before dumping a load of gypsum into my garden. 
 

If after a soil test it’s determined gypsum could be a benefit how do you recommend it be applied? Top dress? Deep amendment? 

[rprimbs]

1 hour ago, rprimbs said:

I'm in Escondido, San Diego.  And I've got a Bachelor's degree in Geology.  And I confess I never understood why gypsum would help, so thank you Sonorafans.  I only worked a little as a geologist (On the infamous PG&E Hinkley remediation, and for an Environmental Consulting firm for a little over a year).  Then I became a truck driven, an electrician,  and now I'm back as a truck driver.

 

Here in Escondido, we have granite.  But it is not the quartz rich, gold bearing, type of granite.  We have veins of 'orthoclase'.  Orthoclase is KAlSi3O8.  The glittery stuff in our granite is not gold.  It's biotite, K(Mg,Fe) 3(AlSi 3O 10)(F,OH) 2.    That contains no calcium either.  So maybe gypsum would not work so well here.

We have 'clay' here, but not really fine clay.  'Clay' just refers to the grain size -- very small grain size.  You know you take a big boulder and you break the thing in half, and you now have new surfaces for water to stick to.  You break those in half and you have more surfaces for water to stick to.  The smaller the grain size the greater the surface area.  This is why 'clay' 'holds' so much water.  And some minerals will break down smaller than others.  Quartz only breaks down into sand.

 

Wait I had that backwards!  The gypsum probably would work well here because our soIls aren't high in calcium.  Sorry I was sort of multitasking when I wrote that.

[ExperimentalGrower]

7 minutes ago, rprimbs said:

Wait I had that backwards!  The gypsum probably would work well here because our soIls aren't high in calcium.  Sorry I was sort of multitasking when I wrote that.

Curious where our NorCal adobe clay soils lay in the equation...

[Dartolution]

3 hours ago, ExperimentalGrower said:

This is awesome, thanks man. You’re following similar principles I’m using, making sure to foster the soil food web. I’ve been reading the book in the pic learning how to harness this method. So far it seems to be working. I’m doing a lot of amending with various organics, and using a lot of mycorrhizal applications when planting.
 

One question regarding gypsum- are you top dressing with it and letting it leach into the soil? Just trying to figure out how to effectively apply it in established beds. 

@ExperimentalGrower great book!

When I prepare an area for planting I mix in gypsum to the bed/area. However, when I add it quarterly, I just broadcast it over the area and allow it to wash in as I water/rain happens. 

[rprimbs]

2 hours ago, Dartolution said:

@ExperimentalGrower great book!

When I prepare an area for planting I mix in gypsum to the bed/area. However, when I add it quarterly, I just broadcast it over the area and allow it to wash in as I water/rain happens. 

At the risk of being wrong I will venture a guess.  I went to California State University, Sacramento.  Northern California is 'gold country'.  You have quartz veins and granite rich in quartz.  

My parents had 'expansive clay' at their place in Davis.  The minerals in the rock broke into very fine grains.  I think the gypsum would work. 

In parts of the midwest, and the south, where there is a lot of limestone (CaCO3, calcium carbonate) gypsum would not work.

Hopefully I have this right

 

 

[ExperimentalGrower]

4 hours ago, rprimbs said:

At the risk of being wrong I will venture a guess.  I went to California State University, Sacramento.  Northern California is 'gold country'.  You have quartz veins and granite rich in quartz.  

My parents had 'expansive clay' at their place in Davis.  The minerals in the rock broke into very fine grains.  I think the gypsum would work. 

In parts of the midwest, and the south, where there is a lot of limestone (CaCO3, calcium carbonate) gypsum would not work.

Hopefully I have this right

 

 

Thanks for the input. I imagine I have clay almost the same as in Davis; Vallejo isn’t too far. 

[ExperimentalGrower]

7 hours ago, Dartolution said:

@ExperimentalGrower great book!

When I prepare an area for planting I mix in gypsum to the bed/area. However, when I add it quarterly, I just broadcast it over the area and allow it to wash in as I water/rain happens. 

Really interesting that top dressing gypsum still works via the leaching process.

[Dartolution]

14 hours ago, rprimbs said:

At the risk of being wrong I will venture a guess.  I went to California State University, Sacramento.  Northern California is 'gold country'.  You have quartz veins and granite rich in quartz.  

My parents had 'expansive clay' at their place in Davis.  The minerals in the rock broke into very fine grains.  I think the gypsum would work. 

In parts of the midwest, and the south, where there is a lot of limestone (CaCO3, calcium carbonate) gypsum would not work.

Hopefully I have this right

 

 

We do have limestone deposits, and mines around here, however gypsum still seems to work in my immediate area. Perhaps its more of the interaction between the addition of organic matter, and fostering a robust soil ecology in my specific area than that of just the simple addition of gypsum. Whatever it is, it seems to work for me. 

@ExperimentalGrower I don't see why it wouldn't work with leaching unless you're on a severe incline or have heavy rain/weather that washes/displaces it.

I would think as it is worked into the soil, and beneficial micro/macrofauna conduct their activities, it would slowly be worked in deeper and deeper. 

This is all speculation of course. 

 

[sonoranfans]

My microbe maintnance solution is top mulch and humic acid.  Humic acid(s) is(are) the natural final product of compost and the mulch mostly works its way into the soil at the end of each summer.  The mulching and humic acid additions support mycorrhizal bacteria and also the good/bad nematode balance which is critical in sandy soils.  Humic supresses those bad root eating nematodes and further is a chelating agent for heavy metals(holds them) and nutrients(reeases them), both of which also can help microbes.  Nematodes are very common here in my area of florida, and they can really stunt your palms by feeding on the roots.  I have ben mulching and putting a wet(polydisperse) humic acid solution down for 10 years annually.  When it rains you can see how the soil is loaded with earthworms now.  

 

[Dartolution]

I want to say that either the Dr. Earth or Espoma, or both, products contain something like 4-5% Humic acids. 

I incorporated adding liquid humic/fulvic acid into my 2 week fertilizer regime last year. 

[sonoranfans]

here is is link on use of gypsum.  Its from a mster gardeners perspective, not so heavy in chemistry.  But thy allude that adding gypsum may cause high Ca in some soils.  Gypsum is good for removing salt from your soil(Na included) as ti reacts and binds with Na.  For a sandy soil, you probably should not use gypsum.  https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/using-gypsum-in-garden.htm

a quote from conclusions:

 " Studies have shown that soils with at least 10 percent organic matter don’t benefit from the addition of gypsum. It also has no effect on soil fertility, permanent structure or pH, while generous amounts of compost will do all that and more. In short, you can benefit new landscapes by application of gypsum on compacted soil if you have a need for calcium and have salt laden earth. But for the majority of gardeners, the mineral is not necessary and should be left for industrial agricultural use."   I will add that IMO, for calcium deficient compacted soils it is the best treatment possible.  I have sandy soils so I dont use gysum.
 

[ahosey01]

On 3/31/2021 at 8:53 AM, sonoranfans said:

First clay can either be made of high Na or high Ca content.  Gypsum is CaS04 and can be very useful for high sodium soils.  Gypsum is made of ions Ca2+ and S04 2- , the latter prefers to bond with Na in soil thus breaking up soils locked with sodium.  However if you have high calcium soils that are locked up by calcium adding gypsum does nothing except increase Ca, which doesnt break up the soil which has too much Ca already that is why its not draining.  This can be unhealthy for your palms which prefer a Mg/CA ratio of about 1:3 for best nutrient uptake.  Too much Ca can cause uptake issues with Mg and with K, not good.  SO the answer is yes it can help but that depends on your soil composition.  If you have high calcium or limestone soils. CA is already high and it does nothing.  To deal with high calcium soils where calcium is the culprit locking up your soil drainage, adding sulfur pellets will work over time.  S+02+bacteria+tyime-> S02, S02+H20-> H2S03-,  which is sulfurous acid.  Then HS03- + H20 + Ca-> CaS04 + H2 + H+ and you have created gypsum in situ by taking away the Ca that is locking up your soil.  It also lowers soil pH.  This is soil chemistry and if your calcium is initially high, gypsum could just make things worse. 

How do you know if the soil is high in Sodium vs. Calcium?  Is there a trick other than getting your soil tested for its chemical composition?

Edited April 1, 2021 by ahosey01

[rprimbs]

On 4/1/2021 at 4:06 PM, ahosey01 said:

How do you know if the soil is high in Sodium vs. Calcium?  Is there a trick other than getting your soil tested for its chemical composition?

I'm not much of a geologist, but to some extent you can guess at the type of minerals that make up a soil by the color.

Here in inland San Diego the orange, or even 'pinkish' color of the veins of rock, as well as the cleavage faces, make it easy to identify as 'potasium feldspar' -- orthoclase.  In other areas you might have a sodium feldspar, or a calcium feldspar.  Or something in between the two..

Here I will try to post a picture.

[rprimbs]

Maybe one more thing I should add is that iron can also give you a reddish color.  So if you live in the desert and you have good red colored gold bearing rock, then it is probably because of iron.