Gypsum VS. Lime In Compacted Clay

Some people who are William Albrecht followers promote magnesium for "tightening up" sandy soil and Lime for "Loosening up" clay. I haven't heard them recommend gypsum though, which seems strange since it doesn't change PH as much and just raises calcium - exactly what they are usually trying to do.

Anyway, If someone has compacted clay that needs the structural "loosening", i.e. better drainage, is gypsum a better choice over lime assuming that they both do in fact loosen the clay? Or would the PH raising effect of the lime not matter? Would the slightly higher cost of gypsum be a waste of money?

Here are a couple of typical Albrecht inspired articles (anyone with better articles be sure to post them!) but there is no mention of gypsum in them:

http://www.qfirst.net/pdf/Ch%203%20Balanced%20Soil%20Cations.pdf


http://www.soilminerals.com/Cation_Exchange_Simplified.htm

Most of the research I have done says the same you are proposing--use lime if you need to raise pH and gypsum if you don't, but most just use the cheapest available-if you are doing more than a garden bed the price starts to matter.

Yes, if the choice is theoretically "Compacted clay swamp" vs. "Usable soil that is really alkaline from the cheap lime I used" I suppose the second option is much, much, much, much better?

I use the third option myself: scrap drywall. The builders of new homes throw huge amounts of drywall into dumpsters to be carted off to the landfill. Probably more than a ton for each average size house. You aren't going to find gypsum for less and all it takes is a little patience for the paper to decay away after it gets rained on a few times.

Gypsum is calcium+sulphur, whereas lime is just calcium and no sulphur.
That is the reason why Gypsum does not raise the ph as much because it is balanced out by the acidic sulphur

.. it's hard to tell what you are even getting when purchasing ammendments.. 'pelletized gypsum' is simply municipal sewage sludge- add some to water and see.. the feds allow these sorts of waste to be disposed of in solid field fertilizers.. I would heartily recommend Dr. Albrecht's guidelines in approaching 'lime' and 'Ph'.. address the calcium levels, and let the rest follow on its own.. also 'indicator plants' make a great substitute for soil tests- handier, less costly and confusing, and site/season/climate specific.. best of luck!

S Bengi wrote:Gypsum is calcium+sulphur, whereas lime is just calcium and no sulphur.
That is the reason why Gypsum does not raise the ph as much because it is balanced out by the acidic sulphur

In my parts "lime" means calcium + magnesium. I chose to go down the John Elliot path of drywall, CaSo4 + all the wonderful impurities. Gypsum is not a liming agent, but can be used like one.

I skipped out on the magnesium specifically because I don't want any "tightening" of the soil, at least for now, since the soil is pretty damn tight.

I will probably use the calcium-magnesium lime as an amendment to chicken-produced-compost in the early stages, the same with some type of phosphorus (soft rock phosphate if I can get it). I want that stuff integrated into a life-rich substance.

I get drywall powder by the truckload for 20 euros at a recycling center. I'm planning to ask the people at the dump to hold out any drywall for me to make the drywall chips.

William

You want to keep your magnesium+sulphur ratio in balance. You will have to get a soil test.
Calcium should be 70% of your CEC base saturation and Magnesium 10%. combine they should be 80%.
Alot of people say that 65% Ca and 15%Mg gives the best result. You dont want your soil to have over 20% Mg base saturation of CEC (20%Mg and 60% CA).

Over 70% Calcium base saturation CEC and the other nutrients become exponentially less available to plants esp the micro-nutrients.

If possible add biochar to the soil to losses it up. You can add up to 8ton per acre but no more.
Dont add too much magnesium it make the soil behave more sticky and less loose, which is not what we want.

I use 50% Ca and 30% Mg or so, and agricultural testing has shown that this ratio is perfectly acceptable.

There are much more important questions here, like:
-do you actually need additional calcium in your soil?
-do you actually need additional sulfur in your soil?
-do you actually need additional magnesium in your soil?
-what is your current soil pH and CEC?

The rule is simple: Don't add things you don't need. Add things you do need. Common sense.

That said, I haven't noticed any difference in compaction due to applying dolomite. I have noticed a big difference in compaction where the worms had a party under my hugelkultur. If you add some rock dust and greensand and then pile up sheet mulch on top, you can lighten your clay into a clay loam, which is much better for growing things. If your climate and soil promote rapid breakdown of organic matter, biochar can help tremendously as well.

Your soil type Utisols naturally have a combined (Ca+Mg)based saturation below 35% vs the "optimal" 80%.
So any changes will most likely be an acceptable improvement for your crops.

In terms of loosing up your soil, adding biomass is the best way to go. However most clay soil also need mineralization and could possible benefit from a higher ph, but like everything in life it depends.

Marc Troyka wrote:I use 50% Ca and 30% Mg or so, and agricultural testing has shown that this ratio is perfectly acceptable.

There are much more important questions here, like:
-do you actually need additional calcium in your soil?
-do you actually need additional sulfur in your soil?
-do you actually need additional magnesium in your soil?
-what is your current soil pH and CEC?

The rule is simple: Don't add things you don't need. Add things you do need. Common sense.

That said, I haven't noticed any difference in compaction due to applying dolomite. I have noticed a big difference in compaction where the worms had a party under my hugelkultur. If you add some rock dust and greensand and then pile up sheet mulch on top, you can lighten your clay into a clay loam, which is much better for growing things. If your climate and soil promote rapid breakdown of organic matter, biochar can help tremendously as well.

Thomas A. Cahan wrote: 'pelletized gypsum' is simply municipal sewage sludge

Can I get a source for this claim? (other than add some water and see for myself)

S Bengi wrote:

Over 70% Calcium base saturation CEC and the other nutrients become exponentially less available to plants esp the micro-nutrients.

According to Steve Soloman and others it is nearly impossible to add too much calcium. Any excess just gets washed down into the subsoil where it can do it's magic there.

Quoting Soloman: "considering my own positive experiences...and the writings of Victor Tiedjens, it seems impossible to create a damaging calcium excess with agricultural lime. No matter how much ag lime is spread, calcium saturation will not exceed 85%, at that saturation, food crops still grow excellently because there remains another 15% on the exchange sites to provide plants with more than enough of the other cations"
William

S Bengi wrote:
In terms of loosing up your soil, adding biomass is the best way to go. However most clay soil also need mineralization and could possible benefit from a higher ph, but like everything in life it depends.

I have noticed that it takes mountains of biomass to feed these kinds of soil. The biomass just doesn't stick around. Biochar is an alternative I haven't tried, but it addresses this problem. The other thing to note is that while most gardening books discourage the incorporation of biomass with soil, in these soils it's better to incorporate and put some on top. Any biomass that you put on top of the soil (unless it's woody) evaporates and you are left with exactly the same soil you started with. I haven't tried incorporating large amounts of woodchips, but that could also be something to try. Staking the clay soil with decomposing branches is also something I'm experimenting with.

With the biochar, I'm worried that it might promote bacteria at the expense of fungi. Especially because I'm looking toward having trees in the future, I want there to be a good portion of fungi. But if you're just doing annual crops, going for biochar might be sensible.

Nutrient balancing helps to create the tilth and structure conducive to life. A little biomass is good and helpful, but I believe balancing the nutrients might be a better path toward creating the soil you want.
William

Suggested Gypsum limit is one ton per acre, just so you know. I think I went over that by a lot, since I'm doing 400 square meters. The plants are looking quite healthy at the moment, my disappointing soil test notwithstanding.
William

@Johnny niamert,

The official story is that for pelletized lime it's just coated in lignosulphonate, haven't heard about gypsum but I imagine it's the same. My pelletized lime DOES look like poop though haha - maybe Thomas is right.

http://www.uky.edu/Ag/Agronomy/Extension/ssnv/ssvl189.htm

Bryan Jasons wrote:@Johnny niamert,

It's an egregious claim. Especially so without any evidence.

I use waste drywall to add Ca and S too. I generally only use it when I have done drywall work at home and have some scrap drywall that I don't want to put in a landfill.

I didn't know about Calcium saturation dilluting into lower soil but that's good to know.

William James wrote:

S Bengi wrote:

Over 70% Calcium base saturation CEC and the other nutrients become exponentially less available to plants esp the micro-nutrients.

According to Steve Soloman and others it is nearly impossible to add too much calcium. Any excess just gets washed down into the subsoil where it can do it's magic there.

Quoting Soloman: "considering my own positive experiences...and the writings of Victor Tiedjens, it seems impossible to create a damaging calcium excess with agricultural lime. No matter how much ag lime is spread, calcium saturation will not exceed 85%, at that saturation, food crops still grow excellently because there remains another 15% on the exchange sites to provide plants with more than enough of the other cations"
William

I have not read Solomon, so bear with me, please Exactly what is it that he is describing where calcium saturation will not exceed 85%?

@S Bengi
Its kind of a complicated concept spread out over 3 or 4 parts of Soloman's book, and I don't really understand it.

One aspect is that by adding lots of calcium you are creating a synthetic calcareous soil. The other key is that Albrect's TCEC no longer applies when you're doing this, and soil tests will give inaccurate results of pH and TCEC. I think he suggests a weak-acid M3 test.

He cite two books that discusses this concept, available on soilanalyst.org:
-More Food from Soil Science: The natural chemistry of lime in agriculture 1965
-Olena Farm, USA An Agricultural Success Story 1969

Hope that helps.
William

Gypsum Flower I made in a plastic cup, ultra high strength gypsum, beta gypsum UJ Type, beta gypsum PX Type, different whiteness.

Thomas A. Cahan wrote:.. it's hard to tell what you are even getting when purchasing ammendments.. 'pelletized gypsum' is simply municipal sewage sludge- add some to water and see.. the feds allow these sorts of waste to be disposed of in solid field fertilizers.. I would heartily recommend Dr. Albrecht's guidelines in approaching 'lime' and 'Ph'.. address the calcium levels, and let the rest follow on its own.. also 'indicator plants' make a great substitute for soil tests- handier, less costly and confusing, and site/season/climate specific.. best of luck!

He is right. Near me there are two forms of bulk fertilizer free for the taking for large farmers; municipal sludge which is the 1% that cannot be broken down in sewer treatment plants, and a lime slurry used in many of the paper mills here.

Of the two, the latter was really the best as it was a lime substitute for our acidic soil. However municipal sewer sludge was not wanted at all and yet that was in abundance and what every city wanted to get rid of. So someone came up with the idea that if farmers wanted to get rid of something few farmers wanted, just mix it in with what what we did, and it worked. Now in order for us to get the lime substitute we so desperately need, we have to either buy lime out of New Brunswick Canada (6 hours away and imported), use heavy concentrations of a seaweed byproduct, or agree to municipal sludge mixed with lime slurry. Personally I refuse the latter because doing so renders farmland uninhabitable for domestic residences (houses) for 100 years. Yeah, its that bad.

The municipal sludge is everywhere too. When they pave a street or sidewalk and they have to use loam to fill in behind curbs or whatnot, it is a mixture of sludge and loam too.

I have heartburn about this because near me there is a plant that does process municipal sludge. They compost it which is the right thing to do. I mean 99% of what cities produce is being processed so that is a very good thing compared to letting it flow into our rivers, but there is a way for it to be processed appropriately. Instead they simply want to hoodwink the public and dump it all around right under our noses by using different names; Lime substitute, loam, etc.

Sorry I cannot give you a link, but I know first hand what Thomas says is true on a large farming scale. It would not surprise me that it is also in bagged versions of commercial fertilizer. Why wouldn't it be; get the NPK people are after for free? Considering more land is used for lawns then crops in this country, and more fertilizer overuse is done upon lawns...it only makes sense bagged fertilizer products are exploited.