pH stuff

This thread is about my article here:  http://richsoil.com/ph

Oh yeah - it started about lawn stuff, but it has stuff about veggies and soil in general ...

Good article.  Good idea, to bump it back into circulation.

You might mention that charcoal has all the minerals that would be in its ashes, and has a vaguely similar effect on pH.

I've also read that acid-loving plants can grow on soil that's mostly limestone gravel, if the rain is frequent enough to acidify the surface layer and to keep the plant alive with such shallow roots.

My obligator zany idea: Is there any merit to spreading decomposed granite or crushed concrete on a lawn? Or would it shade the lawn if applied thickly enough to amend pH?

Joel Hollingsworth wrote:
Is there any merit to spreading decomposed granite or crushed concrete on a lawn? Or would it shade the lawn if applied thickly enough to amend pH?

Somehow that makes me think that there would then be rocks on the surface - not very conducive to walking on a lawn barefoot.

Assuming that they both come in a powder, then I have to say:  I don't know.  I don't know what their pH is, and I don't know if there might be other stuff in there that would give me the willies.

There's thorium in granite. Enough to detect, but not enough to be a certifiable danger. Certainly not as much as you'd find in lantern mantles. But it does give a lot of people the willies...seriously, though, if you're looking to have the willies, you can always find something. For example, there's also some thorium in limestone, but usually more uranium.

Granite has been used as a source of K and of "trace minerals" in general for soil mixes. Being high in silica, it's a sink for lime, and so granite-based soils tend to be acidic.

Concrete is made using lime. It tends to be noticeably basic. There are so many options in formulating it that you'd have to decide on a case-by-case basis, but structures that are being demolished now are unlikely to have been built with fly ash, and trace mineral content will probably vary more based on what aggregate was used.

Both are definitely available as powder, or with a texture like coarse sand or very fine gravel. Crushed concrete is sometimes available for free through Craigslist, in a variety of sizes.

Joel Hollingsworth wrote:
There's thorium in granite. Enough to detect, but not enough to be a certifiable danger. Certainly not as much as you'd find in lantern mantles. But it does give a lot of people the willies...seriously, though, if you're looking to have the willies, you can always find something. For example, there's also some thorium in limestone, but usually more uranium.

Granite has been used as a source of K and of "trace minerals" in general for soil mixes. Being high in silica, it's a sink for lime, and so granite-based soils tend to be acidic.

Concrete is made using lime. It tends to be noticeably basic. There are so many options in formulating it that you'd have to decide on a case-by-case basis, but structures that are being demolished now are unlikely to have been built with fly ash, and trace mineral content will probably vary more based on what aggregate was used.

Both are definitely available as powder, or with a texture like coarse sand or very fine gravel. Crushed concrete is sometimes available for free through Craigslist, in a variety of sizes.

Hello Joel:

A gardener would go a long time without hearing this information you've posted. I have a 6 acre market farm and have added, with compost and manure (40m+c-50rockpowder) to hundreds of tons of 4 types of rock dusts I have had hauled by the tandem load to my farm. I have used  this material to enrich soil for the benefit of plants, microorganisms and invertebrates and to permanently
prevent any compaction of my soil that would significantly reduce the productivity of the gardens. The materials include "siltation pond fines" from the following types of rock: granite, volcanic tuff (maybe basalt, very hard rock, 2nd hardest in NC) and pyrophyllite screenings. I am glad to hear that granite, high in silica is a sink for lime making my soil acidic, good for most crops, pH 6.1 to 6.6 or so (just guessing). I hav copies of the MSDS sheets on the tuff/basalt and the pyrophyllite. Thanks very much for your excellent information. Here's some reading for you to enjoy:
http://www.ibiblio.org/ecolandtech/documents/gardening-hand-tools.faq
Lots of info on hand garden tools and sources for them and my thoughts on double dug gardens plus lots of soil quality info & remineralization.
And my blog:
Venaura Farm Permaculture
http://venaurafarm.blogspot.com

Cheers,

LFLondon
lflj@belsouth.net
venaurafarm@bellsouth.net

I'm all about the ivory tower science.

Good to hear from someone who's used the stuff!

I know in ancient South America, potsherds were used as a soil amendment, and I think one of the major purposes was to prevent compaction.

If you don't mind me asking, how do fines work to prevent compaction?  I'm used to "fines" being particles tens of nanometers across, but an aggregates person might use the term a lot differently than a ceramist like myself. A good pozzolan might bind to soil and create a good crumb structure, but I wouldn't expect that to be foolproof or permanent, so I'm guessing there are some visible particles in the material you're using.

Joel Hollingsworth wrote:
I'm all about the ivory tower science.

Good to hear from someone who's used the stuff!

I know in ancient South America, potsherds were used as a soil amendment, and I think one of the major purposes was to prevent compaction.

If you don't mind me asking, how do fines work to prevent compaction?  I'm used to "fines" being particles tens of nanometers across, but an aggregates person might use the term a lot differently than a ceramist like myself. A good pozzolan might bind to soil and create a good crumb structure, but I wouldn't expect that to be foolproof or permanent, so I'm guessing there are some visible particles in the material you're using.

This, from my gardentools faq:
"You want highly mineralized soil, high in tilth and fertility, producing vegetables and fruits with exceptional flavor.
Add rock dust from quarries to your garden soil for trace minerals, microbe food and tilth, permanently eliminating soil
compaction. This is called siltation pond fines. It is so fine that if you put some in a glass of water it turns cloudy
and stays that way for quite a while before settling into a layer of sludge on the bottom; so fine it would take a microscope
to see the individual particles. This is great material to feed plants and soil microorganisms and invertebrates in your garden."

I think we are talking 200 mesh or finer; some fines are a little coarse by comparison to my basalt/tuff fines and some are an
aggregate with the largest component almost microscopic, like the talcum powder in pyrophylite fines (dredged from the quarry's siltation ponds).  To prevent compaction, permanently, fines act mechanically to interfere with clay and silt particles that when compressed when wet become highly compacted when dried out - a serious problem for gardeners needing productive high-tilth soil.
Tillage is expensive, disruptive of soil life and inconvenient when it needs to be done and the soil is too wet; i.e. weeds can get out of control and go to seed when tillage can't be done, like in Spring, to remove them and create a fine, weed free seedbed for new plantings. Fines are mixed with existing soil on site, sometimes in a 30 or 40 to 50 ratio. The clay or silt particles become permanently separated from each other and cannot be seriously compacted again. This effect is also achieved with the addition of compost or manures to the soil. The fines feed the microorganisms that help break down the fines and make trace minerals available to plants; these microbes also break down any raw or composted organic matter added to soil to become humus, feed released nutrients to crops and improve the soil crumb structure providing added tilth to your garden soil. The extra trace minerals in garden soil makes crops taste much better. The famous tomatoes grown in volcanic soils in places in Italy taste so good for this same reason. That's how fines reelieve compaction and add to soil health and vitality, crop health and disease and predator resistance and crop flavor, appearance and keeping qualities. More about fines dissolved in water. In places in the high country areas in Eastern countries people drink cold river water that is cloudy and high in mineral content; they live long lives.

LFLondon

Ah, that all makes sense now. Thanks!

I understand that Roman aqueducts were built by finding people with healthy teeth and bones, stealing their water, and piping that to the nearest city. Huge amounts of minerals built up in these water systems as a result, but presumably this strategy helped the empire mitigate the effects of consuming so much lead.

I was so glad to find your site on soil pH and stuff. Spent most of last night trying to get info on adjust pH down. I am on limestone. Best read right across the net!!! And more hopeful too...

Interesting that you say that compost is the great equalizer... where I have dug out beds and layered material green, brown, manure and soil... over and over to desired height .... the plants have taken off! I have MONSTER size pumpkin etc compared to where planted elsewhere... hardly grew... and from same seedlings.

But I noticed my Moringa trees started showing chlorosis .... well I think it is chlorosis.... yellowing of lower leaves.... and I read this could be linked to pH if on limestone land. Not getting enough nutrients. Locked up. If sulphur is the answer and coal ash is rich in sulphur would this be harmful or helpful on such land? Wood ash is very alkaline... but coal ash is not. What do you think? I am also wondering about Epsom Salt... magnesium and sulphur... would this be good to add?

Was very interested to see the acidic range that potatoes love... hmmm.... no wonder mine were so small. Can remedy that in potato towers.

Seems like the happy medium is 6.5 for nutrient uptake.

Thank you for all the info. Was very helpful.

Chelle

chelle,
  The yellowing of lower leaves is more often a sign of running out of Nitrogen.  It is the upper new leaves that tend to Yellow due to pH lock of of things like Iron.  But with lower leaves on the Moringa yellowing, it seems to me that most of the lower leaves on mine did yellow some, it may be kinda natural to loose the bottom leaves.  My soil is sand and relatively acidic from the high amount of rainfall we get though too much irrigation water from the limestone aquifer can swing things up here.

There are many plants that like higher pH a bit.  Peppers seem fine with pH above 7 for me as does basil and rosemary and even tomatoes and salad greens seem to do fine where I have a higher pH so long as I can deal with the Iron lockout issue.  Often if you can make everything else right for the plants, the pH becomes less important (though you still probably won't find happy blueberries in limestone soil.)
I've heard that potatoes need either rather acid growing conditions or rather alkali since too neutral will allow scab to attack them.

Isn't compost great!!!

TCLynx wrote:
chelle,
  The yellowing of lower leaves is more often a sign of running out of Nitrogen.  It is the upper new leaves that tend to Yellow due to pH lock of of things like Iron.  But with lower leaves on the Moringa yellowing, it seems to me that most of the lower leaves on mine did yellow some, it may be kinda natural to loose the bottom leaves.  My soil is sand and relatively acidic from the high amount of rainfall we get though too much irrigation water from the limestone aquifer can swing things up here.

Thanks TC. Does seem to only be the lowest leaves. I am oppostie to you on pH but have found a local supplier of Elemental Sulphur which I might use around certain plants if they get back to me. Just wrote them. My iceberg roses are not giving many blooms. Maybe needs pH amendment.

There are many plants that like higher pH a bit.  Peppers seem fine with pH above 7 for me as does basil and rosemary and even tomatoes and salad greens seem to do fine where I have a higher pH so long as I can deal with the Iron lockout issue.  Often if you can make everything else right for the plants, the pH becomes less important (though you still probably won't find happy blueberries in limestone soil.)

How do you sort out iron lock-out? I see in my "lasagna" beds that most everything grows well.. think it is all the humus introduced as Paul spoke of. I have just read that leuceana [sp?] really likes a higher pH. Going to get some of that. Excellent. Many uses.

I've heard that potatoes need either rather acid growing conditions or rather alkali since too neutral will allow scab to attack them.

That is interesting. My potatoes grew well... the leaves I mean.... but when I went digging they were so small. New growing to me. Maybe I went digging too soon... had to remove the tower... was in the way.

Isn't compost great!!!

You betcha! 

Much of my knowledge about pH has a big more to do with Aquaponics and what I've learned there.  In aquaponics when the pH is too high, we usually use chelated (sp) Iron to help the plants get some before the hi pH locks it out.

The lasagna might work partly because each plant can find a layer that it really likes.

Any root growing along the interface between compost and lime-rich soil would be able to poke its rootlets a smidge one way or the other and find a wide range of pH, and along with that a wide range of mineral availability. I could imagine soil that is, overall, too poor in trace minerals to offer the proper balance at any one pH, but yet has plants growing well in it where they can reach various places where the local pH allows each mineral to be more available than average.

Compost is, among its many other talents, a chelating agent, so I think it will also latch onto minerals when they're available, and keep them relatively available even through subsequent shifts in pH.

TCLynx wrote:
Much of my knowledge about pH has a big more to do with Aquaponics and what I've learned there.  In aquaponics when the pH is too high, we usually use chelated (sp) Iron to help the plants get some before the hi pH locks it out.

I am pretty sure I will need to get some of that then when my AP is up and running. Will look around and see what is available.

I know that Travis Hughley (Barrelponics) uses a sort of "pre-pond" of acid leaves - particularly oak - but said that almost all fresh leaves are acid - to filter his water through before it going into the GBs. He also spoke of using Hydrochloric acid... but carefully... plain old pool acid. He is very experienced though so I would need to that only if really desperate I think. My Tilapia like this water so will have to see.

I may have located Elemental Sulphur (which is slow release) and might just put that in the GBs too.... and not just the soil. Lots to learn yet as I play around. Never realised until now though how important pH is even in soil.

Chelle

Joel Hollingsworth wrote:
The lasagna might work partly because each plant can find a layer that it really likes.

Any root growing along the interface between compost and lime-rich soil would be able to poke its rootlets a smidge one way or the other and find a wide range of pH, and along with that a wide range of mineral availability. I could imagine soil that is, overall, too poor in trace minerals to offer the proper balance at any one pH, but yet has plants growing well in it where they can reach various places where the local pH allows each mineral to be more available than average.

Compost is, among its many other talents, a chelating agent, so I think it will also latch onto minerals when they're available, and keep them relatively available even through subsequent shifts in pH.

Interesting. Seems to be so. The difference is phenomenal. I know that the soil is very rich because it is virgin bushveld... never been farmed before... and nice depth of topsoil... beautiful black stuff with a lovely tilth... but that probably the limestone base causes the pH to be too high. So introducing the layers of humus has really made the difference. Less selective in what does grow well. Different layers of pH... that could really be it.

Makes the hard work really well worth it. Will keep topping it up from the top too....if the bio-mass will let me in!  Just keep cutting it back as part of the humus. Lovely!

Chelle

Just read that Sulphur is poisonous to fish.... cannot put it in GBs in Aquaponics. Wouldn't risk even Elemental Suphur now.

Chelle

Chelle,
    I have used Iron Sulfate in my AP system in small quantities before I found a source of chelated Iron to use.

In appropriate doses, sulfur is probably safe enough but in really high doses, almost anything can become a poison.  I don't think adding enough sulfur to an AP system to significantly change the pH is going to be safe for fish.  (Especially if the high pH is due to the media being limestone.) 

As to soil pH.  I think in general, most people eventually come to the conclusion that to fight a naturally occurring pH very far is likely a loosing battle.  Trying to bring the pH of limestone down or trying to bring the pH of peat up is not going to be all that effective.  (at least until you have added so much stuff that is it like a pile of new soil on top, so ya might as well build raised beds and have done with it.)

You are probably far better off doing what you have been doing.  Building up "new" soil on top using lasagna methods.

Handy pH iPhone app to let you know pH range for individual plants or to work out what plants you can use if you don't want to alter pH of soil.  Look for "soil pH" at the app store.  Some of my listings vary from yours slightly.