My soil test shows a high Ph-and high Sulfur--(Sulfur is supposed to lower Ph)
How can this be?


Maybe the student who did your test was out for the weekend and you have a Monday result. No joke.....these tests are sometimes all over the ball park for some reasons we never understand . Call your testing institution and ask the same question. You may get a re-do. If anything is to far out of line with what you expect never never ever trust just one test from a single testing site. Makes sense too. Follow one bad test and screw up your soil for ten years!

Here in the East we have farm agents close at hand who can be contacted for guidance with test in hand.

This message was edited Oct 23, 2010 11:35 AM

Bay City, MI(Zone 6a)

It's not unusual for soils with high sulfur content to show high pH. The sulfur levels simply indicate the soil is high in sulfates. Case in point - MgSO4 (magnesium sulfate/Epsom salts) and/or CaSO4 (calcium sulphate/gypsum) will elevate S levels with no significant chance in pH. The elevated pH levels could be caused by high lime CaCO3 (calcium carbonate) levels.

What they might suggest you do, depends on the rest of your soil analysis. Some options would be to add more S, or possibly FeSO4 (iron sulfate). The H2SO4 (sulfuric acid) released would combine with the lime to make pH neutral CaSO4.

LOTS of organic matter would be very beneficial in bringing the pH down, and is, IMO, the best place to start.



Thanks folks --- I will contact the local agent and in the meantime add lots of organic matter as it is a high clay content soil--good organic matter can never hurt.

Helena, MT

VORTREKER, I would agree with doc's comment on laboratory results for pH as well. Typically this analysis can be performed by the least qualified of the laboratory personnel who are not always diligent. Also, pH is an unstable reading, particularly in solutions which should be read within 15 minutes of taking the sample to be accurate. Personally I think most gardeners are just as qualified to take their own pH readings with a simple chemetrics test kit. Actually litmus paper is probably as accurate as a pH analysis run by most labs including your local extension agent.

If your garden is of any size you may even want to invest in a test kit which will do N, P & K as well. I am still an advocate of using a good ag lab for an annual spring test of your garden for usually around $25.00. This is a wise investment again for those of use with a large plot. If you choose to do this the best procedure is to take about ten sames from 0 to 6 inches and add them together in a soils bag from the lab, or a clean pint bottle. The lab will further blend these samples before testing.

As for using your local ag agent I leave that to you. In most cases these are good and helpful people, but some are not interested in the local gardeners and their problems. Mine is an excellent example of the later. It's like seeing a doctor about a serious illness. You may want a second opinion if in doubt. I review laboratory land application reports as part of my business, and I do occasionally find mistakes, so no one is perfect.


Austin, TX(Zone 8b)

You might take a look at the soil maps for your area, but there's plenty of limestone and chalk up there.

Even if the county agent is geared towards large scale agriculture rather than home production, they're almost certainly familiar with your area's soil. (I don'tknow in other states, but fwiw, here a lot of times the Master Gardener Association would be the more appropriate resource for home gardens, with the staff sticking to larger producers.)

Let us know what you find out...

Allen Park, MI(Zone 6a)

You might want to ask for a retest.
Here in Michigan, Michigan State holds the original samples for a period in case a retest is requested.



My experience with the Ag. Agent for our area was negative. He knows nothing about organic practices and furthermore informed myself and another orgainc person that we had ruined our soil. What's worse he does not want to fool with home gardeners and certainly not serious organic growers. He is the academic and administrative leader of our Master Gardeners Group. That about wraps it up....right up to the base of a big stone wall. I have names for him unacceptable for use on this site. If he were an employee of mine he would be fired on general principle. LOL

Allen Park, MI(Zone 6a)

That's unfortunate, we have an excellent agent here.
You need to write a letter or email the head of the PA extension and let them know how you feel.


There are a lot of farmers (Dutch) that won't let him on their farms. There are some other farmers that go to the gentleman agent in the next county for advise. He is politically well seated and is going to retire in two years. No one I know wants to rock the boat.

Glenwood Springs, CO(Zone 5b)


You actually can have a lot of elemental sulfur in your soil and have a high pH!

If you don't have an abundance of sulfur reducing bacteria in your soil, the sulphur will not go through the sulfur cycle. Some bacteria convert sulfur to sulfate then to hydrogen sulfide, (under anaerobic conditions). When hydrogen sulfide is combined with water it produces a weak acid.

If you combine sulfer and oxygen at high temperatures you get sulfer dioxide. Add water, and you have sulfuric acid. A very strong acid.

Sulfer is essential to cell construction and growth in plants.

We tend to throw around terms like acidic, basic & alkaline when talking about soil. The science of soil pH will make your head swim. I am still trying to figure out a number of things.

You can never go wrong adding more organic matter to the soil!

Talk to your county ag agent, he may be able to help you if the pH of your soil is above 7.4.

You may want to try adding acidified cotton boll compost produced by Back to Nature of Slaton, TX.

Your humble Oberschiesmeister,


This message was edited Oct 26, 2010 4:28 PM



Thanks--you are correct that soil science can make your head swim and I have seen PhD's strongly disagree on the same set of facts.
My soil pH is 8.5 (confirmed) and is heavy black clay--this scared me to death when I moved here a year ago but I had a good spring vegetable garden and the best fall garden I have had in 40+ years. So I think I will stop worrying-add lots of organic matter--and just plant things!!! :)


Yes indeed and we have seen the same soil test sent to five different labs come up with significantly different test readings. I would agree that a soil test for a healthy patch person using organic principles may be the least important expense of gardening.

I would not however agree that one should forget about the organic matter and just plant things. Good common sense allmost totally ignored by commercial growers would lead one to understand that when you take away from the biological community by maintaining crops you must so some simple things in exchange. One you absolutely need to rotate the crops, Two you need to return soil biology and mineralology used by the crops and one needs to reduce the ripping and tearing up of the top six or eight inches of soil.

Any other approach is breaking down the health of the soil leading to destruction by poor management. One might laugh but the simple observation of increasing worm counts which is the result of adding to the organic content of the soil....thus more worm casts....the soil's best fertilizer... is by far the most important fact. This statement assumes that there is no single area difficulty that is commonly needing needing proven adjustment.

We in general need to just stop using man made salts called fertilizer, greatly reduce the use of cides and increase our attention to the common sense management of a healthy patch. It does not take rocket science to figure this all out.

Austin, TX(Zone 8b)

I think Vortreker was saying add organic matter and not fret further about the chemical analysis.

You might find this info about vertisoils interesting (Scroll down to find "Vertisoil example #1" to flip through some photos, including texas. A lot of times people describe this soil as "heavy" clay, because it is hard as rock when it's dry, and sticky like gumbo when it's wet. But the key thing is the extent to which it expands and contracts as it passes between those two states. It's dang near impossible to work on your schedule, but "The high capacity of Vertisols for shrink-swell creates the large cracks found in these soils... Surface material accumulates in these cracks during the dry season and is "swallowed" by the soil in the wet season, creating the self-mixing action of Vertisols." Which results in pretty good soil for growing grass and small things (that won't fall over as the soil shifts).


I have marveled at your soil in the Hill Country of Texas where I have spent most days enjoying a hunt and a few days slipping and a sliding in your clay...ish type soil. I have seen acres of grain to my amazed and simple mind. I did not expect to see that. When you get rain that soil abounds with healthy and mixed weeds that the wild life thrives upon.


--thanks--that is what I was trying to say.
I bought some very expensive "soil" from Good Earth because, when I moved here, I wanted to garden in a hurry and this North Central Texas soil "looked" awful" and the soil test "confirmed" that I was really doomed--LOL.
The "soil" (dirt) that I bought from Good earth and put in some raised beds was purportedly composted by a fellow that had 2 PhD's in soil science.
The veggies in the raised beds of the "scientifically" designed soil barely survived--the veggies in the (sorry-low down-unscientific-red neck- Texas muck)-looked great.
I am not knocking educated folks----(I have a doctorate in medicine)--but what I have concluded is "let nature take it's course"--After all nature has been at it awhile longer than us mortals.
I'm going the "add organic" route.
If a veggie plant wants to grow in in my sticky-yucky-overly alkaline muck--then I will not interfere.

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