How much sulfur is too much sulfur to lower PH?

[sepeters]

So, I have this friend who's been having trouble with the garden. Our soil is very alkaline, and so is the water, both about 8.5.

Obviously it needed to be amended to become more acid so veggies could be grown. The local co-op extension gave instructions to use sulfur to lower the soil pH to 5.5. I know they are the experts, but that seems pretty low to me, especially since the pH was achieved solely by using sulfur. We are developing several theories about the problems being experienced in said garden, and I am wondering if that might be too much sulfur. Could this be damaging at all?

I have used sulfur to lower my pH before and had only good experiences, but I did it incrementally over a few seasons and only lowered it to about 7.0 with the sulfur. I was able to eventually get it down around 6.7 (give or take) after several years with compost, etc.

I'm not at all sure this is the problem, just trying to narrow the options. If this is a problem, how would one go about fixing it? I'm guessing adding dolomite right away would only further complicate things. Not sure how to proceed. What do you guys think?

[imafan26]

I was cautioned not to try to change pH more than one point at a time and to add sulfur in stages. If you are using compost in the soil, the compost can help to buffer the pH depending on the type of soil you have to some extent.

Below is a link on how to change soil pH

It can take 6 months or more to see the results of the addition of sulfur and the changes are actually being made by the soil microorganisms. They do not work that fast and changing pH can upset the balance of microorganisms in the soil. Fungi like more alkaline conditions, bacteria are prevalent in more acid conditions.

Depending on what is making your soil alkaline in the first place, the effort may in the end be futile. If you have a limestone or coral base, you cannot really change that.

The best bet would be to grow what does better in alkaline conditions. You may be able to adjust the pH a little lower but to make and keep the soil acidic would not be cost effective.

If you want to grow plants that like acidity and you are willing to go the extra mile here a few things that you can do.

1. If your water is alkaline, you can install a whole house RO system. It will remove the excess minerals in the water and make the water less alkaline.
Either that or you could catch and use rain water for the garden.

2. Amend the garden with acidic organic matter. Make your compost with acidic feedstocks like oak leaves and pine, or add peat moss as part of your organic material. Add sulfur to the compost while it is cooling so by the time the compost is ready, the pH will be more acidic. You would have to test your basic compost and get a recommendation for the amount of sulfur to add to make it neutral. We did this to vermicast to get it neutral.

3. Grow acid loving crops like fruits and tomatoes in containers or raised beds.
It may be impractical to change the pH of the entire garden, but you may be able to control the pH of a bed or container by selecting the right media.

4. Nitrogen is lost faster in alkaline soils through volatization than in acidic soils. The good thing is that organic sources of nitrogen release slowly, but you may need to add more.

P.S. You will probably never have to add dolomite lime.

https://extension.usu.edu/files/publicat ... 003-02.pdf
https://www.grow-it-organically.com/chan ... il-ph.html

[rainbowgardener]

I agree that it is very difficult to permanently significantly change the pH of a whole garden. It is impossible if he keeps watering it with the pH 8.5 water! Another option for the water is rain barrels, so he can be watering with rain water.

I don't really know the answer to the rest of your question, but it certainly makes sense to me that adding enough sulfur to change the garden from 8.5 to 5.5 (! that's huge!) could have killed off a lot of micro-organisms and thrown the balance off. Veggies like slightly acid, but would be perfectly happy at 6.5.

[sepeters]

Thanks for the tips, guys! Unfortunately, the sulfur has already been added. When he told me how far he was instructed to lower it, I was shocked, and couldn't believe this advice came from our cooperative extension! I immediately thought this might be a major source of his problems, but wanted to see what others thought as well.

In my current garden I've been able to lower my pH to exactly 7.0 with compost, coffee grounds, other sources of organic matter. It is still not ideal, but the plants are doing fine. I know he needs to add some veggie compost, but at this point I'm afraid to tell him to do anything that could lower the pH any further. We'll see what we can do about rebuilding the microbial life in other ways for now.

An RO filter would be amazing, and I do like the idea of rain barrels, but they're somewhat impractical in our region. We only get an average of 8.3 inches of rain every year, so it wouldn't be enough to be effective. The hippie in me always wanted one anyway, though. Ha ha, maybe if we go together we can get BOGO RO filters? (I wish!)

[rainbowgardener]

Sorry about that, I wasn't thinking about AZ when I mentioned the rain barrels. But here's what Marlingardener in central TX says:

"Gardening in Texas nearly requires a rainwater catchment system. We have three 250 gal. fiberglass cubes, two that catch water off the barn roof and one that catches off the garage roof. We also have two 55 gal. barrels that get water off the house roof.
Our saved rainwater was all that took our gardens through the last two summers."

My Quaker Meeting got one of those 250 gal fiberglass cubes free from a company that uses them.

To be useful, you need to have more water storage than I do, since mine are refilled more often, but if you have the extra storage, it is even more important for you.

[sepeters]

Thanks, RBG! No need to apologize, you're just trying to help!
I'd like to have a rain barrel, even if it didn't collect lots of water, I agree it would be useful. The garden always looks amazing after it rains, it would be nice to have a store of water that isn't more alkaline than the soil! I just don't know where I'd put it, since I live in a condo and I've filled every available square inch of space with potted plants and my garden bed.
I know that I have a problem and recently starting attending PETC meetings. I'm going to def. recommend to my friend to see if he can get some barrels though; he's got a house!

[imafan26]

I am surprised the county agent said to try to lower the pH to 5.5. Unless your friend was asking to grow blueberries.

I would have thought that the agent would have recommended to add the sulfur in increments or to add peat moss instead.

As I have said, it takes time for pH to change. You won't see a lot of difference right away.

What kind of problems was your friend having?

[ElizabethB]

I am also surprized at the 5.5 recommendation unless that is to compensate for the high water pH. Rule or thumb is 1lb granulated sulfur per 100 square feet to lower the pH 1 point. That takes time (4-6 month) A quick fix is water soluble sulfur but you do need to apply in small doses and monitor the pH level (suggest a pH meter). It is not as stable as granular sulfur.

I did some pH adjustments for my Mother's hydrangeas (she wanted blue) and her blue berries. Using the recommended rate of granular sulfur her pH stabilized after the first year and has remained stable.

IDK what to say about the high water pH except to capture as much rain water as possible - tough to do in AZ.

Good luck

Just out of curiosity - how deep is your well?

When we first bought our home (1980s) we were outside of the city limits and on a water well - 150' deep drawing water at 60'. The sweetest water imaginable. Friends and famil who lived "in town" would come by to fill jugs with frresh, sweet water. Sigh - no longer have my well.

[sepeters]

Apparently the information on how to prepare the soil was obtained from the cooperative extension website, which I have to admit...I haven't visited, since I've only had minor troubles (mostly pest related.) I tried to access it after he told me that but couldn't get the dern page to load for some reason. I'm totally tech ignorant, so it's probably an operator error of some kind.

Lowering the pH so far to compensate for the high pH of our water makes sense....sort of. I mean, it would make more sense to me to address the issues separately, but I suppose you couldn't very well install an RO system if you have a huge farm.

Still have to test the pH again, so keep your fingers crossed guys! This might not even be the problem, but I am a paranoid worrier and like to consider all options, JIC! All of the plants he first started did well until he put them in the ground and then they all died. He said it was like they had been poisoned. We're still trying to figure it out. We'll test the pH and see where it's at. Also going to start either churning in some myccorhizal fungi or watering heavily with ACT.

Neither of us has a well on our property since we both live within city limits. I've got some cousins out in Maricopa who have a feed farm and used a well for many decades with excellent results, but apparently had to condemn it in the late 90s. I don't remember why, but have vague memories of someone becoming paralyzed...some sort of bacterial poisoning I think...I'll have to call grandma to get the details. Sorry, I'm rambling.

[sepeters]

Thank you for the link, Marlin! New information is good information! I tried to grow blueberries once and the results were disastrous! Now I know why! I did not know figs like alkalinity, but that would explain why my fig tree outgrew its container so quickly! I thought we'd have a house by the time it needed to go in the ground, and had to donate it my mother's elementary school. C'est la vie, no?

Oh, and BTW, regrading the well water: I had two situations mixed up. No one became paralyzed from the well, but they were getting sick. Apparently it had unsafe levels of arsenic. My Nana was very adamant that I clear that up, since she didn't want anyone thinking my family started a new polio outbreak.

[gixxerific]

Add some, no, no lots of compost, manure and other organic materials and deal with it. It will balance out a bit. But that drastic of a change is dangerous. That much sulfur is ugly.

End of story!

[ElizabethB]

Agree Gix - too much is not better.

[ruggr10]

How about you make them raised as either full raised beds or just slightly raised beds and bring in some fresh loam?

[PaulF]

A soil test by a reputable lab is the best way to go. And yes, the one point at a time is a good rule of thumb. I have an 8.2pH and fight it on a yearly basis. This year my test indicated my soil is out of balance and needs N to help out along with more organic material.

A really good agronomist explained that balance of nutrients is more important than just paying attention to pH. He put it this way: Think of a bucket with a compartment of all the nutrients your soil needs. Each compartment is of a different size of course, but if one compartment, several compartments are too full or empty, the bucket balanced on a pin on the bottom of the bucket, the bucket will tip. When the bucket tips, fertility dumps out. Too much of something will cost you in fertility; too little the same thing happens.

If you are for the most part in balance, you can grow good stuff. Less if you are out of whack. N, P and K are the main compartments. Work on that first. Organics and certain trace minerals and pH are next most.

By following soil test recommendations, you will get into balance.

[imafan26]

Paul, I like that analogy. Adding compost does help balance and buffer the soil to a great extent. But it does help if the compost is composed of acidic materials in alkaline soils.

The balance of other nutrients are also important as excesses of one nutrient can impair the availability of another.

For quite a while now it has become apparent that years of using synthetic and organic fertilizers, monoculture, modern farming practices (including animal farms), and simply adding fertilizers as a routine vs having soil tests done and adding only what is needed is causing problems.

Phosphorus from organic and inorganic sources are causing problems too because excess of any one element can adversely affect the availability of other elements. Excess phosphorus is another limiting factor of growth and can ultimately impact our water quality. pH, soil type, temperature, and rainfall all affect availability of nutrients.

https://aggieturf.tamu.edu/files-2005/ph ... Provin.pdf
https://www.ctahr.hawaii.edu/oc/freepubs/pdf/pnm1.pdf

[sepeters]

Haven't checked in on this thread for a while. Thanks to all again for the invaluable advice. After the initial sulfur, lots of acidic compost materials were added and *presto* things are looking good and well on their way and he should be able to get a dang good harvest out of the season. I think you guys were right on about the sulfur killing the beneficials and nutrients vs pH info.

In the long run, I think the sulfur will have helped, but it is most likely what caused the initial set back.

[imafan26]

Good that your friend's garden is looking good. The acidic compost probably is what helped. It is probably too soon to tell what the effect of the sulfur will be, that takes about 6 months before any effect will be noticed. The good thing is that more plants like acidic conditions than alkaline.

The soil microbes won't be totally killed off, from what I understand the acidic conditions will be make the soil fungi dominant rather than bacterial dominant. What that means in terms of how well plants grow, I haven't a clue, it seems that the makeup of the soil microbial community is impacted by pH, but the ecosystem as a whole impacts how well plants grow. Those ecosystems are made of many interlocking components and changes in one component may be counterbalanced by some other factor to some extent.

Breakdown in soil systems may not be apparent at first but may show up later. Just as mono culture farming had high yields for almost 30 years before the soil blew away in the dust bowl of the 1930's, when the ecosystem went past its' tipping point.

[Gary350]

I live in the Phoenix area too. Buy a pack of PH paper from China on ebay 99 cents free postage. PH paper also known as litmus paper.

Put sulfur on your soil, till it in, water every day for 2 weeks.

You can test the soil yourself.
Get 1 lb of tap water = 1 pint of water.
Get 1 lb of garden soil.
Test the water with the PH paper lets assume you get a reading of 8ph.
Mix the soil with the water then test it with PH paper again lets assume you get 7.5ph this time.
7.5 is the average reading.
If you mix 7ph soil with 8ph water you get an average reading of 7.5 ph.

Math formula = high PH + low PH divide by 2 = average PH

Soil PH = soil/water PH x 2 - water PH

Example. Assume water tests 8 PH and the soil/water mix tests 7 PH. 7x2-8=6ph

[gesx]

Hey guys. A wonderful discussion. I enjoyed reading every comment and learned a lot along the way. I realize this is an old discussion but would like to ad something in hopes that it wil benefit someone, or some people. The idea of catching rain water was,for the most part abandoned. From my understanding this was due to the small amount of rain received, and possibly having enough room for a catch system. I just want to point out, for those that don't know, it takes little rainfall to ad up to a lot in volume, when considering the average size home. I know everyone doesn't have an average size home. As such results will vary. A condo is sure to be different also. This is just an example and you can apply the math to come up w/your own results. Take a 1200 sq. ft home. Let's say it's 30'X40', with 1-1/2' overhangs and eves, and a 5' high ridge. That equates to 1483' sq. Now each 1" of rain, that roof will catch and ultimately deliver to you, would be 924gals. That's significant in itself. Multiply that by 8" and you've got quite a bit, even in the desert. As for storage one can only do so much, and different areas have different laws and ordinances. A suggestion, if possible and feasible, there's often room underground. Plastic barrels are capable of withstanding a fairly heavy load when stood up straight and buried w/a foot or so dirt on top of them. I have groups of 4 buried, in various locations, and though I don't recommend doing so, I have driven over them w/a 3/4 ton p/u, as well as a tractor, w/no problems at all. Again, I don't recommend doing so, but tell you that to show you that, if properly backfilled and covered, and placed in a location where it won't be exposed to heavy loads, you can often find a way to catch and save water. Hope this helps some. Good day and happy gardening!!