Lowering soil pH

According to my soil test, my pH is 7.5. I read that I could put ammonium sulphate on the soil to lower the pH but I don't know the details. Do you apply it in late fall or early spring? Does it leach out? I need a way to permanently lower the pH. Any advice would be appreciated. Thank you in advance.

Margo Tilton

What are you trying to grow in the area? Are you having difficulty getting something pH-specific to grow there?

Thank you for your reply. It just seems like everything I'm planting is more yellowish than they need to be. The soil test also said my soil was deficient in nitrogen and phosphorus.

Margo Tilton

Solving that problem involves a lot of complexity, and more education than a docter needs. There's one man who seems to have purty much solved it and that man has passed away now, he studied under Einstine when young and had simular mind capacity. When he tried to teach what he had learned from his research nobody would credit it because he talked too far over their heads and used commen terms in his own odd way. in his later life a few men started listening to him, and those men have written a few books. But several of those books I'd say are so technical they're beyond the comprehension of maybe 95% of people. He did things with plants that farmers don't even dream about. Like a crop of alphalfa 20 ft tall, a carrot that was about 3x6 ft in size, watermelons that keep unrefrigerated for a year, beans that go from seed to harvest in 17 days, and all produce so sweet and delicious it's way beyond normal. all done with fertility management.
I've tried to learn all i can from the books and I'll try to say a little. First; PH may-or may not, tell you how much calcium is in the soil, as there are other things that can drive up the PH. If you get a test for calcium, (preferably a soluble test, using the morgan extract solution) and it shows less than 3000 lb per acre. (ideal calcium level for reasonable crop yeald) then add high calcium ag lime in an amount based on the soil test no matter what the PH is.
(keeping in mind that most lime is course and will not be immediatly soluble, so a lot more can be added and it'll become availible slowly over several years)
Second; phosphate needs to be 400 lb per acre on the soluble test, the only way to get enough is to use something like soft rock phosphate, chemical phosphate sources won't give any where near enough. (bone meal works on a very small scale) Phosphate works as a catalist for carrying all other minerals into the plants, if there's not enough of it the nitrogen takes over as catalist, and that makes poor quality produce that won't taste good and the bugs and deseases will try to take it out.
Third: with both of those in place, then nitrogen is needed at a rate of about 80 lb per ac. just about any kind of nitrogen will work. Then the PH balance can be managed according to what effect is desired in the growing crop. alcaline for leaf growth and acid for seed and fruit growth. Nitrogen gets used up rapidly, especially as the plants get big, so more is usually added during the season.
Then there's the role of carbon, a regulater and maintainer of all soil chemistry, it will grab nitrogen from wherever it comes from, and feed it to the plants as needed, preventing leaching. Carbon is the main element in humate which is the active end product of organic matter breakdown, for small scale any sort of compost works good, for large scale humate can be bought as liquid and sprayed on at a light rate.
So nitrogen will leach and be lost if there's not enough of all 4 of the previous elements, especially carbon. That's the problem in big farming areas, nitrates in the ground water, that's the farmer's money down there that should have stayed in the top foot of ground and fed his crop.
Because they don't study how to manage their soil they're loosing money and contaminating the ground water.
Well, that's a start, Pike lab supply in Main and International ag labs in MN both do the soluble tests. soft rock phosphate can be gotten in large quantity from canton mills in MN. I don't really know where to get it in small amounts for reasonable price, shipping kind of drives the price of it too high even though a 50lb bag is only around $6. it's around $3.50 a bag + shipping if gotten by the ton.
I've been trying commercial scale production on and off for years, but now I'm going at it more seriously, reciently got an old refrigerated truck for delivery of produce. Plan to grow salad veggies. When I did 2 acres of summer squash, at one point we were getting a lot of rain, and the wholesaler i was selling to told me all the other squash growers had given up and plowed under because the squash was rotting with the rain. I saw them starting to rot, and because I had studied fertility management I knew what to do to stop it and get production going again. (rain dilutes soil energy, just needs a boost, I threw on an extra dose of amonia sulfate between the rows, so simple.) So I ended up being the only grower in the area and consequently the price went up a couple dollars a box.

Mtilton, A pH of 7.5 is within the range of most vegetables. It is close to neutral. Did you have a professional soil tests, the home kits are notoriously inaccurate. Asuming that you want to grow acid loving plants, here is no way to permanently lower the pH, you will have to amend on a more or less regular basis. Elemental Sulphur woks fairly well, acidic fertilizers like ammonium sulphate give a fast break (Miracid). Decaying organic matter like oak leaves works well. There are prepared soil acidifiers sold at most nurseries for acid loving plants. These are very soluble and work fast. I f vegetables are your aim however, Just get your nitrogen and phosphorus counts up to standard and you should be fine. Yellowing is most often a nitrogen deficiency which can be corrected by either regular or "organic" fertilizers. There are also multiple choices for phophorus, I prefer super phosphate ( used to be called acid phosphate) because it is phosphate bearing rock that has been processed to concentrate the the phosphorus content). In chemical terms plants need nitrates and phosphates, every thing has to break down into these radicals for plant uptake.

Lowering pH is much more trickier than adding lime to raise pH. Adding sulphur is a very temporary fix- one of the best things to do is add lots and lots of organic matter yearly.

Here is an article that explains it very well. It talks about landscape plants but you will get an idea of what you are dealing with.

The problem with alkaline soils is that they tie up micronutrients so you have to watch out for deficiencies of iron, manganese, etc. Micronutrient foliar sprays are sometimes recommended.

My pH is in the range of 7.4 to 7.8 --which is common where I live--it is a never-ending problem but alot of compost helps.

By the way is this one of those home-test of pH? Some people say they are not accurate. You can get a free soil pH test done at most extension offices just to be sure that the reading is correct.

http://edis.ifas.ufl.edu/MG092

Thank you for your replies. I had a professional soil test done by my county extension.office. At this stage - my second year of growing vegetables - the organic content of my soil is almost nil. My soil looks lifeless, pale brown and very dusty. I'm still learning and I'm not going to stop because of this year's poor-looking growth!

mtilton.... sounds like your soil is all worn out, BUT...you CAN revive it!!!
Just keep adding "organic materials"... grass clippings (without herbicide residues), compost, composted cow manure, kitchen waste, etc... and it WILL steadily improve. Meanwhile .... keep on gardening!!! Conditions will improve but it takes a while. I am originally from Elk City out in extreme western OK and I know the *HOT* weather of summer literally consumes (burns up) the organic matter in the soil so you "gotta" keep adding it. You WILL see an improvement & the pH will normalize and gardening results will improve!!!!!!

GOOD LUCK.......
LarryD

I read that coffee grounds are somewhat acidic. Perhaps you can add some into your soil.

we accedently spilled some 0-20-0 (single super phosphate) beside a blueberry bush and it grew a lot faster and bigger than the others that got the usual dose. 0-20-0 is not readaly availible last i knew, we had to special order it. but it's a good acidifier, 12% sulfate and 20% phosphate. have to watch the lable, I've heard sometimes they'll just dilute the 0-46-0 and call it 0-20-0, but it won't have the sulfate and act's different in the soil.
We can get really big yealds by putting on a lot of lime, growing a crop fast with high energy, then switching the ph balance with 0-20-0 about the time it starts to bloom.