Pure elemental sulfur might be cheaper than aluminum sulfate. I see there are sulfer products that are OMRI listed (organic).
Straight sulfur Is probably not very fast acting. Microbes gradually oxidize it and combine it with water, which in effect produces sulfuric acid (H2SO4). That immediately counteracts some of your alkaline water (OH-).
The most finely powdered sulfur you can get is better - or rather, faster. Whatever is cheapest is probably best. I see "CSC Wettable Sulfur - EPA Approved for Feedstock" and a fancier products called "Disper-Sul® ". $2 to $4 per pound. 99.5%+ Ground Yellow Sulfur Powder
In the lab, it was called "flowers of sulfur" but that might be ancient terminology.
HERE we go!
A 50 pound bag for $22.50. 45 cents per pound sounds better.
http://www.arbico-organics.com...
"TIGER 90 CR® Organic Sulphur 0-0-0-90 is ideal for soil amendment purposes when a soil test result shows a high pH (above 7.0 and especially above 8), as well as high sodium and high lime (above 1.0%). Soil with such a high pH value is considered alkaline, and its high pH value causes essential nutrients to be unavailable for crops. One of the most cost-effective ways to lower pH is to apply Tiger Organic 0-0-0-90, a granulated product made up of thousands of tiny particles of sulfur per granule. Tiger 90 CR is mixed with Bentonite clay in a special time-release formula. It is OMRI listed and WSDA registered for use in organic farming.
As TIGER 90 CR® Organic Sulphur decomposes and lowers your soil pH, it will react with the free lime in the soil, which will add gypsum (high in calcium) to the soil and free up the sodium to be leached out by watering.."
