Calculating mixing rate of ammonium sulfate for blueberries
Mrclint was kind enough to post the link below concerning blueberry fertilization with ammonium sulfate, AS, 21-0-0.
If I'm reading correctly it says that at rates higher than 1.0 g/liter AS becomes a salt problem when growing blueberries. So I'm cutting that in half to provide a safety margin. That equals rounded off ~2 grams per gallon. AS weights 4.6 g per teaspoon. The rate I've quoted before was about one teaspoon per 2.5 gallon jug. That still seems about right and about 0.5 g/liter.
More accurate calculations says 2.5 gal equals 9.45 liter. So 1.0 teaspoon AS (4.6g) diluted in 2.5 gal equals 0.49 g/liter.
I know that's not real easy to follow but that's my calculation.
So I think 1 teaspoon AS per 2.5 gal water is a safe rate on blueberries in pots if there is a decent leaching fraction. It's been working for me and this literature says it's safe if properly used.
Here is a link that might be useful: Ammonium sulfate on blueberries