How to Lower Turf Soil PH With Ammonium Sulfate

Take a soil sample and perform a soil test. You can find these at most garden centers. Follow the directions carefully to ensure the most accurate reading. The most effective kits are those that use dyes or a test pen to determine the pH. A more surefire method is to take a soil sample to a soil test laboratory or your county extension service.

Amend the soil prior to seeding or sodding for the best results. The maximum amount of sulfur is 5 lb. per 1,000 square feet and it needs to be applied in fall or spring. Load the sulfur into a rotary fertilizer and roll it across the soil then till it into the ground to a depth of 6 inches.

Test the soil again in 6 to 12 months because sulfur acts slowly and it will take time to change the pH or the soil. Experts recommend turf site preparation begin the fall before seeding or sodding.

Apply an ammonium sulfate fertilizer in spring and fall to cause slight acidification and lower turf pH levels. This is only a short term solution but will work if sod is already in place. The fertilizer is granular and is rolled on in a hopper with the appropriate setting. The amount of delivery is 0.8 lb. ammonium sulfate fertilizer to amend 100 square feet of loam or sandy loam soil. Soils that are silty loam require more to lower the pH at 2.4 pounds per 100 square feet.

Reapply the ammonium fertilizer annually after soil testing. Hard water used in irrigation will reverse the effects of the sulfur and the soils will go back to alkaline or neutral. Be careful to follow the directions because too much ammonium sulfate can burn the foliage and overstimulate the roots with too much nitrogen.