Preparing or Upgrading Your Orchard Site - Growing Organic Orchard Fruits - page 121

Adapted from Cornell University and Oregon State University
guidelines. Do not add more than 3,000 pounds of sulfur per acre per
year.
Adding the sulfur. The best approach to lowering soil pH is to move slowly
and conservatively. Deciding how much sulfur to add is often difficult be-
cause of the factors mentioned above and the strong influence of soil type
and original soil pH. Table 4.1 ➔ provides estimates of how much elemental
sulfur you will need to lower the pH of alkaline soils to between pH 6 and 7.
The more finely ground the sulfur, the more quickly it will react in the soil to
lower pH.
Avoid adding excessive sulfur and acidifying the soil too much. In no case
should you add more than 3,000 pounds of elemental sulfur per acre at one
time, regardless of the amounts listed in this or any other table. If you need
to add more than 3,000 pounds of sulfur per acre, you should do so in stages
over a period of several years. Allow time for the sulfur to be metabolized
and for the soil pH to stabilize, processes that can take 2 years or more from