Add 1 cup of lime/cf of mix.
This of course AFTER the bale is expanded (fluffed out). A 3.8cf bale of Promix when expanded comes out to close to 7cf. So, 7 cups of lime for the entire bale.
An easier way is this. A cf is ~7.5 gallons. I'll fill 3-5 gallon buckets (15 gallons), with fluffed out mix. This equals 2cf and I'll add 2cups of lime and mix it all in in a wheelbarrow or large tub or whatever. Much easier to work with than a entire bale.
Wet