Soil is alot closer to a ton per yard. So 1500lbs is a yard or less. And I assume he means one of them big bulk bags like theseI speculate the OP meant to type:
Will a b3030 lift a 150 pound bag of soil?
A 1,500 pound bag of soil might be 3 cubic yards in volume. Most compact tractor FEL buckets are 1/3 cubic yard or less.
The bag would have to be 1/4" thick or more for strength.