How much lime do I need to add, how often do I need to spread lime, and can I just spread it on top of the soil without discing into the ground?

Your pH test will tell you how much lime to add. Be prepared to add several tons of lime. Generally, it will take several tons of lime per acre to raise the pH. And usually, once you spread the proper amount of lime to raise the pH to a 7.0, you may not have to add lime again for five years or more and then it will probably not be as much as you had to add initially. Lime needs to be disced or tilled into the ground. Lime setting on top of the ground can blow away or take virtually forever to wash into the soil and raise the pH.