Why does turbo tax include my pension payments as income on my Alabama state tax return? I thought that pension payments are non taxable for Alabama?

It depends on the type of pension that you receive. Review the Income Exempt from Alabama Income Taxation to make sure your pension falls into one of the categories that is exempt from income for AL. 

You can check this list If you receive your pension from a Defined Benefit Retirement Plan.  You can also call the Individual Income Tax information line for the AL Department of Revenue at 334-242-1170, Option #1 to find out if your pension is exempt.