Additions are sometimes necessary for depreciation or amortization, expenses related to income that Arizona doesn't tax, or when certain tax credits have been claimed. It's not clear, from the information you've provided, what this amount might reflect.
According to the line 17 instructions for Line Q in the Arizona Form 140 Resident Personal Income Tax Booklet at the Arizona Resident Personal Income Tax Booklet page:
Other adjustments may be necessary. For example, you must add-back expenses related to income that Arizona does not tax. If you have more than one Other Adjustment, add the amounts together and enter the total.
