Where do I enter 'taxable grant' income reported in box 6 of a 1099-G?

I received a 1099-G from US Dept of Agriculture for subsidizing tree plantings and conducting a forest stand improvement on my farm.  The payment is listed in box 6 (taxable grants) of the 1099-G.  However, entering the payment in Box 6 is not an option in the form that opens when I attempt to add a 1099-G, only boxes 2, 7, & 9 appear.  Further, if I open the 1099-G form and add the payment manually to box 6, the 1099-G disappears from the list of 1099-G's for the farm.