The Ag PhD Harvest Loss Calculator helps you determine how much of your crop you are leaving in the field after harvest. Simply select your crop and input the number of seeds/kernels you count on the ground in a square foot. The app returns a harvest loss calculation in both bushels per acre and pounds per acre. From Ag PhD - Information for Agriculture. For more agriculture and farm info, watch Ag PhD TV weekly with hosts Brian and Darren Hefty.