There was an 'excess' of 10 bushels (over what was needed to fill the bin).
Eating anything 'in excess' [=in overly large amounts] can be bad for you.
The movie embraces all the worst 'excesses' of popular American culture.
(..) He'll be fast. Virtually invulnerable. Isolated. Alone. He will not be alone. He will never be alone. The energy input to Jor-El's quarters is now in excess. Our data indicates the loss is due to a misuse of energy. Investigate. And if the investigation proves correct? He knew the penalty he faced. (..)1978 Superman