How to get rid of the smell of rotted grass?

don't quite get the question the grass was covered for one week and is now rotting but gone at same time ?

if the grass is in the ground under where covered rake up so standing upright and mow the grass.

could be soil maybe long shot stick garden fork all over affected area to make deep holes where tynes went in as will help soil if that is real problem.

or if you have a big pile of rotting grass smelling bad add carbon in the form of leaves or chopped up paper and cardboard and turn over to let air get to it

throw grass seeds down and the grass will grow again smell will go away.boy do i know that smell it is horrifying.