Hey Kabirpunde and Imsopiv,
Thanks so much for the replies! Changing the directional light to movable did the trick! Also I added the grass node to the various textures that make up the corn and that gave it the right amount of movement. What I did so far to reduce the frame rate drop was deleted the corn to about 5 rows and added in simple planes with a rendered image of the corn to give the illusion of corn going off into the distance. I am also going to try culling the corn at a certain distance like Kabir said and see if that can reduce the drop even further. Thank you so much for the help!