coobie
Sweet corn is very resource intensive. It takes fertile ground, lots of N, nitrogen, and lots of water. Start with your soil and do a lot of amendments this fall. Do you compost? Chemical fertilizers alone will soon sour your soil. Also, you shouldn't grow corn perpetually on the same plot. Crop rotation.
Remember the fish. (referencing the Indians who gave us corn, beans, squash and so much more. We tend to forget the fish ie. the natural forms of fertilizing)
Finally, change up varieties until you find one that works well for your growing zone. Southern Michigan can take a good 120 day corn, as typically, the frost free days number that many. Your micro area may require you dial that back to a 100 day corn, give or take.