I am wondering the same thing but not limited to only corn , if we can master gardening directly in lawns without disturbing the lawns esthetic it could look really nice and clean before, during, after planting and harvesting.
Corn would be an excellent example of a desirable lawn vegetable. We likely just need to dial in the right nutrients so that the seed or transplant grows into a big productive plant. , While minimizing digging beyond the size of a plug, so that the effect is seamless. My idea is to dig a plug out, not big enough to show when looking at the lawn, but big enough to get some charged biochar , a bit of potting soil and compost down there with some worm castings, and then pop in a healthy plug , water it a bit frequently with some good tea. Maybe some bloodmeal or bat guano ,or something, can help with the nitrogen requirement. ( which Might be a while before it's dialed in)
As silly as it is, the thought occurs as some kind of veggie incognito grow plot for people living within the constraints of silly bylaws and home owners associations which would restrict people from having dug gardens or boxes. Requiring green grass that gets cut, etc. Many of us might agree that these kinds of restrictions are entirely unnacceptable. And presenting us with the challenge and the opportunity to do something about it.
I'm.sure if you put the corn in the right place, it will have an ornamental effect and not cause complaints. But as a tall plant, this may or may not bode well with those who still have a stick up their butt. Which brings me to think of other veggies like carrots, mesclun mixes , mint etc, growing amongst the grass... With the added benefit of looking like a dilligent puller of weeds to all the neighborhood stalkers .
I think if we try really hard, we can turn this into a functional method of growing some veggies. It truly is a.worth while endevour, as silly as it is, there are far too many people limited by silly rules that need countering, and beyond this, if we can master it on a lawn who knows where else this can come in handy, who knows what other plants might be magically made to appear on city lawns with frequent irrigation, and the like.