I find that 38 hours per acre for corn figure a bit inflated as someone who use to plant 2 acres of corn each year using a 1901 corn planter and harvesting it by hand with my father. It never took the two of us more than a day to harvest the entirety of the corn, store it in our corn crib, and bundle all the corn stalks, while working at a fairly leisured pace. Tilling, fertilizing, and planting only took a day and only required one person for the first two, granted we did use a 1940 farmall tractor, but like I said its not like we were working at any real speed trying to get it done as if we needed it to survive. It was just a cheap and easy way to get corn to fatten up a cow or two before slaughter. It is also an absolutely miniscule amount of work compared to the amount of food it produced. Using 1900 corn yields (we didnt actualy weigh our own yields), it was over 3,000 pounds of corn, and it was likely much higher growing a more modern variety. Going by bulk grain corn prices at the local Tractor Supply the value rivals or exceeds the average local wage, and if it was sweet corn would surpass local wages multiple times over, so doesn't seem like a bad deal at all.