I've long known that large expanses of corn such as in the Midwest and areas of the southeast (corn and rice) can evap to moderate or enhance broad areas of climate or warming (increases nighttime lows) in the summer. Late June 2 years ago when I went out to Dauphin Island, AL, as soon as the sun hit the corn, you could literally see the vapor coming off of it. It was neat to see. In years like this one where there has been a copious amounts of rain, that's what I struggle with also out here in the hardwoods of eastern Oklahoma. Many decades ago, there weren't such vast expanses of high evap crops or such intricate irrigation systems in either of these areas but I've yet to find a study stating the contribution to us average temperatures from agriculture. Odd.