Back in February I did find a hint about the OP's request "Brown fields are empty where green corn was growing..". I found the first line on a website as a photo caption: Renew and Remember - Yesterday's Treasures Enjoyed Today (under last picture on the page).

I emailed the webmaster Beverley (Hello and welcome to Minnesota's North Shore of Lake Superior) on the 28th Feb and had forgotten about it, but today I had a reply as follows:

"Hello Mick,

I will look for the rest of the song....off hand I don't remember where I found it. I will keep this in mind and look around in my old music books and get back to you if I find it."

So we may yet solve another mystery of the ages!.

Isn't the internet full of nice helpful people, who'll take time out for people they've never met. (This is Mudcat! Preaching to the converted!)

Mick