This is from a very short story called “Fairyland,” by Darin Bradley. You can read the whole story here at Coffinmouth.
Here’s the snippet. It’s a terse little stream of images that add up to a quite clear picture before easing into character stuff:
A valley. Pastures, which had gone bad. Empty. Haze obscured the surrounding hills. It was what Gil had expected of The Bomb. An Indian Summer twinkling radioactive ejecta. Refracting sunbeams like farm dust or smog. Or burning magnesium. He thinks of his own ghosts, and wonders if they burned up somwhere else, in the past. Maybe the whole world was dead already. Maybe we were all eaten up and spat out in radioactive chunks.
(The story originally came to me via Snuffy‘s twitterfeed.)