Adventures of a Kernel of Wheat appeared in the Gregg Writer from February through April 1929. This was right before the anniversary manual was introduced in May 1929. The story is in 1916 pre-Anniversary shorthand.
The English source material was an uncopyrighted story that served as a promo for the wheat milling industry. I found an English-text copy of this story in brochure format online.
Link to the story: