The most common and most likely answer to this crossword clue is the 4 letter word AWNS
I've seen this crossword clue in The Daily Telegraph
A
W
N
S
More clues leading to the result AWNS
Buddy explains!
The straight part
We know that "they’re seen in fields of barley" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they’re seen in fields of barley = awns.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AWNS mean?
AWNS noun- The bristle or beard of barley, oats, grasses, etc., or any similar bristlelike appendage; arista.