An appealing image that subtly meets the challenge
You have a lovely landscape dominated by the vivid yellow crop and nicely broken up by the power line posts in an effective position that leads you into the darker background and ultimately the sky. As you say the sky is lacking in detail especially against the bright yellow foreground, however, I suspect that the subtlety of your 'technical flaw' may have proved too much for many voters here seeing a lovely landscape without recognising your 'imperfection'. As you will see from the results the most successful images are those with the most obvious flaws so this I think has affected your result although it is still very respectable.