As stated already, these pictures, as a whole, lack a sense of focus/main subject. Basically, there's just too much going on in the pictures, they're too busy.
Individually:
1. Lacks contrast. The tire seems to blend in with the hay. Perhaps a different angle or some PP?
2. Liking the composition and contrast with the white tire. However, a tighter crop would have made more impact.
3. Pot is blown out. Again, a tighter crop would have been nice.
4. My eyes want to see the mailbox with the numbers, but it's the mailbox that's in the front that's in focus. Again, lacking a main subject.
Overall, I like how sharp the pictures are.