Again, your photos aren’t loading properly here in the forums, but since you did provide the location, 40.86746080353766, 30.33016200906703 to be correct, I can see the soccer goals, and it doesn’t seem to be on private property. However, the sheep being on Street View make it look as though its a field that gets used both for sports but grazing for farm animals, too, so it would be considered farmland.
At this point, you are welcome to appeal the rejection via Contribution Management and provide additional info as to why it meets criteria. You receive 2 appeals evry 20 days, and the more info you can provide the better.
I don’t know if you actually received a warning for this rejected nomination, but it you did receive a warning email, there is a link in it that allows you to submit an appeal. You can also find the link at the bottom of this page, which also has more info on what a warning is: