Strange, white circlets - Kübekháza, Hungary

Even not sure whether these are real somethings painted (poured) on the ploughfield or some kind of satellite imagery artifacts... (?)



white circlets on the field Kbekhza.kmz (923 B)

Probably some agricultural, soil quality upgrading process... (?)

I can imagine that what we see is the preparation works phase of some soil liming method, where doses of whitewash (or other blend of mineral soil improver) already been poured on the ground manually from a trailer.

...

Any other ideas?

Thanks!

G