Crop circles are made by directing a stream of high pitch sound, high frequency vibration/energy that is, to a medium that can receive the sound/energy transfer and display the sound visually accordingly.
The beings who send these "crop circles" have bridged the sciences, in this case, sound & visuals. To them, it is one and the same. This is their way of sending radio transmissions, or, information, likely because we don't have anything advanced enough yet to pick up the frequencies they send so they chose to clutter the ground. Maybe because we are picking it up but not reaching the masses?
It can be done over vast distances with the right gear, sending the sound corresponding to the image desired.
It can be printed on most anything, but have a better life expectancy on wheat unlike on water or sand which instantly realigns or blows over.
Its this technology.
https://www.youtube.com/watch?v=wvJAgrUBF4w
But far more advanced.
These images are sent from alien satellites as a means of communication.
Some are easier to decode than others, a few contain basic ASCII codes and messages while most contains star constellations and the movements of heavenly bodies.
If you lurk /fringe/ and propagate that the creators of these images were humans, humans with sticks and ropes, you're either a big fat disinfo or have your head so far up your ass that you lick cognitive dissonance off your intestinal membrane for breakfast lunch and dinner.
The creators of these images are not humans of Terran origin and deciphering these images are of great importance.
They themselves does not contain schematics for new apparatuses, but they point us in the right direction, they speak of cosmic waves washing over the planet, they hint at Metatrons cube, secrets of quantum physics and suggest research in magnets, something humanity lacks and has not delved to much in.