There are isotopes distributed evenly throughout the crop anomalies which aren't found anywhere in nature. Nowhere, certainly not a field. Aren't a product of Mother Nature.

They seem to be similar to those suspected to be in landing pads of alien spaceships.

And waffle-stomper boots.

Clearly either very smart aliens or very dumb terrestrials, who may be inhabited by aliens who are communicating with the folks with the landing pads.

In fact, the waffle-stompers they are wearing might be made out of recycled landing pads, much the way some sandals are made from old tires. Aliens are well-known as being very efficient with materials and energy. Recycling son-of-bitches, they are. Recycle their little hearts out. Entertain themselves on long trips thinking of ways to better recycle.

That's gotta be it.

Arf