For Your Consideration / Speculation

So, I was browsing the internet for my much needed fix of weirdness and I came across this little gem of a photo over at earthfiles.com. I think this is a very intriguing situation that has been presented. There are two new crop formations in the image, but also, there is a ghost formation that still lingers from the year previous. If all formations are being produced through mechanical means ( board and rope ) then what is the mechanism in that process that alters the soil in such a way that it still modifies the growth of the crops a year later? Where's an easy answer from Occam's razor when you need it? There doesn't seem to be any simple conclusion here.