I have been here before! I think these might be ancient maize storage cages during the harvesting process or as storage for cattle fodder.., no doubt someone will inform my enquiry!!
Difficult to see in the pic but wooden stakes mark the ditch so that farm vehicles do not 'plough on' into the dyke! These were in the opposite direction to the rusty cages. I love driving in open country... was making my way back onto the route from which I had accidentally deviated...
which reminds me of the story of my life!