It looks horrid, it scars the landscape and I've always presumed that it was a way of improving the already intensive market garden type crops produced in the Southern ends of Spain - tomatoes, peppers, cucumbers, aubergines and the like.
We had a bit of a trip out today to the town of Aguilas at the Southern end of Murcia, just a stone's throw from the border with the province of Almeria in the region of Andalucia and, guess what? Lots of plastic.
It's odd. When I very first came to Spain some thirty or more years ago even I noticed the rough and ready looking veg. It was easy to think that those scarred and blemished tomatoes or battered potatoes were grown on a peasant smallholding. Who knows it may even have been true then but I don't think it is anymore. The stuff in Spanish supermarkets is just as uniform and just as tasteless as the stuff I remember buying in the UK.
I've just been Googling the plastic sheeting and it reads as though most of the stuff that is spawned beneath it is for Northern European, particularly British supermarkets. In some cases the structures simply help to prevent wind damage and to allow more efficient use of water, chemicals and light but more often the plastic produces a totally enclosed environment where plants are grown in puffed up volcanic stone into which precise quantities of liquid fertiliser are dribbled.
Romantic stuff eh?