Oh, it is called Raps, in case you're wondering (Brassica napus subsp. napus), an agricultural plant which conquered the fields of Austria in the last few decades - used both as an oil plant and as green fodder, or even only as a green fertiliser (for that you don't wait till the fruit are ripe - you plough the fields when the plant's in full growth, to fertilise the soil).
Also Raps has become one of the favourite motives for photographers, so really this is nothing special at all, it is one of a hundred thousands*) Raps photos. Browse the net for more if you like.
*) Well - more than a million in fact; try googling.
