This is one of the most impressive renders I've seen for a long time. It's done by a guy called Peter Guthrie ( link ) Apparently there are 20 000 clumps of grass and 1000 flowers in the scene! Uses VrayProxy and some sort of scattering...The good news is that he is going to make a tutorial on this ( link )
3D and V-Ray tutorials, news, experiments. And some Swift too.