Since I'm working with a curved surface, I can't just use draw on it like I would as a separate sketch and use a split line feature.

I also did the extrude mid surface method around the area where I want to select separately ensuring it was a closed sketch passing through the curved surface then  selecting the intersection within Split line as oppose to projection but still only allows me to select the entire curved surface. What gives?

I intend to chance a selected area of the curved surface to the texture to grass. 

BTW I am using version 2015-2016 edition

Thanks in advance.