strange grass and soft partcile glitch, example image attached.

Hard to explain, but when viewing grass (terrain painted) in game or editor, and in the same view as a object with a particle shader applied to it, this happens (see attached images). The grass and particle shaded object don't need to clip to cause this, they just have to be in the same line of sight.

The example images show a cube with a particle shader applied(additive), and partcile mesh sun shafts also additive. This still happens when changed from additive to alpha blended or any of the other particle shader options apart from multiply but I think that is because the object becomes invisible.

I've tried different file formats for the grass textures, no luck though. Using linear colour space, and forward rendering. Unity V 5.1.1p4.

I have no idea how to resolve problem so any help or advice would be greatly appreciated.

Thank you!