Why my particle system is rendering behind a standard shader?

Hello all,

I've been trying to create a sand storm that will cover the entire city in my scene.

However it covers several parts and leaves the ground uncovered - the ground has a standard shader material.

I've used the alphaBlendForground shader suggested here

I've tried to add this code as suggested here

Is there a way to have the particles render above all the other sorting layers? what am I missing in this regard?

P.S when I change the shaders rendering mode to"cutout", "fade" or "transparent" the particles will render above it. But I need the render mode of the ground to be opaque

Thanks!