Help with Grass!

Hello everyone,

I am a beginner to Blender, trying to build a scene to be used as a backdrop. I followed this tutorial to make grass:

The first time I tried it, it worked. But I noticed something that I wanted to fix, so I put the original plane on a different layer and started over with a new plane. However, the grass on the original plane disappeared, and no matter what I try, nothing is showing up on the new plane.

Since I’m a beginner, I am not quite sure how to trouble shoot. Please help!!

Here’s the blend file: https://www.sendspace.com/file/36u7pz