Put the summary of the bug you're having here

What I expected to happen was...:
I expected to walk slowly on the tilled ground as you do on the normal ground. (the grass is tilled by a shovel)

What actually happened was...:
I walked on the powdered snow like nothing was there I received no slowdown effect
Describe what happened here
I walked the normal Minecraft speed on the tilled ground with the powdered snow covering it

Steps to Reproduce:
1. Till the ground with a shovel ( right-click)
2. Place powdered snow on the tilled ground
3. walk on it and receive no slow down effect