Yes, I use it all the time. However, I use the RESIN SAND product, not the plain modelling paste. Anything that's water based will saturate cardboard and eventually will warp, so don't go there. Use foamcore instead of cardboard. The paste will stick to that.
For ground in a diorama, I use this formula.
1 Scoop out half the jar and place it into an empty jar of the same size. Save the empty jars and reuse them.
2 Use a cheap 2 oz acryllic paint (Folkart, Ceramcoat, etc) and pour 1 oz into each jar. I use Chocolate Brown. Mix up both jars until there is no more white color left in the paste. This avoids 2 steps. One, you don't have to paint the ground once it's applied. And two, cracks or breakage will show brown, not whte so there are no repairs to do.
3 Mix a shot glass full of sand into each jar. This will tighten up the mixture and make it grainy.
4 Mix a shot glass full of Woodlands Scenic medium ballast (color doesn't matter) into each jar. These are your rocks.
5 Drop a dollop of white glue into the mixture. About a shot glass into each jar
6 Let stand overnight WITHOUT the jar lid on. At this point it's goo. Letting it air dry will bring it back to paste.
7 Mix it up again and cover the jars tightly. You now have 2 full jars of ground.
OK, this is your basic ground cover. It will stick to almost anything and everything sticks to it. Use a cheap set of of artist's trowels to spread the mix where ever you wish to place it. Spring for the metal set, the plastic one will break. Michaels sells these for a couple of bucks, use a coupon for added savings. If your mixture dries out, you can bring it back to life with plain tap water.
I've been using this receipe for over 20 years and it's a product of much trial and error. I use it on all my scratchbuilt pieces and all of my figures that require basing. It takes drybrushing amazingly well and any sort of ground foam or static grass will cling to it. Give it a shot.