I have typical heavy Denton clay soil. I recently prepared a planting bed for shrubs. I put lava sand, green sand, corn meal, and compost on the surface and tilled in to a depth of about 5 inches. I then put about four inches of shredded bark on the surface and planted my shrubs (according to Howard's instructions). I've since planted a few more shurbs and, when I dig into the soil, it smells very sour. Is there anything I can do except wait for the earthworms to do their thing?

Check your drainage first. Wet soil is often the cause for foul oders.
Tony M

All those things you tilled under the surface are meant to be used on the surface without tilling them in. Wet corn meal will really smell sour.

When you stop digging, the smell should go away.

I totally redid a huge flower bed (400 sqft) 2 years ago using basically the same method and it also stunk when I dug. It will go away. It is mainly the cornmeal. I had no ill effects from it as all my plants have thrived. As long as you have the proper drainage I wouldn't worry about the smell at all. It will go away soon!

Saw the same thing when I tilled cornmeal into my rose beds but a month later I could start a bait shop - the worms are so numerous and huge now that if you turn the top two inches you will find about a dozen per square foot just at the surface.... the cornmeal has worked wonderfully on black spot so hold yer nose and go with it!!! A little molasses sprayed in seems to make it break down faster.