I think that George put lime in his yard pretty recently, not right after this case broke. That's the way I read it earlier today.
Did you all not read the posts yesterday by the dog trainer? She said that if Caylee had been buried in the yard, that the dogs would have gone crazy. They just alerted, probably from a very mild odor that humans wouldn't even be able to smell. She said that probably it was an article of clothes or maybe the gas cans that had been set down on the ground long enough for some of the scent to apply to the ground. That's why they didn't dig anywhere in the back yard. It was not a strong odor like it would have been if the decomposing body had been in the yard for several days.