You can't tax "the land". You tax the owner. The money doesn't come from the land but whatever source of income the owner has. That's what you are really taxing.

To actually tax the land, the owner needs to sell it, but who is going to buy taxed land? You are forced to sell it to pay the tax.

So taxed land, in the end, loses value, because it's sold more and bought less, and the source of income goes away, because he was forced to sell the land.