The tax on my farmland is about 3 dollars per acre per year. Last year, my revenue per acre was just under 650 dollars, and costs about 150. Considering I paid 4300 an acre, that's a healthy 11 percent ROI. Granted, I work the land myself in my spare time. It's not really an investment so much as a side business. I'm just saying, it's only a money pit if you're a dumb fucking hobby farmer who doesn't read.
Sure, they COULD raise taxes massively, but then food would become massively more expensive which would fuck the price of unskilled labor into the stratosphere.
So if you want to buy land just to lease out, as long as you're careful about to whom you lease, it will retain value and provide small, reliable ish returns.
EDIT: Now, granted, this is only true if you understand it, just as with any investment. Lots of dumbfucks like to buy up anything with dirt, tell themselves "hyuk, they ain't making more land" and lose their shirt.