Buying a ranch in the way you suggest to do it would instantly raise suspicions since the fiat amount you are going to pay for the ranch would be substantially below the average market price of similar ranches around there.
Large ranches (1000+ hectares) especially in Third World countries tend to be very illiquid (your only buyers are the super wealthy but they don't want to invest in Third World banana republics) so prices paid can vary a lot when the seller is desperate, the neighboring land hasn't been sold for generations, and it is a common practice in Third World countries to declare the taxable value much lower than the price paid.
Even if we completely neglect the question why you would want to buy a ranch there, I still strongly suspect that it would be far better to spend some time and sell your Bitcoin stash in small portions for fiat (and withdraw money later as cash) without attracting a lot of attention from sniffing agencies, and then buy that wretched ranch directly with cash. If you buy it with bitcoins today, how can you be sure that the former owner won't run tomorrow to convert all these bitcoins at once to fiat, totally betraying himself?
And then he gets caught and points his finger at you