First, this never happens, and certainly is not what's been happening for decades now in the US with the Fed printing money, so it's not a very relevant thought experiment.
Second, taking your scenario as given for the sake of argument, what was stopping the unemployed people from cultivating the uninhabited farmland before? Was it the absence of money, or the fact that they didn't own the farmland?
In other words, the real operative point in your thought experiment is not the government printing money, but the government giving tangible resources (uninhabited farmland) to a group of unemployed people, so that they will produce something of value from it. The money is really incidental: once they start producing more food than they can consume themselves, they will be able to acquire their own money by selling the excess. The initial printed money is really more like a one-time grant of working capital, so they can buy enough initial supplies to get the operation going. And money doesn't even have to be printed for that: the government could just allocate some tax revenue to it.
Third, in our actual system as it actually works, who does get newly printed money? Is it unemployed people who could be doing productive work but aren't? That was perhaps true for COVID relief checks--although those didn't really enable anyone to go back to work, they enabled people to stay out of work, not producing anything, for longer--but in any case those don't actually add up to a lot in terms of the total US money supply. The vast majority of the money the Fed prints goes to financial institutions, and the only thing whose "production" is increased by that printed money is loans. Those loans, since they are mostly mortgages, will certainly redirect productive capacity in the economy (so we build more McMansions and commercial office buildings that sit empty for years after being built, while our roads, bridges, drainage systems, electrical power grid, and other infrastructure deteriorate), but they don't increase productive capacity overall. In other words, they're just redistribution--and almost always (with the COVID relief checks being the only possible exception I can see) from the poor to the rich, since that's who the newly printed money goes to (financial institutions).
> You can clearly see that the limitation on printing money is unutilized resources in the economy.
No, we can clearly see that the limitation on printing money is how much redistribution from the poor to the rich the rich think they can get away with. Remember that the Fed was initially advocated to the US government by rich bankers who were tired of the government coming to them for bailouts whenever there was a financial panic due to stupid government interventions (the Panic of 1907 was the specific one that prompted the legislation that became the Federal Reserve Act), so they decided to put a system in place that would make it so the costs of the bailouts ended up being paid by ordinary citizens (who wouldn't get any of the money the Fed would print) instead of them.