As a farmer, the most valuable thing he has is that land. It will be in his family for a long time, so it's in his best interest to protect it. From what he says, it sounds like most of what he does revolves around keeping that resource healthy and productive.
My point is, sometimes you have to realize that what's best for the individual is not what's best for society, and that you need to compromise. (In the case of the school zone, the government mandates that you play nice. You can say hello to a fine if you value your fuel economy over the safety of the children trying to cross the street. In the case of a corn farm, the opposite effect is in play -- the government gives you money to only worry about the health of your land. The planet itself can get bent, it's standing in the way of cheap soda!)
government isnt magic, it is an extension of what people want. a horribly twisted extension, but still an extension.
First, the author makes some good points that without modern tools, some of the things we ask of modern farms would be impossible. There's a limit to the natural productivity of an acre of land.
Second, though, he doesn't address a) whether we're asking too much of one acre of land, or b) whether the things that farmers have to do in order to be productive enough to survive are things that are good to be doing to land, long-term.
The author is essentially saying, "If this is what you ask of me, don't complain about the things I have to do to deliver." And that's a fair point. But let's think more about what we should and shouldn't be asking of him and his land.
Additionally, the author makes a well-argued takedown of some of Michael Pollan's points from The Omnivore's Dilemma, but Joel Salatin — the man whose farming methods are the centerpiece of the book — is conspicuously absent from the critique. Salatin's farm is extremely productive, and sustainably so. That's accomplished by embracing technology (like electric fences that take ten minutes to set up), not by throwing it out and reverting to Depression-era methods.
Salatin's work is more hands-on than that of most farmers, and that's necessary for the type of farm he runs. But it's a model that we'd do well to see spread. (Again, though, it cannot spread widely without some significant changes in what farmers are and are not incentivized to do.)