> You can't just grow plants without fertilizer.

Not going to go into the meat vs plant nutrients debate in which I probably don't have enough knowledge to chime in.
But you can grow plants without (synthetic) fertilizer. And it's not about organic farming or whatever, it's just about basic plant biology and requirements. Otherwise how would there be plants anywhere? Plants are over 80% of the world's biomass.

You can't grow plants without fertilizer using current high input intensive agriculture, since there's just enough going on in the ground to properly turn organic matter into usable nutrients by the plants. They just can't do that by themselves. So either you provide them with readily available nutrients through fertilizing, or you help the soil's life do it's freaking job and feed it enough dead stuff so it provides plants with usable nutrients.
But that requires no till farming, green manure crop, and so on to avoid growing on a dead soil and thus being dependent on synthetic fertilizers. And not everyone has the time to do that.

I was thinking : damn that documentary production must have been huge, then realized the farmer is also the filmmaker.