If a fraction of that money went towards research of alternative agricultural practices, we wouldn’t have to worry about how to produce more nitrogen while simultaneously dealing with the detrimental effects of nitrogen pollution, as we are currently
Would be an even better comparison if we account for the externalities, like soil erosion and ecocide from pesticide/fertilizer run-off.
Externalities are a /way/ larger issue than just monoculture or even modern pesticides and fertilizer though.
When was the last famine in the United States? When was the last famine anywhere on the planet that wasn't due to some kind of fucked-up government?
Drawing down savings to pay the mortgage works just fine too, until they run out. There being no obvious alternatives doesn't mean you won't end up homeless.
Poly cropping almost certainly ends up being more labor intensive, and even requiring some knowledge on the ground. The trend is very much so improving profit by reducing labor.