Couple of issues here, based on previous post and postulations.
Artificial fertilizers are neither sustainable nor practical once oil reserves are depleted. When they go, mega farming is going to have a lot of new challenges. We are going to have to unwind a lot of politcal decisions made here in the USA at least, and likely worldwide. For instance, the USA cold-war farm boom led to excessive grains being produced, which lead to:
1) Farm support payments
2) Government food charts recommending massive grain consumption (remember the food pyramid?)
3) USDA certified meats being graded by how much white fat was contained, the more the better... fat that only comes from feeding cattle corn (grass fed cattle have yellow fat due to their content of fat soluable vitamins).
4) Dependancy on selling excess grain overseas (violates the local food principle)
Note we have the technology to solve many of the worlds food problems... and can do it improving local practices in sustainable ways. For instance, many societies depend on sweet potatoes for their primary calories. However, the varieties grown are subject to a fungus that reduces yields by 90%. I'm under the impression GMO technology could solve (has already solved?) that problem, but local governments refused to allow GMO into their countries - they rather have their populations starving and easier to control.
Personally, I think the government need to encourage at least 10% of the population to be involved with farming. Below that level and the general population losses touch with food reality... like the woman that posted in a newspaper: "Hunters should be ashamed of themselves, they should buy their meat at the grocery store like everyone else - where no animals are harmed."