I am not sure if that above is linked to your Bulk of land comment - it doesnt make sense if it is - so I will answer this separately.<quoted text>
So they use weedkillers and fertilizers and every other means to curtail weeds and thorns and maximize the yield of corn and crops.
This is a general statement, which every one should have understood.
How a genius like you missed it?
As you should know, there are a variety of cropping systems. Till vs No Till, organic vs conventional, monoculture vs polycutlure, vs cover crop monoculture, GMO vs nonGMO, etc etc...as well as a variety of weeding techniques
All of these have different ramifications the generation of weeds, and the strategies to address them
Speaking in generalities is useless, and makes me wonder if you know anything about farming other than the tiny bit of experience from your poverty stricken origins.