Chemicals kill weeds and grass, fertilizer is phosphorus n potassium, sulfur and nitrogen, those are key for growing corn. Most use round up, which u could drink if u wanted to. We take care of the land, if we don't yields go down and u don't make money
Many fertilizers are inorganic/chemical based though. You're not suggesting that commercial fertilizers are just as safe for the environment/soil health than organic composts/manures/fertilizers, yes? What about trace mineral depletion through the continued use of commercial fertilizers? Commercial fertilizers don't "put back" everything that plants take out. Organics (compost/manure) does.
Addressing your Roundup...Drink it? Umm...no thanks. I was once an avid user of Roundup until a few things occurred. First, Monsanto forcing farmers to use their GMO "Roundup Ready" seed and getting patents on their seed (in the old days universities released strains to the public domain....for free). Secondly, a study in Argentina that has been successfully quelled linking Roundup to some pretty severe birth defects...
Monsanto's herbicide Roundup linked to birth defects in Argentina's agricultural areas?
Monsanto has done well at covering this up and dismissing it, but all things being equal, I distrust a corporation who has dep pockets and is entrenched in government (USDA and FDA) and contributes heavily to lawmakers in return for legislative favors.
You can drink your Roundup, but hopefully you've already had your children.