Organic farming releases as much or more "poisons" than conventional. Just because those poisons "natural" doesn't mean they are not harmful. Coppersulfate, pyrethrins, spinosad, neem etc are all indesciminate killers. Rotenone is a banned organic pesticide because it's linked to Parkinson's.

The 3/4 number gets a lot worse when you know we really don't need to farm as much land as we do. If we stopped subsidizing idiotic farming practices and invested heavily in infrastructure, we only need to use 1/4 of the land we do. That includes feeding all the animals. If we migrated to a plant based diet it would be around 1/10th the current land usage.