Consider the case of non-organic crops. They’re fertilized with petrochemicals and pesticides, which kill insects and some of their up-chain predators. And petrochemicals may be dinosaurs, right?
Now consider organic crops. They’re all fertilized with manure. The manure comes from animals which are bred, and usually the males of those breedings aren’t kept around – they go off to make meat goods. Without this outlet, there would be too many aggressive males around and the manure production chain wouldn’t work. Additionally, most organic gardeners still engage in pest control. While all-natural in ingredients or methods, the pesky insects still lose this battle, even if it’s death-by-bird.
Now consider either of these crops being transported by truck or airplane, and there are going to be bird hits and certainly hundreds or thousands of splattered insects on the big-rig windshield on the way across the country.
So, then, we’re left with basically home-grown crops, which are fertilized only with perhaps leaf-mould, which isn’t going to produce very good crops, or wild-bearing crops, like berries, and then there’s not enough to go around, so that’s unsustainable. Unless you fertilize with human waste, which is rarely legal, and, well, eww.
If the point of vegan is to produce food without killing animals – for all practical purposes, nothing is vegan. Life lives on life, marketing lives on hope.