I am sure they are sustainable. But the problem is the scale of food production needed to feed the number of people that exist. You and I can eat all organic, we can grow and buy all the organic food we like but all people on earth cannot do the same due to a lack of nitrogen and other limitations. A farm can be sustainable but 7 billion people cannot be sustained without artificially derived nitrogen.
I am sure they are sustainable. But the problem is the scale of food production needed to feed the number of people that exist. You and I can eat all organic, we can grow and buy all the organic food we like but all people on earth cannot do the same due to a lack of nitrogen and other limitations. A farm can be sustainable but 7 billion people cannot be sustained without artificially derived nitrogen.