That's my new slogan to describe how a vegan amends agricultural soil, so as to end up with green plants that have good nutritional value for humans. When cultivating animals for food, what one feeds the animals is important for making the animals palatable and nutritious for humans; the same goes for cultivating plants. Plant nutrition, general animal nutrition, human nutrition, as well as proper disposal of the waste products and dead bodies of plants, animals in general, and humans, are all part of making sure humans are well cared for. Feeding yourself well, requires feeding your food well. If you are a vegan, that means feeding agricultural plants well, and good stewardship of uncultivated land.
But what is well? Is it simply, as most people seem to think, maximum yield balanced with minimum damage to the environment. Or is there more involved? There is more involved. Just because a plant grows large, and looks good and tastes good, doesn't necessarily mean it has a nutrient constitution, of those nutrients needed by humans, that is ideal.
For example plants don't need iodine to grow well, but humans do. Historically we have gotten iodine from plants. But if the soil they are grown in is low in iodine, the plants will grow just the same as if it has more desirable levels, from a human nutrition standpoint, of iodine. Just imagine commercial farmers thoughts about iodine, whether they are organic farmers or industrialized-west farmers. I doubt they give much thought to it. It doesn't affect yield, or marketability. But it does affect human health.
Feeding green plants doesn't require making sure their soil has iodine. Feeding our food does require making sure their soil has iodine.
The most obvious way of making this happen is to cultivate your food yourself. Simpler than making laws forcing farmers to add iodine to the soil. Simpler than taking sources of iodine produced in pill factories.