It was Liebig, you’ll recall, who thought he had found the chemical key to soil fertility with the discovery of NPK, and it was the same Liebig who thought he had found the key to human nutrition when he identified the macronutrients in food. Liebig wasn’t wrong on either count, yet in both instances he made the fatal mistake of thinking that what we knew about nourishing plants and people was all we needed to know to keep them healthy. It’s a mistake we’ll probably keep repeating until we develop a deeper respect for the complexity of food and soil and, perhaps, the links between the two.
