While unsure of what's causing the depleted nutrients, one theory is that the more grains or beans a plant produces, the more diluted the nutrients become. (insteading.com)
Zenimura noticed that castor bean plants thrived in the desert. (si.com)
According to Mike Grusak, a research plant physiologist with the USDA - ARS and a professor at Baylor College of Medicine, «besides the protein, fiber, and minerals in the seeds, the leaves of bean plants are also edible. (sciencedaily.com)