I do use Epsom salts to increase the magnesium in the soil. The green beans will yellow and shrivel up if I don't. I have black dirt, we call it muck, and it will catch on fire and burn if you aren't careful where you have campfires. This soil needs constant feeding and sometimes I put down lime that has magnesium mixed in with it. These minerals are necessary for our health also. Calcium and magnesium will prevent restless leg syndrome , polyps, heart disease and a host of other nutritional ailments.