One winter I sat in Army fatigues somewhere near Anniston, Alabama, eating my supper out of a mess kit. The infantry training battalion that I had been assigned to was on bivouac. There was a cold drizzle of rain, and everything was mud. The sun had gone down.

I was still hungry when I finished and noticed that a man nearby had something left over that he was not going to eat. It was a turnip, and when I asked him if I …