Rice is a dietary staple of more than half of the world's human population, mostly in Asia. Chinese legend attributes the first cultivation of rice to Shennong, who “invented” agriculture. Whatever the truth of that, it is known that the ancient Egyptians were exporting rice, and large deposits of preserved rice have been found in Roman camps dating to the 1st Century AD. Rice remains vital to stave off famine; world production of rice has risen steadily from about 200 million tons in 1960 to 600 million tons in 2000.