Rice, the cereal that serves as the staple for a third of the world’s population, is a unique crop given its habit of being semi-aquatic. Rice (Oryza sativa ) is native to tropical and subtropical areas of south & southeast Asia. Globally rice provides more than one fifth of the calories required by humans.
It is one of the earliest crops domesticated by the human race and is an ancient crop which has mention in the Rig Veda and other ancient Indian literature. The Kashyapiyakrishisukti by Kashyapa is the most detailed ancient Sanskrit text on rice cultivation. It is believed that Chinese started to eat rice about 5,000 years ago. It is also believed that rice cultivation was originated by Shen Nung, the Divine Farmer, around 2,737 BC. Rice has been cultivated for thousands of years in Asia. Grains of rice discovered at an excavation in South Korea in 2003 proved to be the earliest known domesticated rice: carbon dating showed the grains to be around 15,000 years old – 3,000 years earlier than the previously accepted date for the origin of rice cultivation in China around 12,000 years ago.
Rice takes 100–200 days to mature in warm, wet conditions. During its growing period, it needs to be flooded either by the heavy monsoon rains or by irrigation. This restricts the cultivation of swamp rice, the usual kind, to level land and terraces. Outside Asia, centers of rice production include the Po Valley in Italy, and Louisiana, the Carolinas, and California in the USA.
Rice is an extremely healthy food for a number of reasons. Rice is a complex carbohydrate, which means that it contains starch and fiber. Complex carbohydrates are digested slowly, allowing the body to utilize the energy released over a longer period which is nutritionally efficient. Rice has low sodium content and contains useful quantities of potassium, the B vitamins, thiamin and niacin. Rice is a source of magnesium, thiamin, niacin, phosphorus, vitamin B6, zinc and copper. Some varieties have iron, potassium and folic acid. Rice is also gluten free, so suitable for coeliacs, as it is easily digested, and therefore a wonderful food for the very young and elderly. Rice is suitable for vegetarians and vegans, with brown rice in particular complementing vegetarian and vegan dishes.