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Rice

(This article is about the food grain. See also Rice (disambiguation).)


Rice (Oryza sativa) is a plant of the grass family, which provides the bulk of the human diet throughout Asia, i.e. feeds more than half the world's human population. Rice cultivation is well suited to poor countries, as it is very labor-intensive but can be grown practically anywhere plenty of water is available for irrigation, even on steep hillsides. Rice is the world's third largest crop, behind maize and wheat—both of which have significant uses outside of human nutrition.

Rice
Rice field in Southern China
Source: NOAA
Scientific classification
Kingdom:Plantae
Division:Magnoliophyta
Class:Liliopsida
Order:Poales
Family: Poaceae
Genus: Oryza
Species
Oryza barthii
Oryza glaberrima
Oryza latifolia
Oryza longistaminata
Oryza punctata
Oryza rufipogon
Oryza sativa
References
ITIS 41975 2002-09-22
Rice is often grown in paddies--shallow puddles (typically 15cm depth), carefully controlled to ensure the appropriate water depth. Rice paddies sometimes serve a dual agricultural purpose by also producing edible fish or frogs, a useful source of protein. The farmers take advantage of the rice plant's tolerance to water: the water in the paddies prevents weeds from outgrowing the crop. Once the rice has established dominance of the field, the water can be drained in preparation for harvest. Paddies increase productivity, although rice can also be grown on dry land, including on terraced hillsides, often with the help of chemical weed controls.

In some instances, a deepwater strain of rice, often called floating rice is grown. This can develop elongated stems capable of coping with water depths exceeding 2 meters (6 feet).

Rice paddies are an important habitat for birds such as herons and warblers. They perform a useful function in controlling insect pests.

Whether it is grown in paddies or on dry land, rice requires a great amount of water compared to other food crops, making rice growing a controversial practice in some areas, particularly in the United States and Australia, where rice farmers use 7% of the nation's water to generate just 0.02% of GDP.

Draft genomes for the two commonest rice cultivars, indica and japonica, were published in April 2002.

The seeds of the rice plant are first milled to remove the outer husks of the grain; this creates 'brown' rice. This process may be continued, removing all of the husk, creating 'white' rice. The white rice may then be buffed with glucose or talc powder, parboiled, or processed into flour.

The processed rice seeds are usually boiled or steamed to make them edible, after which they may be fried in oil or butter.

Rice varieties are often classified by their grain shapes. For example, Thai or Siamese Jasmine rice is long-grain and relatively less sticky, as long-grain rice contains less starch than short-grain varieties. Chinese restaurants usually serve long-grain as plain unseasoned steamed rice. Japanese rice and Chinese sticky rice are short-grain. Chinese people use sticky rice to make dumplings.

Indian rice varieties include long-grained Basmati (grown in the North), medium-grained Patna and short-grained Masoori. One variety, available in the South Indian state of Kerala, is usually referred to in English as boiled rice. This is prepared by boiling it just after harvesting, in huge pans, often over coconut-shell fires, to kill any fungi or other contaminants. It is then dried, and the husk removed later. It often displays small red speckles, and has a smoky flavour from the fires.

Scientists are working on so-called golden rice which is genetically modified to produce beta carotene, the precursor to vitamin A. This has generated a great deal of controversy over whether the amount of beta carotene would be significant and whether genetically modified foods are desirable.

Specific rice dishes include risotto, paella, sushi, pilaf, and the Indonesian rice table.

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