The exact origin of rice will perhaps never be known. However, it is certain that the domestication of rice ranks as one of the most important developments in history. It has fed more people over a longer period than has any other crop.
Linguistic evidence suggests the early origin of cultivated rice in the Asian arc. In several Asian languages, the general terms for rice and food, or for rice and agriculture, are synonymous.
Recurrent references are made to rice in both Hindu and Buddhist scriptures. In both the religions, rice is used as a major offering to the gods. This proves the longevity of rice as a staple item of the diet.
Archeologists have found evidence that rice was an important food in Mohenjo-Daro as early as 2500 B.C. and in the Yangtze Basin in the late Neolithic period (Chang 1967a). Rice and related farming implements dating back at least 8,000 years were found there and rice cultivation seems to have spread down the rivers over the following 2,000 years.
Pottery shards bearing the imprint of both grains and husks of rice were discovered at the Korat area of Thailand. This is the earliest and most convincing archeological evidence for domestication of rice. These remains date back to at least 4000 B.C.
This evidence not only pushes back the documented origin of cultivated rice but, when viewed in conjunction with plant remains from 10,000 B.C. discovered in Spirit Cave on the Thailand-Myanmar border, suggests that agriculture itself may be older than was previously thought.
Perhaps from diverse beginnings in different parts of Asia, the process of diffusion has carried rice in all directions and today it is cultivated on every continent except Antarctica. Thousands of rice varieties are grown in more than 100 countries.
According to folklore in Burma, Bali, India and Japan, rice is considered to be a Gift of the Gods. Rice is treated with reverence, and its cultivation is tied to elaborate rituals.
Rice is an annual plant that is harvested once a year. The cultivation of rice is suited for countries with low labor costs and high rainfall as it is very labor intensive and requires large amounts of water for cultivation.
Methods of growing differ greatly in different localities, but in most Asian countries the traditional hand methods of cultivating and harvesting rice are still practiced.
The fields are prepared by
a) Plowing (typically with simple plows drawn by water buffalo)
b) Fertilizing (usually with dung or sewage) and
c) Smoothing (by dragging a log over them)
The seedlings are started in seedling beds and, after 30 to 50 days, are transplanted by hand to the fields, which have been flooded by rain or river water.
During the growing season, irrigation is maintained by dike-controlled canals or by hand watering.
The fields are allowed to drain before cutting.
Rice when it is still covered by the brown hull is known as paddy; rice fields are also called paddy fields or rice paddies. Rice is threshed to loosen the hulls—mainly by flailing, treading, or working in a mortar—and winnowed free of chaff by tossing it in the air above a sheet or mat.