Paddy field

A paddy field (or paddy) is a flooded field of arable land used for growing semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in southern China, associated with pre-Austronesian and Hmong-Mien cultures. It was spread in prehistoric times by the expansion of Austronesian peoples to Island Southeast Asia, Madagascar, Melanesia, Micronesia, and Polynesia. The technology was also acquired by other cultures in mainland Asia for rice farming, spreading to East Asia, Mainland Southeast Asia, and South Asia.

Fields can be built into steep hillsides as terraces or adjacent to depressed or steeply sloped features such as rivers or marshes. They require a great deal of labor and materials to create and need large quantities of water for irrigation. Oxen and water buffalo, adapted for life in wetlands, are important working animals used extensively in paddy field farming.

Paddy field farming remains the dominant form of growing rice in modern times. It is practiced extensively in Bangladesh, Cambodia, China, India, Indonesia, northern Iran, Japan, Laos, Malaysia, Mongolia, Myanmar, Nepal, North Korea, Pakistan, the Philippines, South Korea, Sri Lanka, Taiwan, Thailand, and Vietnam. It has also been introduced elsewhere since the colonial era, notably in northern Italy, the Camargue in France, and in Spain, particularly in the Albufera de València wetlands in the Valencian Community, the Ebro Delta in Catalonia and the Guadalquivir wetlands in Andalusia, as well as along the eastern coast of Brazil, the Artibonite Valley in Haiti, Sacramento Valley in California, and West Lothian in Scotland among other places.^{[citation needed]}

Paddy cultivation should not be confused with cultivation of deepwater rice, which is grown in flooded conditions with water more than 50 cm (20 in) deep for at least a month. Global paddies' emissions account for at least 10% of global methane emissions. Drip irrigation systems have been proposed as a possible environmental and commercial solution.

The word "paddy" is derived from the Malay/Indonesian word padi, meaning "rice plant", which is itself derived from Proto-Austronesian *pajay ("rice in the field", "rice plant"). Cognates include Amis panay; Tagalog pálay; Kadazan Dusun paai; Javanese pari; and Chamorro faʻi, among others. In the original Malay language that English borrows, padi refers to both the rice plant and its unhusked grains, the fields are instead called sawah.

Genetic evidence shows that all forms of paddy rice, including both indica and japonica, spring from a domestication of the wild rice Oryza rufipogon by cultures associated with pre-Austronesian and Hmong-Mien-speakers. This occurred 13,500 to 8,200 years ago south of the Yangtze River in present-day China.

There are two likely centers of domestication for rice as well as the development of the wet-field technology. The first is in the lower Yangtze River, believed to be the homelands of the pre-Austronesians and possibly also the Kra-Dai, and associated with the Kuahuqiao, Hemudu, Majiabang, Songze, Liangzhu, and Maquiao cultures. The second is in the middle Yangtze River, believed to be the homelands of the early Hmong-Mien speakers and associated with the Pengtoushan, Nanmuyuan, Liulinxi, Daxi, Qujialing, and Shijiahe cultures. Both of these regions were heavily populated and had regular trade contacts with each other, as well as with early Austroasiatic speakers to the west, and early Kra-Dai speakers to the south, facilitating the spread of rice cultivation throughout southern China.

The earliest paddy field found dates to 4330 BC, based on carbon dating of grains of rice and soil organic matter found at the Chaodun site in Kunshan. At Caoxieshan, a site of the Neolithic Majiabang culture, archaeologists excavated paddy fields. Some archaeologists claim that Caoxieshan may date to 4000–3000 BC. There is archaeological evidence that unhusked rice was stored for the military and for burial with the deceased from the Neolithic period to the Han dynasty in China.