Paddy field
A paddy field 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 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 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, 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.
Paddy cultivation should not be confused with cultivation of deepwater rice, which is grown in flooded conditions with water more than 50 cm deep for at least a month. Global paddy emissions account for at least 10% of global methane emissions. Drip irrigation systems have been proposed as a possible environmental and commercial solution.
Etymology
The word "paddy" is derived from the Malay word padi, meaning "rice plant", which is itself derived from Proto-Austronesian *pajay. Cognates include Amis panay; Tagalog pálay; Kadazan Dusun paai; Javanese pari; and Chamorro fai, 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.History
Neolithic southern China
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 Maqiao 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.
By the late Neolithic, population in the rice cultivating centers had increased rapidly, centered around the Qujialing-Shijiahe and Liangzhu cultures. There was evidence of intensive rice cultivation in paddy fields as well as increasingly sophisticated material cultures in these two regions. The number of settlements among the Yangtze cultures and their sizes increased, leading some archeologists to characterize them as true states, with clearly advanced socio-political structures. However, it is unknown if they had centralized control.
In the terminal Neolithic, Shijiahe shrank in size, and Liangzhu disappeared altogether. This is largely believed to be the result of the southward expansion of the early Sino-Tibetan Longshan culture. Fortifications like walls are common features in settlements during this period, indicating widespread conflict. This period coincides with the southward movement of rice-farming cultures to the Lingnan and Fujian regions, as well as the southward migrations of the Austronesian, Kra-Dai, and Austroasiatic-speaking peoples to Mainland Southeast Asia and Island Southeast Asia.
Austronesian expansion
The spread of japonica rice cultivation and paddy field agriculture to Southeast Asia started with the migrations of the Austronesian Dapenkeng culture into Taiwan between 3500 and 2000 BC. The Nanguanli site in Taiwan, dated to ca. 2800 BC, has yielded numerous carbonized remains of both rice and millet in waterlogged conditions, indicating intensive wetland rice cultivation and dryland millet cultivation.File:KITLV 40091 - Kassian Céphas - Relief of the hidden base of Borobudur - 1890-1891.jpg|thumb|right|Bas-relief of Karmawibhanga of 9th century Borobudur describe rice barn and rice plants being infested by mouse pestilence. Rice farming has a long history in Indonesia.
From about 2000 to 1500 BC, the Austronesian expansion began, with settlers from Taiwan moving south to migrate to Luzon in the Philippines, bringing rice cultivation technologies with them. From Luzon, Austronesians rapidly colonized the rest of Maritime Southeast Asia, moving westwards to Borneo, the Malay Peninsula and Sumatra; and southwards to Sulawesi and Java. By 500 BC, there is evidence of intensive wetland rice agriculture already established in Java and Bali, especially near very fertile volcanic islands.
Rice did not survive the Austronesian voyages into Micronesia and Polynesia; however, wet-field agriculture was transferred to the cultivation of other crops, most notably for taro cultivation. The Austronesian Lapita culture came into contact with the non-Austronesian early agriculturists of New Guinea and introduced wetland farming techniques to them. In turn, they assimilated their range of indigenous cultivated fruits and tubers before spreading further eastward to Island Melanesia and Polynesia. In Hawaii, the conditions of available taro pondfields as worked by native Hawaiians later proved feasible for rice cultivation by Chinese and Japanese migrant farmers in the late 19th to early 20th century; rice plots were often enlarged by dismantling bunds that bordered between smaller established loʻi.
Rice and wet-field agriculture were introduced to Madagascar, the Comoros, and the coast of East Africa around the 1st millennium AD by Austronesian settlers from the Greater Sunda Islands.
Korea
There are ten archaeologically excavated rice paddy fields in Korea. The two oldest are the Okhyun and Yaumdong sites, found in Ulsan, dating to the early Mumun pottery period.Paddy field farming goes back thousands of years in Korea. A pit-house at the Daecheon-ni site yielded carbonized rice grains and radiocarbon dates, indicating that rice cultivation in dry-fields may have begun as early as the Middle Jeulmun pottery period in the Korean Peninsula. Ancient paddy fields have been carefully unearthed in Korea by institutes such as Kyungnam University Museum of Masan. They excavated paddy field features at the Geumcheon-ni Site near Miryang, South Gyeongsang Province. The paddy field feature was found next to a pit-house that is dated to the latter part of the Early Mumun pottery period. KUM has conducted excavations, that have revealed similarly dated paddy field features, at Yaeum-dong and Okhyeon, in modern-day Ulsan.
The earliest Mumun features were usually located in low-lying narrow gullies, that were naturally swampy and fed by the local stream system. Some Mumun paddy fields in flat areas were made of a series of squares and rectangles, separated by bunds approximately 10 cm in height, while terraced paddy fields consisted of long irregular shapes that followed natural contours of the land at various levels.
Mumun Period rice farmers used all of the elements that are present in today's paddy fields, such as terracing, bunds, canals, and small reservoirs. We can grasp some paddy-field farming techniques of the Middle Mumun, from the well-preserved wooden tools excavated from archaeological rice fields at the Majeon-ni Site. However, iron tools for paddy-field farming were not introduced until sometime after 200 BC. The spatial scale of paddy-fields increased, with the regular use of iron tools, in the Three Kingdoms of Korea Period.
Japan
The first paddy fields in Japan date to the Early Yayoi period. The Early Yayoi has been re-dated, and based on studies of early Japanese paddy formations in Kyushu it appears that wet-field rice agriculture in Japan was directly adopted from the Lower Yangtze river basin in Eastern China.Culture
China
Although China's agricultural output is the largest in the world, only about 15% of its total land area can be cultivated. About 75% of the cultivated area is used for food crops. Rice is China's most important crop, raised on about 25% of the cultivated area. Most rice is grown south of the Huai River, in the Yangtze valley, the Zhu Jiang delta, and in Yunnan, Guizhou, and Sichuan provinces.Rice appears to have been used by the Early Neolithic populations of Lijiacun and Yunchanyan in China. Evidence of possible rice cultivation from ca. 11,500 BC has been found, however it is still questioned whether the rice was indeed being cultivated, or instead being gathered as wild rice. Bruce Smith, an archaeologist at the Smithsonian Institution in Washington, D.C., who has written on the origins of agriculture, says that evidence has been mounting that the Yangtze was probably the site of the earliest rice cultivation. In 1998, Crawford & Shen reported that the earliest of 14 AMS or radiocarbon dates on rice from at least nine Early to Middle Neolithic sites is no older than 7000 BC, that rice from the Hemudu and Luojiajiao sites indicates that rice domestication likely began before 5000 BC, but that most sites in China from which rice remains have been recovered are younger than 5000 BC.
During the Spring and Autumn period, two revolutionary improvements in farming technology took place. One was the use of cast iron tools and beasts of burden to pull plows, and the other was the large-scale harnessing of rivers and development of water conservation projects. Sunshu Ao of the 6th century BC and Ximen Bao of the 5th century BC are two of the earliest hydraulic engineers from China, and their works were focused upon improving irrigation systems. These developments were widely spread during the ensuing Warring States period, culminating in the enormous Du Jiang Yan Irrigation System engineered by Li Bing by 256 BC for the State of Qin in ancient Sichuan. During the Eastern Jin and the Northern and Southern Dynasties, land-use became more intensive and efficient, rice was grown twice a year and cattle began to be used for plowing and fertilization.
By about 750, 75% of China's population lived north of the Yangtze, but by 1250, 75% of China's population lived south of it. Such large-scale internal migration was possible due to introduction of quick-ripening strains of rice from Vietnam suitable for multi-cropping.
Famous rice paddies in China include the Longsheng Rice Terraces and the fields of Yuanyang County, Yunnan.