A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such as rivers or marshes. They can require a great deal of labor and materials to create, and need large quantities of water for irrigation. Flooded paddies provide an ideal environment for rice cultivation and discourage the growth of many weeds.[citation needed] The water buffalo is one of the most important working animals adapted for life in wetlands, and is used extensively in paddy field farming.
During the twentieth century, paddy field farming became the dominant form of growing rice.[citation needed] Paddy field farming is practiced in Cambodia, Bangladesh, China, Taiwan, India, Indonesia, Japan, North Korea, South Korea, Malaysia, Myanmar, Nepal, Pakistan, the Philippines, Sri Lanka, Thailand, Vietnam, and Laos, as well as Piedmont in Italy, the Camargue in France, the Artibonite Valley in Haiti, and Sacramento Valley in California. Paddy fields are a major source of atmospheric methane and have been estimated to contribute in the range of 50 to 100 million tonnes of the gas per annum. Recent studies have shown that this can be significantly reduced while also boosting crop yield by draining the paddies to allow the soil to aerate to interrupt methane production.
