Wikimedia Commons / Brad Collis Farmers planting rice in Cambodia

A paddy field is a flooded parcel of arable land used for growing semiaquatic rice. 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. Genetic evidence shows that all forms of paddy rice, both indica and japonica, spring from a domestication of the wild rice Oryza rufipogon that first occurred 8,200–13,500 years ago South of the Yangtze River in present-day China. However, the domesticated indica subspecies currently appears to be a product of the introgression of favorable alleles from japonica at a later date, so that there are possibly several events of cultivation and domestication. Paddy fields are the typical feature of rice farming in east, south and southeast Asia. Fields 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. Oxen and water buffalo, adapted for life in wetlands, are important working animals used extensively in paddy field farming.

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. 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.[7] Studies have also shown the variability in assessment of methane emission using local, regional and global factors and calling for better inventorisation based on micro level data.

India has the largest paddy output in the world and is also the fourth largest exporter of rice in the world. In India, West Bengal is the largest rice producing state. Paddy fields are a common sight throughout India, both in the northern gangetic plains and the southern peninsular plateaus. Paddy is cultivated at least twice a year in most parts of India, the two seasons being known as Rabi and Kharif respectively. The former cultivation is dependent on irrigation, while the latter depends on Monsoon. The paddy cultivation plays a major role in socio-cultural life of rural India. Many festivals such as Onam in Kerala, Bihu in Assam, Makara Sankranthi in Andhra Pradesh and Telangana, Thai Pongal In Tamil Nadu, Makar Sankranti in Karnataka, Nabanna in West Bengal celebrates harvest of Paddy. Kaveri delta region of Thanjavur is historically known as the rice bowl of Tamil Nadu and Kuttanadu is called the rice bowl of Kerala.

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