Extreme winter temperatures in the Republic of Korea mean that rice can be planted only once a year. However, high summer rainfall permits average annual production of more than 5 million tonnes. As well as being the country's most important agricultural commodity, rice is also the main source of carbohydrate in people's diets, with annual consumption of around 90 kg per head.
Most rice varieties planted belong to modern japonica sub-species. It is estimated that 79 percent of the harvested rice area is under irrigation, while 20 percent is rainfed lowlands. Except for the south-western part of the country, most rice fields lie in valleys between mountains with steep slopes. The planting season is in May-June, and harvesting takes place in October-November. Mechanical transplanting is the main method of crop establishment.
Rice culture in the Republic of Korea is distinct from that of other countries. Land ownership limitations means that agriculture is structured around small-scale farmers, who earn almost half of their income from rice. The country now produces a rice surplus, and per capita consumption has fallen from 128 kg in 1985 to 83 kg in 2003. Farmers are concentrating on quality to maintain the domestic consumption level and do not rely on export markets.
One of the important fermentation products made from rice in Korea is Makkulli, or rice wine. It is made using Nuruk, a powdered fermentation mix derived from barley, and contains less than 8% alcohol.