Rice

Rice is grown across an unusually wide range of ecosystems compared with most other cereals, from permanently flooded lowland paddies to entirely rain-fed upland fields. This flexibility has allowed it to become a staple across many different climates and landscapes.

Production ranges from small, labor-intensive family farms to large mechanized operations. Because growing conditions and cultivation systems differ so widely, agronomic details such as establishment method, water management, and variety choice are highly region-specific.

Family

Poaceae (grass family)

Genus and species

Oryza sativa

Major subspecies groups

Indica and japonica, distinguished by grain morphology, cooking quality, and regional adaptation

Growth habit

Semi-aquatic annual grass tolerant of flooded soil conditions, though upland types are grown without flooding

Rice was domesticated in Asia, with the Yangtze River region commonly cited as a key area of early cultivation, and spread throughout South and Southeast Asia over subsequent millennia. It later reached Africa, the Middle East, and, following European contact, the Americas.

Rice is now grown on every inhabited continent, with the largest production concentrated in Asia. Current data on planted area, production, and trade by country are compiled by FAO and national statistical agencies and should be drawn from those primary sources.

Rice is generally a warm-climate crop that grows best with consistently warm temperatures and, in most production systems, high humidity or standing water. It is sensitive to cold temperatures, particularly around flowering, when cool spells can reduce grain set.

Day length and temperature also influence flowering time in many varieties, and variety choice is matched to the length of the local growing season and the target planting window.

Lowland rice is typically grown on fine-textured soils with low permeability, which help maintain standing water in bunded fields. Upland rice, by contrast, is grown on well-drained soils without flooding, more similar to other rain-fed cereals.

Rice is established either by transplanting seedlings raised in a nursery bed or by direct seeding into the field, with the choice depending on labor availability, water control, and local practice. It is grown across several broad ecosystems that differ mainly in water source and management.

Rotation with other crops, such as wheat or legumes, is practiced in some regions and can help manage weeds, pests, and soil fertility between rice seasons.

Nitrogen strongly influences rice yield and is typically the nutrient managed most intensively, while phosphorus, potassium, and, in some soils, zinc support establishment and grain fill. Nutrient availability is also affected by flooding, which changes soil chemistry relative to non-flooded systems.

Water management is a central part of rice production. In irrigated and rainfed lowland systems, fields are typically kept flooded for much of the growing season, while upland rice relies entirely on rainfall like other rain-fed crops.

Water requirements and irrigation scheduling methods for flooded rice differ from those used for non-flooded crops; reference guidance is published by FAO and national agricultural and irrigation agencies.

Rice is affected by diseases such as rice blast, sheath blight, and bacterial leaf blight, whose importance varies by region, variety, and water management. Insect pests, including aphids, planthoppers, and stem borers, can reduce yield directly or transmit viruses.

Management typically combines resistant varieties, water and nutrient management, field monitoring, and, where warranted, locally authorized control measures used according to their labels.

Rice is harvested once grains have matured and dried to a moisture content suitable for threshing and safe storage. Fields are typically drained ahead of harvest to allow access for manual or mechanical harvesting equipment.

• Milled and parboiled grain for direct human consumption as a staple food
• Rice flour and starch used in a range of food products
• Rice bran and broken grain used in animal feed
• Straw and husk used for livestock bedding, fuel, or as a soil amendment in some regions