A rice crop is a type of cereal grain intentionally grown and harvested for human consumption. The growth of rice crops is one of the oldest known forms of agriculture, thought to date back to around 8000 BCE. Depending on the availability of water, rice crops may be wet-cultivated or dry-grown. Despite being a major food staple for much of the word, the growth, harvest, and processing of a rice crop remains a complicated process, both labor and resource intensive.
For thousands of years, Oryza sativa, or Asian rice, grew wild throughout much of the Asian subcontinent. Historians estimate that, while wild-grown rice was a major part of the Asian diet for thousands of years, it did not become a widely cultivated crop until somewhere between 8000-6000 BCE, though some studies have suggested a far earlier date. In Africa, a related grain, known as Oryza glabberrima, also became a cultivated crop around 1,000 BCE. As a domesticated crop, rice quickly became a central staple grain for cultures around the world, a tradition that continues in the modern era.
The life cycle of a rice crop includes several important steps, namely cultivation, harvesting, and processing. In irrigated areas or on flood plains, the rice field is flooded with shallow water, then rice seedlings are planted, either by hand or spread by small, low-flying airplanes. In areas with less water, rice may be simply planted in dry ground, much like other cereal grain crops. The maturation of a rice crop takes four or five months, depending on the climate and growing method.
The harvest of a rice crop is often a difficult process, as the rice grains are quite delicate. In wet-cultivated paddies, the fields must be drained before harvesting can begin. Rice may be harvested by hand, but is often done by machine in larger fields, using specialized equipment that can separate the grains from the stalk without harming the rice. The yield of a harvest may vary throughout the year; in wet-grown rice, yields are often best during rainy periods of the year.
Once harvested, a rice crop must be processed for human use. Most rice goes through an initial milling process in which the husk is removed from the grain. Rice without the husk is known as brown rice, since it retains the tan-colored bran layer. Brown rice may be milled again, removing the bran and leaving only the central, milk-colored grain known as white rice. Both brown and white rice may go through further processing to create syrup, oil, or powder.
The uses of a rice crop are nearly endless. As a food, white or brown rice may be sold as is, turned into cereal, or processed into rice flour or rice syrup. Rice can be processed into a starchy powder that may be used in cosmetics as a stabilizing agent. Even the discarded husk of the rice grains can be used in the creation of biofuels, and as a component in paper and insulation materials.