Traditional method of cutting paddy plants with sickle.. Rice is a cereal grain that comes from the Oryza sativa plant, a member of the grass family. The cooked seeds of this plant account for over three-quarters of the total calorie intake for residents of Asian countries such as India, Japan, China and Indonesia; half of the world's population depends on rice as their major food source. Machines and tools used in rice cultivation are a combination of traditional hand implements and mechanic