World production and trade

Rice cultivation began in California during the California Gold Rush, when an estimated 40,000 Chinese laborers immigrated to the state and grew small amounts of the grain for their own consumption. However, commercial production began only in 1912 in the town of Richvale in Butte County. By 2006, California produced the second largest rice crop in the United States, after Arkansas, with production concentrated in six counties north of Sacramento. Unlike the Mississippi Delta region, California's production is dominated by short- and medium-grain japonica varieties, including cultivars developed for the local climate such as Calrose, which makes up as much as eighty five percent of the state's crop. References to wild rice in the Americas are to the unrelated Zizania palustris

More than 100 varieties of rice are commercially produced primarily in six states (Arkansas, Texas, Louisiana, Mississippi, Missouri, and California) in the U.S. According to estimates for the 2006 crop year, rice production in the U.S. is valued at $1.88 billion, approximately half of which is expected to be exported. The U.S. provides about 12% of world rice trade. The majority of domestic utilization of U.S. rice is direct food use (58%), while 16 percent is used in processed foods and beer respectively. The remaining 10 percent is found in pet food. Although attempts to grow rice in the well-watered north of Australia have been made for many years, they have consistently failed because of inherent iron and manganese toxicities in the soils and destruction by pests.