6th Grade - Social Studies

LESSON PROBLEM: Geography: Why does California have a higher rice yield than the other rice producing states?


The United States is a highly industrialized country in which the majority of people are employed in the manufacturing and service sectors. Only 1.8% of the population work in farming. In 1992 there were 2.1 million farms in the U.S., the average size of which was 189 hectares. Rice production accounts for no more than 1% of U.S. agricultural output. Even so, U.S. rice makes up about 14% of global rice exports.

The United States consistently has the highest yields of rice in the world, using modern, efficient methods that conserve water, maximize output, reduce erosion and provides important wetlands habitat for migrating waterfowl. U.S. rice is produced in the Grand Prairie of Arkansas; the Mississippi River delta of Mississippi, Arkansas, Louisiana and Missouri; the Gulf Coast of Louisiana and Texas; and California's Sacramento Valley. Unlike the others, which are moist subtropical climates, the climate in the Sacramento Valley is semiarid, which means that it is much drier.

Rice is an annual crop that is harvested once a year. All U.S. rice crops are irrigated and seeded directly into the ground (rather than transplanted as seedlings). The rice is either seeded directly into the soil of dry fields using a mechanical grain drill, or pregerminated seed is dropped by airplane into flooded fields.

U.S. rice is grown on natural flatlands. Much of these are further precision-leveled by laser directed machines. Such precise leveling maximizes efficiency of water management and therefore, rice yields.

California yields tend to be higher for a variety of reasons. California grows primarily medium grain rice which yields more grain per hectare. California is located at a higher latitude which provides for stronger solar radiation on the land. The dry climate also gives less opportunity for plant disease to thrive. The average rice yield in California is 9.4 tons/hectare. In the humid southern rice farms, diseases like blast and blight, are more of a problem. This compounded with a greater number of cloudy days and storms during the growing season, limits average yields to about 6.5 tons/hectare. But both U.S. rice growing areas yield more rice than other rice growing countries. The average world rice yield is only about 3.9 metric tons per acre or 3,500 pounds per acre (the average U.S. yield is 6,200 pounds per acre).

Current and future challenges for rice farmers will center around increasing yield while maintaining high quality and sustaining the natural environment.


Describe the ideal rice growing environment.


Find out more about U.S. rice farming and its effects on the environment. What are some positive impacts rice farming has on the environment?
What are some negative effects?

  • yield
  • semiarid
  • laser
  • blight
  • thrive
  • subtropical
  • delta

Click here to play Rice Rampage!
Baldo is actually a type of specialty rice grown right here in the U.S. Other types include basmati, jasmine and arborio.
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