3rd Grade - Science

LESSON PROBLEM: Biology: What have rice farmers done to get more rice from the land they farm?


Rice grows on fields flooded with water. It would seem that growing rice must use a lot of water. But this is not true. In fact, rice is one of the most water efficient sources of nutrition we eat. To grow one serving of beef takes 1,231 gallons of water. Canteloupe takes about 40 gallons and chicken 330 gallons. While rice takes only 25 gallons! Rice farmers in the United States are the most efficient in the world. Rice farming also makes the water it uses cleaner. And, a field of rice helps clean the air we breathe.

The United States rice industry has developed special rice plants. They are the dwarf rice plants. Dwarf means small in size. The smaller plant grows using less water. The dwarf rice plant is not as tall as other rice plants, but it produces a lot of rice.

U.S. rice farmers are very careful to make sure that their rice fields are carefully leveled. When fields are evenly leveled and look like your tabletop, they need less water to grow the rice. Fields that are uneven need more water to fill the dips and holes in the fields.

The rice fields also "clean" the water on the fields. Sunlight and time break down chemicals that might be in the water. When the water is returned to the environment, it is cleaner than before it was put onto the rice field.

Another way farmers save water is to reuse it. When the water is drained from the rice field it is saved to be used another time. They very carefully measure the depth of the water in the rice field to keep it at an exact level.

The clay soil found in the rice belts of Arkansas, California, Louisiana, Mississippi, Missouri and Texas are perfect for growing rice. It holds the water so it is not lost from seeping. Rice farmers prefer to plant rice in clay soil.

Because rice is a green plant, it pumps oxygen into the air. It cleans the air of another gas called carbon dioxide. This is called photosynthesis. During photosynthesis the air is cleaned. In one year, an acre of rice can clean the air of the pollution from one automobile. Rice farming in Sacramento Valley, California, pumps enough oxygen into the air each year for the entire city of Los Angeles.

Rice farming helps everyone. It provides a nutritious food, cleaner water and cleaner air.


1. Materials needed are clay, 2 glasses and water.

2. Put the clay into two equal parts. Put each part into a glass.

3. In one glass, firmly press the clay. Make it even and level.

4. In the other glass, firmly press the clay. Make it uneven and not level.

5. Fill two small cups of water. Carefully pour the water into each glass.

6. Measure the level of water in each glass.

7. Which glass has the least water? Explain your answer.


Draw a picture that shows how photosynthesis happens. Label your picture.


  • dwarf
  • California
  • acre
  • photosynthesis
  • pollution
  • oxygen
  • carbon dioxide
  • scrub

Click here to play Rice Rampage!
The Milling Process for Rice:
Getting rice from the field to you takes
a few more steps. Click here to see a video & learn more about the rice milling process.
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