Salinity Activity

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Salt in action experiment:- Go to the Adelaide University Soil Science web site and read about how salt is concentrated at the surface of soil by evaporation.

In this experiment you will see this process in action. You will also see the effect of salt on the growth of seedlings.

You will need:

• 2 cups of water
• Salt
• Teaspoon
• Paper towels
• Wheat or other easy to grow seeds
• 2 saucers
• Paper for labelling cups and saucers

What to do:

1. Fill each cup with clean tap water.

2. Label one cup "tap water".

3. Add 3 teaspoons of salt to the other cup and stir until all the salt has dissolved. Label this cup "salty water".

4. Place a paper towel in each cup so that the towel is half in and half out of the water.

5. Leave the cups and paper towels on a window ledge or other warm place for a few days. Water will travel up the paper towels, evaporate, and concentrate the salt at the top.

6. Remove the paper towels from their cups. Cut off the bottom of each paper towel (the part that was in the water). You will now use the top part of the towel only.

7. Taste a small bit of the top of each paper towel to see whether salt travelled up the paper towel dipped in salty water.

8. Place each paper towel in a saucer.

9. Place 10 wheat seeds on each paper towel. Label the saucers as "salty " or "unsalty".

10. Keep seeds moistened with tap water (pretend this is rain).

11. Record the number of seeds germinating in each saucer over a two week period.

12. The salt concentrated at the top of the paper towel by evaporation in the "salty" treatment, should interfere with germination of your seeds. If this did not happen, think of some reasons why it didn't.