First you need to gather up all of the materials you will need. Below is a list of the following items needed to conduct this experiment:
• ¼ cup of clay type soil
• 1 pint glass or plastic beaker – 500mL
• 6 volt dry-charge lantern battery
• 2 pieces of 12 gauge, multi-strand copper wire
Are you ready? Let’s get started. Place 60 grams of the soil into the pint glass then add 500 mL of tap water. Stir up the container until the soil is completely mixed with the water then let the mixture settle for at least 10 minutes. Strip the electrical wires on each ends about 2 inches. Attach one end of both of the wires to the terminals on the battery and place the other ends into the soil mixture making sure that the wires are not touching while in the container.
**Make a note as to which wire was connected to the positive end of the battery and which one was attached to the negative end.**
Leave the wires in the mixture for about 10 to 15 minutes and then pull them out to see what happened.
What happened? Which wire do you think would have attracted the clay? As it turns out, the minerals in the clay mixture should have been attracted to the wire attached to the positive end of the battery (the anode) and the plant nutrients should have been attracted to the wire attached to the negative end of the battery (the cathode). We’ve learned here that most plant nutrients bond to clay surfaces and it also confirms that soils are electrical chemical systems that provide potential to attract and hold plant nutrients. The greater the clay concentration in the soil the greater the potential to hold nutrients and make them available to plants.