It's Water-Wise Wednesdays with Frannie the Fish! {TAPS Manual Part 2: Over-Application of Fertilizer}

Frannie's friends at the Groundwater Foundation recently published the second edition of the Training About Protecting the Source (TAPS) Manual. The manual guides users through hands-on activities that explore potential threats to groundwater and challenges them to think about what can be done to protect this key drinking water source.

This manual can be used inside the classroom and is aligned to the national Next Generation Science Standards, but Frannie loves just learning about groundwater, no matter where she is. For the next few weeks, you can join her as she works through the different activities. 

Frannie will be using the Groundwater Foundation's Awesome Aquifer Kit, but if you don't have one, you can follow along with materials that might be found around your home. This is the second part of Frannie's exploration of the TAPS Manual. You can follow the link to see what she learned about improperly abandoned wells.

Today's activity is....Over-Application of Fertilizer.

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Fertilizers promote plant growth and green lawns by helping plants meet their nutrient needs, primarily for nitrogen, phosphorus, and potassium. Plants, however, are limited in the amount they can absorb and use. Fertilizers applied in excess can soak down into the groundwater or run off into surface water bodies. This pollution of surface and groundwater can impact our drinking water supplies.

For this activity, you will need:

• Awesome Aquifer Kit, OR
• Plastic box
• Gravel
• Plastic tube
• Hand pump or Syringe
• Nylon
• Rubber band
• 1 packet or 1 tablespoon of colored powdered drink mix (ex. Kool-Aid, Gatorade, etc)
• 16 oz cup of water

Activity Steps

1. Read through all the instructions first before you begin to build the model. Make sure you have all the needed materials and supplies.

 

2. Fill the plastic box with gravel until it is about ¼ full.

 

3. Add water so that half of the rocks are covered. (This will represent an aquifer.)

 

4. Create a well by covering the end of the plastic tube with nylon, securing it with a rubber band.

 

5. Insert the well, with the well screen on the bottom, near one corner of the plastic box. Push the well down so that it reaches the bottom of the model.

 

6. Add more gravel until the box is about ½-¾ full. The surface of the gravel should be fairly level across the box.

 

7. Sprinkle ½ a packet, about 1 tablespoon, of powdered drink mix (i.e. Kool-Aid) 

on the surface of the gravel to simulate fertilizer.

 

   

8. Pour water on the surface of the gravel to simulate rain.

 

9. Make observations

 

10. Pump the well by inserting the tip of the syringe into the well (plastic tube) or attaching and pumping the hand pump.

 

11. Observe what happens to the fertilizer and water when the well is pumped.

Frannie observed that once the water "rained" over her aquifer, the colored drink mix, which represents fertilizer, quickly mixed with the recharge and infiltrated into the groundwater below. Very quickly, the whole aquifer was contaminated with the red drink mix. When she tried to pump groundwater out, Frannie wasn't able to get any clean water. 

Frannie knows that fertilizers help plants grow healthy and strong, but there are ways and times to apply them responsibly so that plants can absorb all of the nutrients they need without any extra leaching in the groundwater below.