Materials Required:
3 identical plastic bottles (with bottoms cut off)
3 additional plastic bottles (with tops cut off)
Ground soil
Dead vegetal waste (twigs, bark, leaves, dead roots)
Seeds (e.g., watercress, basil, chives)
Plastic cutouts from bottles (for greenhouse effect)
String
Hot glue and plywood tablet
Water
Sunlight exposure area
Notebook and pencil for recording observations
Steps Involved:
Prepare Bottles:
Cut the bottoms off three identical plastic bottles. Secure these bottles onto a flat surface using hot glue on a plywood tablet. Ensure the openings of the bottles protrude slightly from the surface.
Cut the bottoms off three additional plastic bottles and make two holes for string. These will serve as cups to collect excess water during the experiment.
Fill Bottles:
In the first bottle, add and press down the ground soil to pack it tightly. This bottle will be used to plant seeds.
In the second bottle, add dead vegetal waste (twigs, bark, leaves, dead roots) on top of the soil.
Leave the third bottle filled only with ground soil.
Plant Seeds:
Spread seeds (watercress, basil, and chives) evenly in the first bottle. Cover the seeds with a layer of soil and press down slightly.
Use the cut plastic piece from the bottle as a cover to create a mini greenhouse effect, which helps seeds germinate faster.
Water and Expose:
Water the soil in all three bottles. Place the first bottle with seeds in a sunny area to promote plant growth.
Ensure the other two bottles are also in a similar light environment for consistency.
Monitor and Record:
Regularly observe the growth of plants in the first bottle and note their development.
Check the second and third bottles for water clarity. Water should progressively become dirtier in these bottles due to the lack of vegetation.
Collect and Analyze Water:
After the plants in the first bottle have developed, collect the water from each bottle and observe its clarity. Compare the water from the bottle with plants to the water from the bottles with only soil and vegetal waste.
Discuss Results:
Discuss with students how the presence of plants helped keep the soil in place and led to clearer water, while the lack of vegetation resulted in more soil erosion and dirtier water.
Relate these observations to real-world concepts of soil erosion, vegetation’s role in protecting watercourses, and the impact of land degradation.
Reflect and Conclude:
Review the key concepts learned from the experiment, including the role of vegetation in preventing soil erosion and maintaining water quality. Encourage students to reflect on their observations and connect them to environmental protection.