Supplies:
- Plastic cup with a lid
- Plastic wrap and a rubber band (if a lid is not available)
- Gravel, with scoop
- Soil, with scoop
- Seeds
- Spray bottle of water
- Small jar filled with soil
- Small jar filled with air (an empty jar)
- Small jar filled with light (an empty jar)
- Small jar filled with water
The four elements in the jars are essential for not only plants, but for all of us, to live.
a. Soil is where plants grow. Soil is made of rock broken down by weathering (physically - by wind, water, the sun, or ice; or chemically - by chemical processes that either destroy or create minerals) and organic matter from decomposed plants and animals. Soil has nutrients and minerals in it that plants use to grow. Soil also helps plant roots receive water. Sometimes water - river, floods, and heavy rains - wash away the rich soils that plants need to grow. This is called erosion.
b. Air is a mixture of gases in the Earth's atmosphere. Oxygen, carbon dioxides, nitrogen, hydrogen, argon, neon, and helium. These gases are necessary for plants (and us!) to breathe!
c. Sunlight is a source of energy known as solar energy. Sunlight keeps the Earth's surface warm. The temperature of the Earth's surface is dependent on how much sunlight is able to reach the Earth. Plants use this energy from the sun, combined with carbon dioxide in the air, and water to create sugar. This process is called photosynthesis, and it helps plants grow.
d. Water travels in a cycle called the water cycle. Water can be found in this cycle in three forms: a liquid (like the pond Frannie lives in), a solid (ice and snow, brr!), and a gas (water vapor - the clouds). Water is vital to all life on Earth - plants, animals, humans, and especially fish like Frannie! Can you think of a few examples of how plants, animals, and people use water?
Instructions:
1. Fill your plastic cup with about an inch of gravel.
2. Add a little water to your gravel - you have just created a model aquifer! The gravel represents the fractured rock and soil under our feet and the water that fills the spaces in between the gravel represents groundwater.
3. Cover the gravel with soil so the cup is about 3/4 full.
4. Plant your seeds. Read your seed packet for planting instructions, typically seeds do not need to be planted deep.
5. Water your seeds. As you add more water, watch how the water moves through the soil, this is how rain and snow recharge aquifers.
6. Cover your cup with a lid or rubber band plastic wrap around the top.
7. Place your cup in a sunny location.
8. Over the next few days, watch as the sides of the cup become foggy, this is condensation. Heat from the sun causes water to evaporate from the soil and become water vapor, then it cools as it touches the sides of the cup and condenses to become liquid again.
As the water on the sides of the cup becomes heavy, it will fall back to the soil, as "rain," and will water the seeds. Some of the water will move deeper into the soil and reach the gravel layer in the cup, becoming groundwater.
This is the same process as the water cycle. Water on the surface evaporates and moves into the atmosphere. When it cools, it forms clouds and eventually falls as precipitation (rain, snow, sleet, hail). The water then either runs off to surface water (streams, rivers, lakes, oceans) or soaks into the ground and might eventually become groundwater.
Be sure to share pictures of you creating your own terrarium!
