Understanding Compost: Creating your own Soil-arium

This week is all about soil and the importance of composting.

Do you compost at home? Have you ever thought about what is actually happening in your compost? Christine teaches us how to make our own soil-arium at home so we can observe and track the decomposition process that occurs when we compost organic matter turning it into nutrient-rich soil for our plants! Join us!

Why is Composting so Important?

Composting is an important process that recycles the nutrients in food - to be reused to grow more food. When we throw our food scraps into the garbage we lose those nutrients forever. Not only are we throwing away very important nutrients, but food scraps in the landfill release something called methane gas which contributes to global warming. By composting, we are saving valuable nutrients that we can use to grow more nutritious food - and we are also helping to protect our environment.

A great example of composting takes place on the forest floor! We don’t see people going to clean up all the fallen leaves, trees, branches, etc. This is because decomposers (living organisms) such as worms, fungi, beetles, and bacteria help break down these materials. By creating a soil-arium or compost, we are building a home for decomposers to do their important work! Even if you can’t see these organisms, they are there and busy helping to create soil for us. It is important we give these living organisms the things they need to survive!

Learning Objectives

• Be able to explain what composting is and why it is important

• Understand how to start a basic composting system

• Learn about the life cycle of food

Activity Preparation

Items needed:

Glass jar

Food scraps

Dirt

Organic yard debris

Old newspaper or cardboard

Water

Tape and marker

Set-up

Little to no set-up is required. Find a sunny windowsill spot where the soil-arium can be observed throughout the composting process (approximately 12 weeks).

Activity Instructions

1. Add a small handful of dirt to the bottom of your glass jar.

2. Add a layer of shredded newspaper or cardboard.

3. Add a layer of kitchen scraps.

4. Add a layer of organic yard debris.

5. Repeat this order of layering until your jar is almost full to the top.

6. Add your water and then cap the top with holes poked in the lid.

7. Draw a line to mark the top of your original composting pile.

8. Add a little bit of water as needed, and stir daily to provide oxygen and move around the bacteria so they can find new food.

9. Every two weeks, draw a line to mark the new top as the composting process continues.

Observing Changes in Your Soil-Arium

The composting process will be different with each person’s soil-arium. The composting process can take several months, so we can make some observations during this time.

Measuring/Tracking Compost:

1. On Day 1 of your soil-arium, mark and measure the height from the bottom of the container to the top of the pile of compost.

2. Every week or two, you can re-measure, and note changes in the height of the compost as things decompose.

3. How much water are you adding?

4. How big are the pieces of food scraps that you have added to your compost? We can help speed up the composting process by breaking down what we add into smaller pieces.

5. How heavy is your soil-arium?

6. You may want to try making some predictions of what may happen in your soil-arium over time.

Making Observations of the Composting Process:

1. You may want to try creating a journal to record and keep track of what you have added to your soil-arium.

2. What changes are you noticing with your soil-arium? After a few weeks, can you still see and identify all the food scraps that you have added? 

3. Have some of the food scraps decomposed more quickly than others?

4. Can you see any flies, worms, or other insects in your soil-arium?

5. How does your soil-arium smell? Adding more dry browns to the top layer in the Soil-arium will help it from getting stinky! Adding more browns will slow down the composting process, but it also helps from ‘drowning’ the compost with too much moisture - which can kill the living organisms responsible for composting.

6. How does the texture of it feel in your hand? Remember, healthy compost should have a similar moisture to a wrung out sponge.

Compost Recipe

Remember that your compost is a living thing, and it requires our love and attention to make it thrive - just like a pet! It needs a balanced diet of browns and greens, air, and water (as needed). 

Now, it is your turn to go find some browns and greens to add to your soil-arium!

How Plants Grow - Celery Experiment

This week, we are learning about how plants grow and how all the parts of the plant contribute to their growth. Here is a fun and easy way to demonstrate how the stem (also called a stalk or leaf stalk) of a celery plant carries water and nutrients all the way from its roots up to the leaves of even the tallest of plants.

You Will Need:

• A celery stalk (or two) with leaves still attached

• A cup or mason jar

• Water 

• Food Colouring (red or blue work best for this experiment)

Instructions: 

1) Cut the bottom inch off on the celery stalk.

2) Fill the jar about halfway up with water.

3) Add 5 or so drops of food colouring into the water (a few more drops if you have a larger vessel with more water).

4) Place the jar in a sunny location and wait 2 hours.

5) Observe the celery stalks. You may see the food colouring working its way up the stalk (moving through the xylem of the celery plant). Xylem are tiny tubes in the plant (like veins in our bodies) that move water from the roots to the leaves in a plant. Because we have added food colouring to the water, you should be able to see the colour as the water moves up the stalk toward the leaves.

6) Break off a small piece of the leaf stalk, you may see food colouring in the xylem.

7) Wait overnight. In the morning, observe your celery stalks and leaves. Did the food colouring make its way to the celery leaves?

Discussion Questions:

What happens to the water once it reaches the leaves?

• Some of the water is used by the plant’s leaves to make food through the process of Photosynthesis. Sunlight provides the energy for plants to make carbon dioxide (what we breathe out) and water into sugars (food) and oxygen (what we breathe in).

• Sometimes you might notice droplets of water on the ends of the leaves of a plant, this often is a good indicator for houseplants that the soil is very moist. When a plant has more water than it needs the leaves release some of this water to be evaporated into the air from its leaves. This process is called Transpiration and can actually help the plant take up more water.

How is the water and food colouring moving up the plant?

• The process of water moving from roots to leaves is called Capillary Action. Water molecules like to stick together and to the walls of the tubes that make up what is called a plant’s xylem. These tubes run from the plant’s roots, up the stem, and all the way up to their leaves. As water then evaporates from the leaves it pulls up more water from the roots helping water to move up the plant.

This week we’ve been talking about and learning the six different parts of a plant. In this activity, we learned about how the roots, stem, and leaves of a plant all work together to help it get the water it needs using a celery stem. When we eat celery we are eating the stem of the plant (also called a stalk or leaf stalk) of the celery plant.

• Think about what other stems, roots, flowers, seeds and leaves we eat on a regular basis. You may never look at your favourite vegetables in the same way! 

Expansion Activity:

Try using a large celery stalk and splitting it from the bottom to about halfway up the stalk. Place one half of the stalk into a container with blue food colouring and the other half into a container with red food colouring. What do you think will happen when the colour from each reaches the part of the stalk where the two halves are joined? What will happen when the colours reach the leaves?

Don’t forget to wrap up this experiment by enjoying a delicious celery snack. That’s right - this celery is still edible and yummy, so don’t let it go to waste!