Creating a Compost Pile

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SWBAT predict and observe what happens to dead plants in soil.

Big Idea

What happens when you mix dead plants and soil together?

Setting the Stage

National Science Teaching Standards

Earth Science

  • Types of resources

Resources are things that we get from living and nonliving things to meet our needs such as: rocks, soils, water, and air.  This lesson focuses on students learning about composting.  Composting helps recycle certain foods and turn them to humus. Students learn what they can put in the compost such as: fruit, vegetables, scraps, leaves, live worms and insects.  Explain that composting is a way to recycle certain foods and turn them into humus. You can humus to soil to help with reproduction of plants. Also, this lesson helps to support 2nd grade Tennessee Standards.

Science and Engineering Practice: 

SP 1 addresses asking questions.  In 2nd grade, it is important that students ask questions about their investigation, so they can understand why and how things occur. In this lesson, students ask questions about how soil changes overtime when you add scraps and water to soil. Students learn that the items begin to decompose or break things down in order to add nutrients to soil which helps the soil and eventually the plants. 

SP 8 addresses obtaining, evaluating, and communicating information in K–2. Students communicate information with others in oral and written forms to discuss scientific ideas.  In this lesson, groups communicate with each other about their observation about the compost.

Prior Knowledge:

Students understand Earth resources. They know that Earth resources are air, water, plants, animals, soil, and rocks. They know that these things are non-living things that are a part of Earth. Students know that plants can grow in soil and it provides the plant with nutrient. They do not know that soil, food scrapes, and live worms and insects can promote humus which can be use to help plants grow more effectively.

This investigation takes a week.

Junior Scientists:

In my class, my students are called Junior Scientists. They wear lab jackets that they created early in the school year during their experiments. I call them scientists to empower them to major in science and math related careers. I want them to discover a love for science and math. Also, we sing "It is Science Time" before each lesson. 


Here is a website about soil. Also, your class can contact a soil scientist to ask questions about soil.



10 minutes

While students are at their desks, they watch a video on composting. In permitting the students to observe the video, it allows my auditory students to be engaged and motivated. Also, my students can retain taught concepts.


20 minutes

As a whole class, the students are engaged in the following experiment “All Mixed Up”. I inform the students as a class that we are going to create and observe a compost pile. All students are provided with a lab sheet.  The investigation is completed as a whole class because I want to provide all students to be engaged in the inquiry process. When students work in groups, some students tend to be aggressive and my quieter students are not contributing to the investigation.

 I inform the students to observe and ask questions about the items that they see if front of them, clear plastic container, lunch scrap, and potting soil.  The students are instructed to write 2 questions about the items that pertaining to the investigation, “All Mixed Up”.  The students can reference to the question stem anchor chart in the front of the class to help with developing the questions.  Students share some of the questions with the class. Some students share their questions because some students are still learning how to develop great questions that focus on our investigation.  

I have the students to formulate a hypothesis.  I provide them with a sentence starter,“If I mix the soil and lunch scraps, then ________________ will happen. “ I provide them with the starter due to some of my younger students are still learning how to develop a hypothesis that they can test or observe.

Students complete the “Plan the Test” section. Some students are invited to share their plan. I call on a few students to add the soil, lunch scrap, and water to the compost pile.  

Students are made aware that they are to add scrap and water to the compost pile, daily for 5 days. They also are required to stir the mixture. They record what they observe and add as a class.

Day 1- Creating our compost pile

Day 3

Here is our compost-video.


10 minutes

On the fifth day, the students are asked: How is the soil changing? They are instructed to write it on their lab sheet.  Also, they are invited to share some of their responses. I take up the lab sheets to ensure that students successfully completed the lab sheet and that they noticed a change in the soil and the food scraps.

Also, I inform the students that creating compost pile helps with reducing waste because we are reusing food scrapes. This helps to cut down pollution.  Also,a compost pile can help prevent erosion and help plants grow more effectively.

Student work, Mixed Up-Lab Sheet




10 minutes

Students add live worms to the compost and they continue to add food scraps and water, every other day. Students are continue to make observation, so they can see have the worms interact in the compost.

After they create enough humus, as a class, we can add it to soil and plant seeds. I permit my students to continue the investigation, so they can see how humus helps the soil and the plants.