Composting Investigation

Posted by David Wetzel

Composting

Composting can be accomplished in the home by using a large heavy duty plastic trash can with the bottom cut open and with holes in the sides. Types and designs of composting bins vary based on the level of composting.

The compost bin is typically placed in the back yard for convenience and because the compost bin tends to smell as the organic material placed in the bin decomposes. Creating compost is important because it becomes natural high-quality soil used for growing plants and trees; providing them with nutrients and helping to retain moisture.

Building a Composting Column in the Classroom for Investigation

This investigation is designed to allow students to build their own decomposition column for discovering how the compost process works. The compost column investigation is designed to take at least 2 months; however, it can be used as a year long science project.

Materials:

3 two liter bottles per group
2 cups of dirt
ML measuring cup
Duct tape
Fruit and vegetable scraps from home
Newspaper (to cover table when constructing the compost column and for placing small pieces of newspaper in the compost)
Plastic bag pieces
Scissors
Rubber band
Nylon stocking or other fine mesh cloth
Xacto knife
Celsius thermometer
Plastic spoon

Procedures:

Using the the xacto knife cut the three bottles as shown in “A” ( see the image to the right).
Cut several 2 cm by 1 cm holes in bottle 1 for air ventilation of the compost column.
Place a piece of nylon or fine mesh cloth over the cap opening of the bottle 2. Use the rubber band to hold it in place.
Make sure the bottles fit together as shown in “B” before moving on to the following steps.
Place alternating layers of dirt and food scraps in bottle 2. Also, place some pieces of newspaper and plastic within the layers of dirt and food scraps.
Tape bottle 1 and 2 together as shown “B” using thin strips of duct tape. Place the two taped bottles on top of bottle 3.
Pour enough water through the opening at the top of the compost column to ensure the dirt is moist (be careful to make the dirt moist and do not over water)
Record what food scraps, amount of newspaper and plastic, amount of water used, temperature of compost dirt when complete, and observations of the compost when complete.
Once a week record date, temperature of compost dirt (Celsius), amount of water in bottom (ML) and pour the water into the top of the compost column after measuring, any odor, evidence of organisms, all observations of the compost column, take digital pictures for the project report when significant changes occur, use the plastic spoon to mix the compost after collecting all data for the week

Making Connections:

When the project is complete prepare a multimedia presentation of the project to show the class and write a report about the compost column investigation.

Information required as minimum for the multimedia presentation include: