Compost for a Cleaner World

Have you ever cared for a garden? If so, then you've probably heard the term fertilizer before. Gardeners mix fertilizer into soil to help their plants grow. But what is in fertilizer? It is a mix of plant nutrients that can be created by the decomposition of plant parts. You have been studying how energy and matter flow through a food web. You can be an active part of the cycling of matter by creating fertilizer!

Materials

A cutaway picture of a tin can with layers of soil.

Procedure

Have an adult family member poke holes in the plastic lid. Make a layer of dried plant parts, leaves, or pine needles on the bottom of the can, followed by a sprinkling of soil. Next, sprinkle this layer with a few drops of water. Every day, as meals are prepared, collect uncooked fruit and vegetable scraps (you can also use grass) and put them into the can. After you create this layer, make another layer of dry plant material on top of it. Make as many layers as your can will hold (there should be four to six layers). Each week, on the same day of the week, stir up the contents of the can. Store it somewhere relatively warm. After four weeks, your fertilizer will be done! Mix the fertilizer with the soil of an outdoor plant or houseplant.

Results

Why do you think that adding decayed plant matter to the soil of a plant would help it grow? What do you think caused the vegetable matter to decompose? What do you think the benefits to the environment might be if everyone started making their own plant fertilizer?