This project determines the age of a tree using a growth factor chart instead of cutting the tree down to count the rings in its base.

This science fair project idea identifies trees using a dichotomous key.

This science fair project compares the allelopathic affects of juglone, a chemical agent produced by the Black Walnut tree, on two plants.

This science fair project idea deals with the qualities of shade on a sunny day.

Is horse manure a possible energy source in a crisis? Use calorimetry to find out how much energy horse manure can produce in this science fair project.

This science fair project idea explores alcoholic fermentation at work by making your own soda.

What is mulch? Kids will provide soil with a wet blanket of mulch and see if that helps keep drought-stricken soil damp.

This science project has students collect wood samples and invent new uses for different types of wood based on its properties.

This science fair project teaches you about what makes persimmons so tart and how astringency can be removed by studying the effect of tannins on fruit.

This science fair project idea provides evidence that air is everywhere and takes up space.

You've heard the expression "burn rubber" but do you know how heat affects rubber? Examine the impact of temperature on rubber in this fun science experiment.

Kids learn about examples of mechanical weathering and conduct an experiment with seeds and plaster in this cool geology science fair project idea.

Soil is made up of different layers. How far down do you need to dig to find the soil horizon, or the place where bits of leaves and branches become soil?

The objective of this science fair project is to study the photosynthesis process and demonstrate the important role that leaves play in the process.

This science fair project idea measures out the sugar of various foods and find out whether people can correctly determine how much sugar is in common foods.

What is biodiversity? Kids will study different areas of their backyards to see which is the most diverse to learn about biodiversity and random sampling.

Here is a cool and easy science project to determine the rate of chlorophyll breaks down and how it affects the color change of grass from green to yellow.

Kids conduct a cool balloon rocket experiment in this fun science fair project idea. Does a greater volume of air mean a greater distance traveled?

This science fair project teaches students about wilting and browning of salad greens.

In this fun project, use a memory game to test various age groups and determine whether aging directly affects short-term memory loss.

Check out this cool science fair project on identifying rocks and minerals for kids.