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?

Science fair project which tests various sedimentary, igneous and metamorphic rocks to find out whether one rock family is stronger than the others.

How do organic materials become soil? This science experiment measures what materials biodegrade.

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

Science fair project that compares the ecology of different soil samples by identifying which sample has the most invertebrates living in it.

This science fair project idea measures and compares effects of chemical weathering, specifically carbonation, on different kinds of rocks.

The objective of this science fair project is to test the growth rate of a plan in a crystal medium in comparison to traditional soil.

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

Science fair project that examines the behavior of water and gravel in creek beds and the formation of sedimentary rocks.

This science fair project idea studies which kind of rock (sedimentary, igneous, or metamorphic) is most damaged by frozen water.

Determine which kind of rock (igneous, sedimentary, metamorphic) has the greatest reservoir capacity, which is the ability to hold the most oil and natural gas.

In this experiment, students will discover how heat and pressure turn clay into slate, phyllite, and finally schist.

What heats up fasterâwater or soil? 5th grade students test the specific heat of water against the specific heat of sand in this great science fair project.

Ant behavior is closely related to light intensity. This free science fair project idea examines how fast ants dig when they are exposed to to light and dark.

In this science fair project, students create their own miniature salt flats at home.

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

This science fair project idea creates a sedimentary rock and to investigate what takes place during the rock cycle.

Science fair project which determines whether plants are able to get enough nutrients from different types of garbage.

Watch pre-packaged seeds and seeds taken from inside fruits and vegetables grow. Which ones will grow faster? Read more in this science fair project idea.

This science fair project idea researches the definition of ‘biodegradable’ and explores this in a real-life setting.

Science fair project that determines whether landscaping fabric impacts the ability of plants to receive water.

This project demonstrates the correspondence between the volume of water displaced by a submerged object and the volume of the object displacing it.

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

Find out whether packaged seeds actually do expire in this new science fair project idea.

Explore if planting seeds in a certain direction will affect how fast it germinates.

Find out whether putting something on top of a plant will inhibit its growth.

The objective of this science fair project is to set up a compost bin to convert food scraps and organic waste.

In this science fair project, students discover how sedimentary layers form as sediments like mud, silt and sand settle over time.

Learn about the effect of artificial light on plant growth versus natural sunlight and delve into some biology and botany concepts in this science project.

Examine whether distilled water, spring water, or regular tap water yield faster plant growth.