Robert Gardner 
Soil [PDF ebook] 
Green Science Projects for a Sustainable Planet

What is soil? How do plants grow in soil? How is contaminated soil cleaned? Using the scientific method, readers will explore Earth’s soil and learn how to protect it. This informative and entertaining text will encourage readers to explore scientific ideas about the properties and importance of soil. For readers who are interested in entering science fairs, many experiments are followed by additional project ideas.