Look around you. Soil covers almost all of Earth’s land. We walk on soil in the woods, in parks, even in our own backyards. Engineers build houses and buildings on its surface. Soil is the place where plants and trees grow, making it a big part of agriculture.
Soil is home to millions of tiny soil organisms (living things), from one-celled bacteria to ants, earthworms, and other small animals. These organisms interact with one another, and with their environment (the world around them). Similarly, when the soil environment changes, soil organisms are affected.
Humans have always changed the soil in many ways, but today, we are changing the soil in ways never before seen. Pollution, pesticides, irrigation, and global warming are all having major effects on the soil and its organisms. Scientists are trying to understand these effects.
Most importantly, soil is an important resource. Growing our food relies on farming, which relies on having good soil. Once soil is damaged, it is very hard to replace. For this reason, environmental factors that harm the soil (such as pollution, erosion, and other forms of soil degradation) can threaten soil quality. The study of soil helps give us valuable information as society struggles to find solutions to these problems.
Soil photo from soil-science info's photostream.