Terrarium Habitats a GEMS guide by the Lawrence Hall of Science includes a great soil observation activity, including the soil separation test and Tullgren Funnel test.
The Open Door Website describes the Tullgren Funnel test with pictures and additional details.
Shaping Earth's Surface
2. Topography is reshaped by the weathering of rock and soil and by the transportation
and deposition of sediment.
Ecology (Life Sciences)
5. Organisms in ecosystems exchange energy and nutrients among themselves and with the environment. As a basis for understanding this concept:
e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition.
5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept:
e. Students know how to determine whether a solution is acidic, basic, or neutral.
Investigation and Experimentation
7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.