GLOBE NY Metro, 2008

Great integrator Medium of crop production
Producer and absorber of gases (CO
2 and others)
Medium for plant growth
Medium of heat and water storage
Home to organisms
(plants, animals and others)
Snapshot of geologic, climatic, biological, and human history
Waste decomposer
Source material for construction, medicine, art, etc.
Essential natural resource
Filter of water and wastes

Soils are very different, depending on how they form
United States Department of Agriculture

4 factors control soilforming processes
Living things
Climate
Topography
Parent Material
Photo courtesy,
Ray Weil, PhD
TIME is the 5 th factor
Soil forms by the interaction of the first four factors. It changes to create soil profiles unique for the conditions and elapsed time . A soil profile consist of layers called “soil horizons”
During the GLOBE
Soil
Characterization protocol, you will describe, sample, and analyze soil horizons near your school

ROLES OF THE FIVE FACTORS OF SOIL FORMATION
Living things: Plant roots physically break rocks into small pieces; lichen dissolves rock; burrowing animals mix the soil and help aeration
Climate: heat and water accelerate chemical changes (so moist, temperate areas like NYC have different soils than arid, tropical, or polar areas).
Topography: Loose soil stays in place in flat areas, allowing more thorough physical and chemical alteration of its grains. On steep slopes, the soil moves downhill before complete alteration can occur.
Parent material: Chemical changes during soil formation depend on what minerals and rocks are present. Example: Calcium-rich soils generally form from calcium-rich rocks (like limestone) but not from calcium-poor rocks like granite.
TIME : When bedrock is exposed at the surface, chemical, biologic, and physical processes combine to produce a thin soil layer. Over time, the processes extend vertically downward, developing soil horizons whose position and thickness change over time.

If all five factors are the same in two geographic regions, the soil will be the same in both. Some basic examples of different soil types include:
Temperate deciduous soil
Tropical rain forest soil Desert soil
Grassland soil

Atmosphere
• Dew (moisture from the air ) begins chemical alteration of parent rock
• Rain erodes loose soil, preventing further alteration
• temperature controls rate and extent of chemical processes
Hydrosphere
• Water seeps into the ground, dissolving and redistributing elements
• evaporation dries soil, changing its physical characteristics
Biosphere
• plants add and remove chemicals
• plant roots anchor soil in place, enabling chemical reactions to be completed
• animals mix soil; transport seeds, etc.
•
•
Geosphere solid rock and unconsolidated sediment are the parent material for soil geologic processes (surface and internal) expose and bury rock, etc.

Structure
Soil Properties related to the hydrologic cycle.
Soil moisture Color
Temperature pH
Texture
Horizon
Depths
Bulk Density