1. SOIL AND ITS FORMATION

2. Components of Soil Viewed in layers
Each layer has different texture and color
Deeper into the soil there is less organic matter

3. Litter Upper layer in forests and grasslands
Made up of decomposed legumes and grasses
Like a blanket

4. Topsoil
Made up of small particles of rock mixed with decaying plant and animal material (called humus)
Rich supply of minerals and nutrients
Air and water
This is topsoil

5. Subsoil Contains more stones Small amounts of organic matter
Lighter in color because of lack of humus
This is subsoil

6. Bedrock Layer of rock beneath the soil Marks the end of soil
This is bedrock

7. Formation of Soil Begins as bedrock
Broken down into smaller particles by rain, wind, frost, snow, living things (called weathering)
Small plants start growing
Plants speed up weathering, decompose and add to topsoil
Larger plants can grow

8. Soil pH Soil can be acidic, neutral or basic
Determined by the type of rock and plants from which it formed
Decomposition of organic matter from dead plants or leaves cause acid accumulation
Rain and snow, ground water, humans burning fossil fuels
SO2 and nitrogen oxides form acidic compounds in in the atmosphere as acid rain or snow

9. How can the pH of acidic soil be raised?
Acidic Water in Soil
Causes extreme leaching
Leaching: when nutrients and minerals in the soil are dissolved in percolating water and carried into lower layers of soil or bedrock
Fertility of soil is reduced
Plants grow slower and are vulnerable to diseases
pH of the soil determines switch plants grow best
Examples:
Conifers do bad in acidic soil(needles turn yellow and brown)
Mosses love acidic soil due to little competition
How can the pH of acidic soil be raised?

10. THE END