Soils Chapter

1
Soils Chapter
2
Todays key terms

• Soil
• Mineral matter
• Air
• Water
• Living organisms
• Humus

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What is soil

• Soil is the thin layer of loose material on the
  earths surface.
• Plants grow in it.
• It is a natural resource.

4
What is soil made up of

• Mineral matter
• Air
• Water
• Living organisms
• Humus

5
Mineral matter

• This is the largest ingredient in the make up of
  soil.
• Mineral matter is the remains of rocks.
• It looks like gravel and silt

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Air

• Air is in the space between the soil particles.
• Air is important for the growth of roots
• It is also important in the formation of humus.

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Water

• Water is important as it contains dissolved
  minerals.
• These minerals provide plants with important
  nutrients that are required to grow.

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Living organisms

• These included
• Earthworms
• Slugs
• Woodlice
• Insects
• Bacteria
• Fungi
• The bacteria and fungi in the soil helps to break
  down dead plants to form Humus
• This Humus increases the fertility of the soil

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Humus

• Humus is the decayed creatures, plants and
  litter.
• Humus provides the soil with nutrients.
• Humus increases the fertility of the soil

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Soil formation

• Soil formation can be influenced different
  factors and they included
• Climate
• Parent Rock
• Vegetation
• Micro-organisms
• Time
• People

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Soil formation
Climate
Vegetation
Parent Rock
Micro-organisms
All Mix to form
Soil
Time
People
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Climate

• Climate affects the following
• amount of rainfall
• The temperature
• All of this affects the amount of vegetation
• Back

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Parent Rock

• Climate influences the amount of
  erosion/weathering that occurs to rock in a
  region
• This influences the amount of mineral matter that
  is present in the soil.
• Back

14
Vegetation

• Influenced by the climate
• The type of Vegetation
• The amount of Vegetation
• Back

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Micro-organisms

• These Micro-organisms break down the vegetation
• The amount of vegetation dictates the amount of
  humus in the soil
• Back

16
Time

• The amount of time soils is allowed form dictates
  the type of soil that forms.
• It takes approx 400 years for 1cm of soil to
  form.
• Back

17
People

• People can alter the formation of soil
• Irrigation, drainage or fertilizing all make the
  soil more fertile
• OR
• Overuse make the soil les fertile.
• Back

18
Homework

• Update all your notes
• and
• Question 1 on page 183

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Todays key terms revised

• Soil
• Mineral matter
• Air
• Water
• Living organisms
• Humus

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Todays Key Terms

• Soil profile
• Horizon
• Leaching
• Hardpan
• Brown Soils
• Podzol Soils
• Peaty soils
• Gley soils

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Last classes terms revised

• Soil
• Mineral matter
• Air
• Water
• Living organisms
• Humus

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Soil profile

• Soil is made up of different layers
• Each layer is called a horizon
• Each layer is labelled with a letter

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Soil profile of a litter plant

• Horizon A
• This is the upper layer
• It is made of topsoil
• It has a high Humus content
• It is dark in colour

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Soil profile of a litter plant

• Horizon B
• Found underneath horizon A
• It is called a subsoil
• Less Humus more stones
• Lighter colour

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Soil profile of a litter plant

• Horizon C
• Is the layer of parent rock

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Leaching

• This is the washing of nutrients from one horizon
  to the other.
• This can cause the loss of fertility in horizon A
• If leaching is severe it can result in hardpan
• This is grey in colour and is impermeable.
• This can result in a field been very wet as water
  cannot soak into the ground.

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Irish Soil

• There are four main types of Irish soils they
  include
• Brown Soils
• Podzol Soils
• Peaty soils
• Gley soils

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Brown Soils

• Found in area where deciduous trees used to be.
• Horizon A is rich in humus
• Horizon B has a blend of horizon A due to worm
  action
• Horizon C is made of bedrock
• This is a very fertile soil

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Podzol Soils

• Found in area where coniferous trees are found.
• These are mainly found in cold climates
• Horizon A has low levels of humus
• Cold weather has limited worm activity
• Between horizon A and horizon B a hardpan may
  develop.
• Horizon C is made of bedrock
• This is a very infertile soil

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Gley Soils

• Develop in areas where the bedrock is
  impermeable.
• Or there is a band of hardpan above the parent
  rock bed

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Peaty soils

• Develop in high upland areas.
• Areas with high rainfall
• Results in water logged land

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Todays Key terms

• Tropical red soil
• Climate
• Chemical weathering
• Iron oxide Leaching
• Infertile
• dd

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Last classes Key Terms

• Soil profile
• Horizon
• Leaching
• Hardpan
• Brown Soils
• Podzol Soils
• Peaty soils
• Gley soils

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Tropical red soils

• Found in areas that have tropical or equatorial
  climates.
• Formation influenced by hot, wet climatic
  conditions.

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Tropical red soils

• Formation
• The formation/make up of this soil is different
  to Irish soils.
• Continuous leaf fall
• Therefore thick layer of litter
• This is broken down due to
• Mirco-organisms
• Hot, wet climatic conditions.

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Tropical red soils

• Formation
• The acid from the humus assists the weathering to
  the parent rock
• The erosion is also aoded by the high
  temperatures
• The weathering of the rocks breaks down the iron
  oxide in the soil.
• This gives it a reddish colour.

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Tropical red soils

• Is the soil FERTILE OR INFERTILE
• Normal conditions very fertile due to continuous
  leaf fall.
• HOWEVER
• When the forest are cut away the soil suffers
  from leaching due to heavy rainfall.
• This leads to the soil becoming infertile.

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Natural vegetation and soil

• Soil influences vegetation
• The soils fertility dictates how much the
  vegetation grows
• Vegetation influences soil
• The vegetation dictates the amount of humus in
  the soil.

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Soils influences on vegetation

• Fertile soil
• The more fertile the soil the more it can support
  strong growth.
• Infertile soil
• Lack of nutrients can limit the amount of growth
  that soil can support. Typical vegetation would
  include coniferous trees.
• Soil depth
• Trees such as oak and beech need a large depth of
  soil because of there deep roots and there need
  for nutrients.

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Vegetations influence on soil

• Humus role
• Binds soil
• Nourish soil
• Influences the colour of horizon A
• Vegetation reduces the effect of leaching
• Roots absorb the leached nutrients
• Vegetation reduces soil erosion
• Roots bind the soil
• Roots absorbs some of the water content in the
  soil.