Soil and Soil Conservation

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Soil and Soil Conservation

• Why are they important?

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What is soil?

• According to the Natural Resource Conservation
  Service soil refers to the loose surface of the
  earth as distinguished from rock.
• Soil is composed of organic matter, mineral and
  nutrients
• An average soil sample is 45 mineral, 25 water,
  25 air and 5 organic matter
• Soil texture comes from different size mineral
  particles such as sand, silt and clay

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Soil Horizons

• O Horizonorganic layer
• A Horizontopsoil
• B Horizonsubsoil
• C Horizonsubstratum
• R Horizonbedrock

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Soil Forming Factors

• There are 5 factors that contribute to the
  formation of soil
• Parent material
• Climate
• Living organisms
• Landscape position
• Time

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Soil Forming Processes

• Four major processes change parent materials into
  soil
• Additions
• Losses
• Translocations
• Transformations

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Soil Structure

• Soil texture is determined by the distribution of
  sand, silt and clay.

Figure 1
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Soil Classification

• In soil classification, soils are grouped on the
  basis of properties at various levels or
  categories.
• The lowest and most detailed level is the
  individual kind of soil or soil series that is
  given a place name, such as Drummer, Tama, and
  Hickory.
• The soil order is the highest and most
  generalized level.

Drummer
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Soils in our region

• Loess is the most extensive soil parent material
  in Illinois. Soils developed primarily from loess
  occupy about 63 percent of the states land area
  (loess is a silty wind deposit that was deposited
  during glacial times)
• The most recent loess blanket in Illinois
  (Peorian loess) was deposited 12,500 to 23,000
  years before present
• Soil parent materials deposited in association
  with glacial ice are called glacial drift.
  Glacial drift includes glacial till, glacial
  outwash, and glacial lacustrine deposits
• Most of the glacial drift in Illinois was
  deposited during the Wisconsinan (11,000-60,000
  years BP) and Illinoian (60,000-330,000 years BP)
  glacial stages

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Soils in Lake County

• There are 11 soil associations in Lake County
• Each association is further broken down into
  individual soil series
• A detailed description of each soil series is
  found in the Soil Survey for Lake County
• This survey is used by engineers, developers,
  homeowners, farmers and others to make their
  decisions regarding land use

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Why should we care about soil?

• Soil Erosion
• Raindrop erosion
• Sheet erosion
• Rill and gully erosion
• Streambank and bed erosion
• Wind erosion

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Erosion
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Erosion impacts

• Erosion from construction sites
• Surface water quality
• Fish and aquatic organisms
• Chemical pollutants
• Damage to wetlands and aquatic plants

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Erosion Impacts
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What can be done?

• Best Management Practices (BMPs)
• Illinois Urban Manual--is a technical manual
  containing best management practices (BMPs) for
  soil erosion and sediment control, stormwater
  management and special area protection
• Go native
• Education

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Soil Exercises

• What soil results from a 10 clay, 80 sand and
  10 silt?
• What about 30 clay, 10 sand and 60 silt?
• 15 clay, 65 sand and 20 silt?
• 20 clay, 20 sand and 60 silt?
• What is the dominant soil type and its
  description for sheet number 61?

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Questions?