Soil Health

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Soil Ecology
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• Soil Health

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• http//www.soilhealth.com/index.htm
• Welcome to soilhealth.com
• Soils Are Alive!
• This website was begun to provide background
  information relevant to soil health and the
  sustainable use of land for agriculture,
  horticulture and other practices, including
  forestry.
• The website emphasizes the biological processes
  in soil.
• We are developing links to soil chemical and
  physical components of soil. These will be
  inserted shortly.
• Acknowledgments Website Development funded by
  Ian Potter Foundation

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Soil Health?

• the minimization of the number and activity of
  soilborne plant disease organisms and soilborne
  insect pests.
• (narrow definition?)
• Soil health is the capacity of soil to function
  as a vital living system with ecosystem and
  land-use boundaries to
• sustain plant and animal productivity,
• maintain or enhance water and air quality, and
• promote plant and animal health. (Doran and
  Zeiss, 2000, Applied Soil Ecology 153-11)

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Soil Health?

• integration of biological with chemical and
  physical approaches to soil management for long
  term sustainability of crop productivity with
  minimal impact on the environment .
• (Wolfe in 2000 in Applied Soil Ecology
  153-11, Duran Zeiss)
• Capacity of the soil to function as a vital
  living system (Trutmann in 2000 in Applied Soil
  Ecology 153-11, Duran Zeiss)
• to sustain biological productivity,
• promote environmental quality, and
• maintain plant and animal health
• So managing a healthy soil is managing the living
  portion of the soil to maintain the essential
  functions of the soil since inert components
  cannot be sick or healthy.

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• Soil Quality (Soil Survey Division 1995)
• capacity of the soil
• to sustain plant and biological
  productivity,
• to maintain environmental quality, and
• to promote plant and animal health.

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• Soil Quality(Soil Science Society of America
  1999)
• capacity of the soil to function within
  ecosystem boundaries,
• to sustain biological productivity,
• to maintain environmental quality, and
• to promote plant growth.

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Soil Functions

• Providing a physical chemical environment for
  gas, nutrient, water, and heat exchange for
  living organisms
• Regulating the distribution of surface water to
  runoff or to infiltration, storage, and deep
  drainage

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Soil Functions

• Providing mechanical support for living organisms
  and their structures
• Buffering the life support system against
  thermal, chemical, gaseous, or other stresses
• Acting as a source, sink, and filter reducing
  contaminants that affect water and other resource
  quality.

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Soil Quality

• Soil Quality capacity of the soil
• to sustain plant and biological productivity,
• to maintain environmental quality, and
• to promote plant and animal health
• AND support human health and habitation.
• Soil Health?
• Perhaps quality productivity and health
  sustainability (live system)

some suggest it is the evaluation of soil
quality over time???
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Sensitive indicators of Soil Quality

• Indicators?
• Physical
• Chemical
• Biological

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Sensitive indicators of Soil Quality

• Physical indicators
• Soil texture and aggregation
• Depths of soil, topsoil, rooting
• (erosion)
• Bulk density
• Infiltration rates
• Water retention characteristics

(Doran Parkin 1996)
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Sensitive indicators of Soil Quality

• Chemical indicators
• Total organic C and N
• pH
• Electrical conductivity
• Extractable N, P, K

(Doran Parkin 1996)
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Sensitive indicators of Soil Quality

• Biological indicators
• Microbial biomass C and N content
• Potentially mineralizable N
• Soil respiration
• Water content
• Soil temperature

(Doran Parkin 1996)
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Soil crust (light areas) dry quickly after a rain
vs grass-covered soil. Soil crusts tend to shed
rain, rather than absorb it.
Soil crusts - capping vs Biological crusts
algal or cryptogamic
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S.E. Cornelius/Photo Researchers, Inc
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pH as another sensitive indicator of soil health
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How can we determine soil health or quality???
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Soil Health ???

• Bioindicator can integrate condition
• of other factors/functions

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Fungal indicators
For example, the decrease in fungal abundance
observed from disturbance (ie, agriculture,
logging, reforested sites) appeared to result in
decreased nitrogen mineralization over the long
term. (Fraterrigo et al 2006)
Presence of Mycorrhizas??
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Communal Property and the Tragedy of the Commons

• Tragedy of the CommonsOpen access systems - have
  no rules to manage resource use (1968, Garret
  Hardin)
• Commonly held resources are degraded and
  destroyed by self-interest
• Monitor soil health?
• Management can affect soil health!!

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Management can affect soils and their health
which can then also affect productivity
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