University of Missouri
Soil Health Laboratory
University of Missouri Soil Health, Soil
Characterization
and Geotechnical Analyses Laboratory
Service in the Land Grant Tradition
Donna Brandt
Research Specialist
Who are we?
• Soil Health Laboratory grew from
the Soil Characterization Laboratory
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Operational since funding in 1984
Soil analyses equipment
Experienced personnel
University of Missouri Department
of Civil and Environmental
Engineering
• Laboratory expanded for soil health
evaluation
– Additional space,
– New equipment and analyses
Goals
Be Quantitative—Measure indicators of soil
functions:
Chemical Physical Biological
Be Soil Specific—Compare soil indicator values to:
Established soil interpretative data
Compare “health” soils to others
Expand and complete existing data base
Be Prescriptive—Identify limiting soil attributes
Develop and Establish Scientific Underpinnings for
soil health:
What works?
How are soil health values related?
How long until a difference is made?
Soil Carbon
Active Carbon
is soil organic
carbon actively
being broken down
and transformed
by soil organisms
releasing
nutrients and
building soil
structure
Total Organic Carbon
estimates the
total carbon
found in soil
organic matter
Soil Nitrogen
Potentially Mineralizable
Nitrogen
• Estimates amount of nitrogen
made plant-available through
the growing season as soil
organic matter transformed
and recycled.
• Reduces nitrogen inputs for
the next crop because the soil
will provide it.
Total Nitrogen
• Total nitrogen in soil
• Some not available to plants
Soil pH
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can assist growers in either growing crops to suit their soil pH or amending their
soil to a pH better suited to the crops they want to grow. The proper pH allows for
maximum nutrients to be available to plants. Without the proper pH nutrient
additions are wasted because they remain unavailable to plants.
Effective Cation Exchange Capacity
Capacity of soil to hold cations
calcium
magnesium
potassium,
sodium,
hydrogen
aluminum
at the current soil pH (not 7).
• Allows future improvements
in CEC to be measured.
• Basic:acidic cations
• Nutrient balance
Exchangeable
Bases
Base Saturation
Wet Aggregate
Stability
Measures soils’ ability to:
• Resist erosion and crusting,
• Promote water infiltration,
• Hold water to reduce
drought effects,
• Promote root penetration,
• Cycle nutrients,
• Remain viable during
conservation tillage.
Bulk Density
• Measures compaction and estimates pore space.
• Estimates root restricting conditions,
• Allows conversion of soil weight to soil volume –
measures improved soil health attributes.
Phospholipid Fatty Acid Analyses (PLFA)
• Estimates microbial biomass,
• Approximates microbial
community composition
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Gram positive bacteria
Gram negative bacteria
Actinomycetes
Mycorrhizae
Saprophytic fungi
• Indicates stressed organisms
• Samples must be kept cool or
frozen
• Sensitive to time of year
• Relationships to other soil
health values?
Other
• Additional tests available through Soil
Characterization Laboratory
• Soil Health Analysis Packages
• Individual soil tests
• Add new analyses
Why?
• Compare effectiveness of
management systems.
• Compare to soils with native
vegetation (target baseline).
• Baseline data before changing
management systems.
• Detect changes through time
after a change in management.
• Determine PMN to reduce
fertilizer expenses.
• Evaluate soils in fields before
buying or renting.
Where?
• Where your hypothesis
would be tested:
• Variable
• Control
• Sample soil map units
(series).
• Sample landscape positions
• Stable
• Erosional
• Depositional
When?
• Spring.
• Fall.
• Appropriate moisture content—not
saturated.
• Be consistent.
• Every 3 or 4 years—depends on
rates of soil change or crop yield
improvements.
How deep?
Know what soil you
are sampling --tillage
depth or surface
horizon
Subsoil sampling may be appropriate
• Possible subsoil compaction,
• Examine chemical properties – potential for
nutrient cycling,
• Evaluating long term management.
What tools are needed?
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Shovel or trowel.
Density sleeve and knife for bulk density.
Sealable plastic bags and a box to hold them
GPS or aerial photo—note sample location.
Optional--Notebook to record observations:
• Soil texture structure
• Moisture
• Thickness of surface horizon
• Soil organisms present (worms, ants, etc.)
• Rooting patterns
Packaging
• Approximately 2 cups soil per sampling site
or
• Density sleeve sample (from standard 3” density
sleeve)
• Plastic bags supported by a box (to protect moist
aggregate stability samples)
• PLFA sample--ship with frozen gel packs overnight
(not over a week end)
• Addressed to: Soil Health Laboratory
Department of Civil and Environmental Engineering
E2509 Lafferre Hall
University of Missouri
Columbia, MO 65211
What information is needed?
• Location, location, location
• Decimal degrees ideal
• GPS, internet mapping, address locators,
CARES, aerial photos
• Field name or identifier
• Sampling date
• County
• Soil map unit
• Rotation
• Tillage history
• Cover crop history