72nd SWCS International Annual Conference July 30-August 2, 2017 Madison, WI

1. Developing Criteria for Soil
Health Interpretations
Science of
Interpretations
Maggie Payne
Robert Dobos
Shawn McVey
Lindsay Hodgman
Maxine J. Levin
USDA NRCS
Soil Science Division
maggie.payne@ma.usda.gov

2. Core Mission of the Soil Survey Program
1. Make an inventory of the soil resources of the U.S.
2. Keep the soil survey relevant to ever-changing needs
3. Interpret the information and make it available in a useful
form
4. Promote the soil survey and provide technical assistance
in its use for a wide range of community planning an
resource development issues related to non-farm and farm
uses

3. Soil Data Organization
Soil Survey Legend Consists of:
• Soil Map Unit (with a minimum map unit size)
– Soil Component/Soil Series (estimate purity of map
unit)
• Soil Horizons (typical pedon for soil survey area)
– A
» Depth, texture, color, pH, bulk density,
Ksat…..
– B
» Multiple data elements for each
horizon
– C
Housed in NASIS – National Soil Information
System
Soil Map Unit
Minor
Components
Named
Component

4. Soil and Site Properties
– Observed in the field or measured in the lab
• Sand, silt, clay fractions
• pH
• Organic matter
• Bulk density
• Rock fragment content
• Cation exchange capacity
• Mean annual air temperature
• Flooding frequency
• Slope gradient…
Interpretations
– Suitabilities and Limitations
– Models that use soil property and site data to predict soil behavior under a certain land
use
• Uses outside research to determine which soil characteristics to use
– Septic tank absorption fields
– Vegetation suitability index
– Suitability for excavated ponds
Soil Properties and Interpretations:
Each of these has an
influence on land use,
regardless of what is using
the land, whether reptile,
fungus, bacteria, or human

5. Making this:
Into this:
Soils Reports and
Interpretations:

6. Soil Health Interpretations
Dynamic vs Inherent soil
properties
– Cover crops for grazing
– Tillage radish suitability
– Carbon storage potential
– Earthworm habitat
suitability
– High Tunnel suitability
SOILQUALITY
TIME
Inherent soil quality over time
Soil A
Soil B
SOILQUALITY
TIME
Dynamic soil quality changes
over time
Aggrading
Sustaining
Degrading

7. Creating a Soil Interpretation
Example:
Soil Organic Carbon Storage Potential Rating
1. Define the Activity:
• Soil organic carbon storage potential
identifies soils that contain and are most
suited for accumulation and storage of soil
organic carbon.
2. Separate Aspects:
• Accumulation, Retention, Amount of
carbon already there

8. Soil Organic Carbon Storage Potential Rating
3. Identify Site Features:
– Slope shape
• influences the potential of the soil the gather and retain water as well as collect
organic material through deposition.
– Slope
• influences the potential for runoff and erosion which could remove organic matter.
4. List Soil Properties:
– Depth to a restrictive layer
• influences the overall depth of soil and its potential to store moisture and or perch
water near the soil surface.
– Depth to water table
• influences the inherent nature of the soil to contain saturated conditions near the
soil surface and develop anaerobic conditions during the growing season,
reducing the decomposition rate of organic constituents.
– Moisture regime
• influences the inherent nature of the soil to be moist or dry potentially contributing
to the biologic component of the soil capable of consuming and depleting organic
carbon.
– Percent Sand
• influences the ability of a soil to accumulate carbon
Creating a Soil Interpretation

9. Property
(Criteria)
Potential Carbon Storage Ratings Justification
Very High High Moderate Low
Moisture Regine
(Non-irrigated)
Aquic,
Perudic Udic, Xeric Ustic Aridic
Dry conditions limits soil organic
carbon (SOC) storage
Slope
<1% 1-15% 15-30% >30%
High slopes have higher runoff,
potentially more erosiona dn less
potential to preserve soil organic
carbon
Slope Shape
Concave Linear Linear Convex
Rounded slopes shed water and
limit soil organic carbon storage
Depth to Water
Table <18 cm 18-100 cm 100-200 cm >200Cm
Drier conditions promote
osicdation of soil organic carbon
Depth to
Restrictive Layer
>150 cm 100-150 cm 50-100 cm <50 cm
Shallower soils do not have as
much volume capacity for soil
organic carbon storage
Paticle size -
Sand percent <30% 30-70% >70%
Coarse textured soils generally
hold less soil organic carbon
Property (Criteria) Potential Carbon Storage Ratings Justification
Very High High Moderate Low
Moisture Regine
(Non-irrigated)
Dry conditions limits soil organic carbon
(SOC) storage
Slope
High slopes have higher runoff, potentially
more erosion and less potential to
preserve soil organic carbon
Slope Shape
Rounded slopes shed water and limit soil
organic carbon storage
Depth to Water
Table
Drier conditions promote oxidation of soil
organic carbon
Depth to Restrictive
Layer
Shallower soils do not have as much
volume capacity for soil organic carbon
storage
Paticle size - Sand
percent
Coarse textured soils generally hold less
soil organic carbon

10. 5. Select the number of separations; assign values for each
criteria:
1. Very High Potential - soil, site, and climate have features that are very
highly favorable for organic carbon storage and accumulation.
2. High Potential - soil, site, and climate have features that are highly
favorable for organic carbon storage and accumulation.
3. Moderate Potential - soil, site, and climate have features that are
generally favorable for organic carbon storage and accumulation.
4. Low potential - soil, site, and climate have features that are
unfavorable for organic carbon storage and accumulation.
Creating a Soil Interpretation

11. Property
(Criteria)
Potential Carbon Storage Ratings Justification
Very High High Moderate Low
Moisture Regine
(Non-irrigated)
Aquic,
Perudic Udic, Xeric Ustic Aridic
Dry conditions limits soil organic
carbon (SOC) storage
Slope
<1% 1-15% 15-30% >30%
High slopes have higher runoff,
potentially more erosiona dn less
potential to preserve soil organic
carbon
Slope Shape
Concave Linear Linear Convex
Rounded slopes shed water and
limit soil organic carbon storage
Depth to Water
Table <18 cm 18-100 cm 100-200 cm >200Cm
Drier conditions promote
osicdation of soil organic carbon
Depth to
Restrictive Layer
>150 cm 100-150 cm 50-100 cm <50 cm
Shallower soils do not have as
much volume capacity for soil
organic carbon storage
Paticle size -
Sand percent <30% 30-70% >70%
Coarse textured soils generally
hold less soil organic carbon
Property (Criteria) Potential Carbon Storage Ratings Justification
Very High High Moderate Low
Moisture Regine
(Non-irrigated)
Aquic, Perudic Udic, Xeric Ustic Aridic
Dry conditions limits soil organic carbon
(SOC) storage
Slope <1% 1-15% 15-30% >30%
High slopes have higher runoff, potentially
more erosion and less potential to
preserve soil organic carbon
Slope Shape Concave Linear Linear Convex
Rounded slopes shed water and limit soil
organic carbon storage
Depth to Water
Table
<18 cm 18-100 cm 100-200 cm >200Cm
Drier conditions promote oxidation of soil
organic carbon
Depth to Restrictive
Layer
>150 cm 100-150 cm 50-100 cm <50 cm
Shallower soils do not have as much
volume capacity for soil organic carbon
storage
Paticle size - Sand
percent
<30% 30-70% >70%
Coarse textured soils generally hold less
soil organic carbon

12. *Back up the rating classes with references
Creating a Soil Interpretation

13. 6. Document
Assumptions:
– Soil is undrained,
– adequate nutrients are
available for plant
growth,
– no till management,
– non irrigated
7. Test and Retest
Creating a Soil Interpretation

14. 8. Share it and use it!
SOILQUALITY
TIME
Dynamic soil quality changes
over time
Aggrading
Sustaining
Degrading

15. Science of Interpretations
National Soil Survey Center training (NRCS-NEDC-000288)
– 12 hrs over 4 days
– Regularly held distance learning
– Participants create their own interpretations
May 2017 – special soil health focused training
Another session to be held in the fall of 2017

16. Soil suitability for growing a high biomass
cover crop for grazing purposes
Oats, annual ryegrass, clover mix that is
drilled with a grain drill and planted after
warm-season cash crop

17. Establishment of Tillage Radishes
Provide a suitability map of
areas where tillage radishes
can be established
mechanically and a
reasonable stand can be
accomplished

18. Earthworm Habitat Suitability Index
Suitability potential for beneficial
earthworm habitat in agricultural
cropland areas.
This interpretation is for agricultural cropland where
earthworms are considered beneficial. In forestland,
they can be considered problematic to vegetation and
forest regeneration.
Photo credit: Dwight Kuhn

19. High Tunnel Suitability
Finding the optimal location for a high tunnel system
to maintain or improve soil health by:
– minimizing soil disturbance
– implementing a diverse crop & cover crop rotation
and,
– keeping the soil covered with live crops or cover crops
throughout the year.

20. Next steps
Web Soil Survey Soil
Health Tab
– Fragile Soil Index
– Agricultural
Compaction
• Heavy
equipment
• Livestock
Develop new
interpretations with
cooperation from soil
health community

21. Major Points and Highlights
• Soil Interpretations
• make soil data easier to use (interpret)
• with new research, new soil interpretations can be made from
the existing soil database
• should be specific enough to make them useful
• Soil Health Interpretations
• Model dynamic soil properties – are often ‘potential’ ratings
• With more research, many more can be developed
• Consider taking Science of Interpretations Training
through NSSC (National Soil Survey Center)