Post on 24-Feb-2016
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Soil and Ecosystem Dynamics in Soil Survey
NRCS
Susan Andrews, Ph.D. EcologyNRSC NSSC National LeaderSoil Quality and Ecosystems
June 17, 2013
Three Main Areas of Responsibility:
Soil Quality (SQ) Dynamic Soil Properties (DSPs) Ecological Sites (ESs)
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103
103250
1. Soil Quality in Soil Survey NRCS Soil Health
Initiative SQEB has
technical development responsibility
Emphasis on decision support and assessment tools
Soil Quality Definitions
“fitness for use”- Larson & Pierce, 1991
“capacity of the soil to function”
- Karlen et al. 1997
reflects natural characteristics based on soil forming factors
climate, parent material, topography, and biota, all acting over time – Jenny, 1941
INHERENT SOIL QUALITY
DYNAMIC SOIL QUALITY
- after Pierce and Larson, 1993
describes status or condition of soil result of land use or management
practice
Kinds of Soil Quality
Relative Assessment
Soil A Soil B
Soil
Func
tion
Inherent SQDynamic SQ
50%85%
Dynamic SQ with respect to Inherent capability
- After Andrews et al., 2004
Soil Health v. Soil Quality Soil health is used as a synonym
for soil quality - Doran and Parkin, 1996
Minor exceptions: Health often includes only dynamic
quality Health some greater emphasis on
biology A soil may have poor inherent soil quality but still have good soil health.
- Gregorich and Carter, 1997
Improvement of Kits and GuidesWORKSHEET 2: SOIL MANAGEMENT PRIORITIES Please select the soil function of primary importance to you in your system. This is your soil quality management priority. If you do not have a clear preference follow default instructions below. SOIL FUNCTIONS (Place an “X” by your priority function)
___ crop productivity & nutrient relations - the ability to produce plants of economic importance (implies adequate water storage, efficient cycling of nutrients, maximizing retention and plant availability, site stability, and filtering of toxics) ___ water relations & structural stability - partitioning and storage of water and solutions to maximize deep percolation for ground water recharge withstand erosive forces, and to provide a medium for plant root growth ___ health and habitat - the ability to provide the necessary conditions to support a variety of unstressed plants and animals; support biodiversity ___ filtering and buffering - an ecosystem service in which toxic or hazardous compounds are degraded or reduced in their availability to plants and animals INDICATOR CHOICE BY MANAGEMENT PRIORITY Indicator tests to use for analyzing the soil’s ability to perfom specific soil functions -Arid & Subhumid Regions
Indicator Productivity Water Habitat. Filtering
respiration X X
infiltration X X X
bulk density X X
electrical cond. X X X
pH X X X
nitrate leaching X
aggregates X X X X
slaking X X
earthworms X X X
WFPS X
H2O NO3 X X
H2O EC X
Tool to assess soil health, by: Selecting simple indicators Interpreting results
Based on function WRT inherent soil properties
Providing basic management advice Part of the CDSI Mobile Planner Will beta-test MS Access version
Soil Health RAT
Soil Quality Priorities Develop tools and interpretations
Revision of test kits and guides Identify and interpret effects of soil function
Simple tools for conservation planning (RAT)
Advise the Soil Health Management Initiative
Inform trainers & others of the latest science
Inform farm bill policy
An inventory of soil change over the human time scale,
due to: - human management
- natural disturbance
-Richter and Markowitz, 2001
Millennia
Centuries
Decades
Decades and less - the management time scale
Decades to centuries - the recovery time scale
-Tugel et al., 2005
2. Dynamic Soil Properties in SS
Improve Accuracy of SS Databases
(and provide reference values for SQ indicators)
Soil Database estimate
Grassland-
measured
Cultivated-
measuredAksarben
2-4 % 6.0 3.0
Monona 2-4 % 3.6 2.9 Important for C-sequestration, water holding
capacity, agg. stability, pesticide applications, nutrient applications
Soil organic matter
(Grossman, unpublished)
Develop Interpretations of Management Effects on Soil
Function The importance of
soil change is its affect on function.
The consequences of change depend on its reversibility. (Arnold et al.,1990)
Productivity
Land degradation
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103250
Land use impacts
Differences in Resistance and ResilienceSo
il Fu
nctio
n
Time (years)Compaction
Disturbance
Soil withhigh resistance
Soil with low resistanceand high resilience
-Seybold et al., 1999
Soil with low resistanceand low resilience
Main DSP Priorities Identify best ways to inform
conservation Develop new methodologies to
rapidly populate the database Models and pedotransfer functions Validation sampling design
Hire postdoc for data mining and modeling
Sampling, assessment & analyses training
Standards and database requirements
3. Ecological Sites in Soil Survey
Partnership with S&T Ecological Sciences Division and National Grazinglands Team
New standards follow basic MLRA planning
Soil Survey offers procedures for control and assurance and the correlation process
To succeed, we (NCSS) must work in interdisciplinary teams
Ecological Site DefinitionAn ecological site is a distinctive kind of land based on: • recurring soil, landform, geological, and
climatic characteristics that differs from other kinds of land
• in its ability to produce distinctive kinds and amounts of vegetation, and
• in its ability to respond similarly to management actions and natural disturbances.
State-and-Transition DefinitionsSTATE - a recognizable, resistant and resilient complex of two ecosystem components: the soil base and the vegetation structure
- Soils help determine the site’s capabilities- The interaction between soil and vegetation determines the
functional status of the site and it’s inherent resistance to change.
Stringham, et al., 2003Time
Vege
tatio
n att
ribut
e(s) “Steady
” States
TRANSITION - the trajectory of a change - change is precipitated by natural events, management
actions, or both- degrades the integrity of one or more of the state’s
primary ecological processes beyond the point of self-repairTHRESHOLD – boundary in space and time between two
states- irreversible for practical purposes
Time
Vege
tatio
n att
ribut
e(s) thresholds
transitions
State-and-Transition Definitions
Post oak/blackjack oak/little bluestem
ESD, Missouri
Hot summer burn and /or long-term grazingBurn, Site prep &
Planting / Seeding.No grazing or
limited controlled grazingPost oak/flowering
dogwood/ tick trefoil-goldenrod. Multi-story. Canopy: 30-90%
Post oak/buckbrush (or similar) Lacks mid-story. Understory single species woody dominatedCanopy: open 30-90%
Pasture (improved)Non-native grass sod
Abandonment for 20+ yr
with recruitment of woody natives
Harvest, site prep, seeding
Westoby, et. al., 1989Stringham et.al., 2001
State-and-Transition Model
Working Definition of a Agroecological Site
An agroecological site is a subset of an Ecological Site (ES) based on: • recurring soil, landform, geological, and
climatic characteristics that differs from other kinds of land (within one ES)
• in its potential to support distinctive ranges of soil functions (as indicated by dynamic soil properties), and
• in its ability to respond similarly to management actions and natural disturbances.
Low
Degradation / Resilience Threshold
Resource Concern / Function Threshold
Soil
Func
tions
/ Ec
osys
tem
Ser
vice
sHigh
Attainable for Grain Rotations Production Group
Nativ
e / N
atur
alize
d
P
lant
Com
mun
ities
Grai
n Ro
tatio
n
Agricultural Production Groupswithin an Agroecological Site
Fora
ge C
rops
Root
Cr
ops
Vege
tabl
e Ro
tatio
n
Ecological Potential
Attainable for Forage Crops Production Group
Native/Naturalized States
Land Management Optimization (LMO) Model
Degradation / Resilience Threshold
Resource Concern Threshold
Soil
Func
tions
/ Ec
osys
tem
Ser
vice
s
Disturbance within one Agricultural Production Group
Ecological Potential
Attainable for Grain Rotations Production Group
Gra
in
Rota
tion
s
Rotation, low-till,
no cover crops
Organic system w/
cover crops
Monocrop, Deep tillage
Continuous no-till w/
cover crops
Diverse rotation,
tillage
Land Management Optimization
for one Production Group
Main ES Projects and Priorities
ES Policy and Standards (final revisions)
Database Requirements (review stage)
ES for Additional Land Uses Crop (pilot stage) & pasture (planning
stage) Riparian (review stage) Wetlands, Subaqueous (new, some
work) Development of Hierarchical
Classification Training, Communications and
Outreach
Comments and Questions?
Contact:susan.andrews@lin.usda.g
ov