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)

103 103

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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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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