George Abawi, Dan Brainard, Dan Clune, Kathryn Duhamel, Beth Gugino, Omololu (John) Idowu, Hilary Mayton, Bianca Moebius, Bob Schindelbeck, Janice Thies, Harold van Es, and David Wolfe

Departments of Crop and Soil Sciences, Horticulture, and Plant Pathology

Soil Health Assessment on New York Vegetable Farms

Aspects of Soil Health

Inherent soil quality Results from natural soil

forming processes and factors

Dynamic soil quality Changes due to human use

and management(Pierce and Larson, 1993)

interaction

Soil Health and Processes

Physical Chemical

Biological

•Nutrient retention and release

• N

• P, K, Ca, Mg, etc.

• micronutrients

• pH

•Energy (C) storage

•Toxicity prevention

•Root proliferation, organismal locomotion

•Aeration

•Water retention

•Water infiltration and transmission; erosion prevention

•Pest suppression

•N mineralization

•OM decomposition

•Habitat protection

How Healthy is a Soil?How Healthy is a Soil?

1.1. How to measure?How to measure?2. Which are meaningful indicators?2. Which are meaningful indicators?3. What are appropriate sampling 3. What are appropriate sampling

protocols?protocols?

Soil Health Indicators

Physical Chemical

Biological

• % OM

• “Active” C, N in OM

• Cation exchange capacity

• N, P, K

• Micronutrients

• [Toxins, pollutants]

• [Glomalin]

• Bulk density

• Penetration resistance

• Aggregate stability

• Water infiltration rate

• Water holding capacity

• Pore size distribution

• Soil disease suppressive capacity

• Beneficial and pathogenic nematodes, [other pathogens]

• N mineralization rate (PMN)

• Decomposition rate• microbial biomass• Respiration rate• Earthworm counts • Genetic diversity

Soil health testing procedures must be:

Rapid Inexpensive Scientifically

meaningful Agronomically

useful

Our Approach:Our Approach:

Research Farm ExperimentsResearch Farm ExperimentsProvide scientific basis from controlled trials to establish useful indicators

Commercial Farm SamplesProvide real-world perspective under range of conditions

~700 SAMPLES WERE ANALYZED FOR MULTIPLE POTENTIAL SOIL HEALTH INDICATORS

Criteria for Selecting Soil Health Indicators

Sensitivity to management Functional relevance Consistency and reproducibility Ease (cost) of sampling Cost of analysis Opportunity to be estimated by

statistical correlation

Field Measurements

PENETRABILITY INFILTRABILITY

LAB MEASUREMEN

TS

DISTURBED SAMPLE

UNDISTURBED SAMPLE

Aggregates: Creating and protecting these crumbs keeps the soil

open to rain and to air exchange.

Methodology: Aggregate Methodology: Aggregate Stability Stability disturbed samplesdisturbed samples

The Cornell Sprinkler 0.5m above

sample aggregates on sieves

Aggregates before stability test

WSAlg 2mm sieve

2-8mm aggregates

WSAsm

0.25mm sieve

0.25-2mm aggregates

1.25cm rainfall in 5 min, providing Energy of

0.142mJ/drop, total of

2.5J/sieve

wetting soil aggregates

Results and Interpretation Results and Interpretation of Aggregate Stability Testof Aggregate Stability Test

% of Soil crumbs stable to 1.25cm rain/5mins:

Organic management ~70% - high

Conventional management ~20% - low

Aggregates after stability test2mm sieves

large pore

intermediatepore

small pore

Aggregate (crumb)

Porosity is important for:• Aeration, permeability, root growth• Water availability• Biological habitat (plant roots and

microorganisms)

Soil Pores

MethodologyMethodologyundisturbed samples – flow through analysisundisturbed samples – flow through analysis

Constant Head

Method

Saturated Hydraulic Conductivity (Ks)

Sand Suction Table at

Ψ = -10kPa (Field

Capacity)

High-Pressure Chamber at

Ψ = -1500kPa (wilting point)

Pore Size Distribution

PenetrationResistance

(PR)

4mm micro-penetrometer

Bulk Density(dried at 105oC)

13 Year Tillage Experiments 13 Year Tillage Experiments

Indicators showing

agricultural management

difference (p<0.05): Plow Till No Till Plow Till No Till

Bulk Density (g cm-3) ns ns 1.21 1.03

Pores > 30µm (%) 13 17 12 16

Pores > 0.1µm (%) ns ns 29 34

AWC (%) 12 16 ns ns

WSAsm (%) 20 41 30 68

Silt Loam Clay Loam

(Aurora) (Willsboro)

Rotation ExperimentRotation Experiment

Indicators showing

agricultural management Corn after Continuous Corn after Continuous

difference (p<0.05): Grass Corn Grass Corn

Bulk Density (g cm-3) 1.31 1.36 ns ns

Pores > 30µm (%) ns ns 10 16

Pores > 0.1µm (%) 42 38 ns ns

AWC (%) 28 23 24 20

WSAlg (%) 34 10 ns ns

WSAsm (%) 40 32 65 33

Loamy Sand Sandy Clay

Comparison of two NY Comparison of two NY Vegetable FarmsVegetable Farms

Hamlin Silt LoamHamlin Silt Loam

Physical Soil Health Indicator: Conventional OrganicAggregate Stability (%) 20 70Total Porosity (%) 45 59Macroporosity (%) 2.8 4.0Bulk Density (g/cc) 1.4 1.2Penetration Resistance (MPa) 1.2 0.8

Management:

Roots can be unhealthy due to...

Poor soil drainage Poor nutrient availability Soil compaction Plant pathogen infection by

Rhizoctonia

Fusarium

Pythium

Thielaviopsis

Etc.

Soil Bioassay w/ Bean for Assessing Soil HealthSoil Bioassay w/ Bean for Assessing Soil Health

Soil collectionSoil collection

Root rot severity rating (1 = healthy to 9 =

primary roots rotted)

Root rot severity rating (1 = healthy to 9 =

primary roots rotted)

Beans grown in greenhouse5 to 6 weeks

Beans grown in greenhouse5 to 6 weeks

Bean roots are washedBean roots are washed

Bean seed planted in field soil

Bean seed planted in field soil

Root Rot Severity RatingRoot Rot Severity Rating

Organic vs Conventional Vegetable Production Systems New York Commercial Vegetable Growers 2004 and 2005

Organic vs Conventional Vegetable Production Systems New York Commercial Vegetable Growers 2004 and 2005

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9

Conventional production

Organic production

Num

ber

of S

ampl

esN

umbe

r of

Sam

ples

Good Moderate Poor

Conventional Organic IPM-present IPM-future

Ro

ot R

ot S

eve

rity

Ra

ting

Ro

ot R

ot S

eve

rity

Ra

ting

Production SystemProduction System

IPM Systems Comparison Site NYSAES, Geneva, NY (C. Petzoldt et al.)IPM Systems Comparison Site NYSAES, Geneva, NY (C. Petzoldt et al.)

aa

b b

c

ab

c

c

1

2

3

4

5

6

7

8

92002

2003

2004

2005

Potentially Mineralizable Nitrogen (PMN)

Indicator for: capacity of soil microbes to convert N tied up in complex organic residues into plant-available forms (ammonium and nitrate)

Technique: Soil is measured for total N, ammonium-N, nitrate-N at sampling and after a 7-day incubation

Interpretation: Positively correlated with %OM, aggregate stability, beneficial nematodes.

Available or “Active” Carbon (C)

Indicator for: Fraction of C and nutrients in total OM that is actually available for soil food web and plants. Shows response to soil mgmt sooner than total OM% changes can be detected.

Technique: Measure C in specific OM fractions separated by wet-sieving (shown in photo), or by a more rapid, cheaper colorimetric technique that oxidizes only “active” C.

Interpretation: Positively correlated with %OM, and with measures of biological activity

Weed Seed Bank Index

Indicator for: Weed seed pressure from common broadleaf species and grasses.

Technique: Still in “research” phase. Composite soil samples are spread in thin layer in small flats and monitored for 4 weeks for number of selected common broadleaf species, grasses, and “other”. A cold treatment may be used to test for weed species requiring vernalization.

Interpretation: Will be primarily useful for tracking a farm over time to see if new practices are effectively reducing the seed bank

Decomposition Rate

Indicator for: capacity of soil microbial community to breakdown crop residue

Technique: Moist, sieved soil placed in petri dish with cellulose filter paper; rate of breakdown monitored weekly by counting grid cells degraded, or by digital imaging.

Interpretation: Positively correlated with %OM (e.g., muck soils have very high rates), and with other measures of soil biological activity.

Effect of Cropping System Effect of Cropping System on Selected Soil Health Indicators (2004)on Selected Soil Health Indicators (2004)

Treatment Crop

Org Matter (%)

N Min Rate (ugN per g soil per wk)

Decomp Rate(% per wk)

Plow Corn Grain 4.0 b 1.48 b 3.0 b

No-Till Corn Grain 5.4 a 1.73 a 9.0 a

Organic Veg/rye 4.5 6.18 17.0

Organic Veg/rye-vetch

4.8 5.78 20.0

Conv Veg/manure

2.32 0.47 3.9

Conv VegAlfalfa

3.06 1.20 10.0

Visible-Near-Infrared Hyperspectral Sensing

?

Timing of Sampling:Timing of Sampling:Does it affectDoes it affect

Indicators Values?Indicators Values?

YES, for most soil quality indicators.Early spring sampling is recommended.

Criteria for Selecting Soil Health Indicators

Sensitivity to management Functional relevance Consistency and reproducibility Ease (cost) of sampling Cost of analysis Opportunity to be estimated by

statistical correlation

Two-Tiered Soil Health Assessment Tier 1:

“Standard” soil health test $40-60 per sample based on disturbed soil samples (with use of

sampling ring) includes in-field penetrometer readings

Tier 2: Based on purpose and site-specific needs Undisturbed soil samples Higher and variable cost, with “a la carte” options

Field Sampling(early spring)

TIER 2:5 cores in rings

TIER 1:10 cores in a bag

TIER 1+2:5*4 penetrations, 3 depths

TIER 1 LAB ANALYSES(prices are tentative)

Physical ($15)/Sample Biological ($15-35)/Sample

Chemical ($10)/Sample

Bulk density (Composite 6 cores in a plastic bag)

Water Stable Aggregates (2 -0.25 mm)

Available Water Capacity (by measurement and estimation)

Textural class (by feel)

Field Penetration Resistance

Potentially Mineralizable Nitrogen ($10)

Active Carbon ($5)

Root Rot Assay ($15)

Weed assay (under development, $5)

Standard Chemical Test ($10)

VNIR reflectance

TIER 2 LAB ANALYSES(prices are tentative)

Physical ($45)/4 Cores Biological (up to $90) Chemical ($10+?)

Macro-, meso-, and micro-pores

Penetration resistance

Water stable aggregates

Textural class

Field penetration resistance

PMN ($10)

Active Carbon ($5)

Root Assay ($15)

Weed Bioassay (under dev, $5)

Nematode Assessment ($25)

Microbial Biomass ($20)

Respiration Rate ($10)

Field Earthworm Counts

Standard Chemical Test ($10)

Large selection of other a la carte analyses

VNIR reflectance

High Quality Soil (physical and biological)

Date: 2-8-06

INDICATORS Measured ValuesAverage

Rela RATING CONSTRAINTSCONSTRAINT

Sub-optimal

50th Pecentile

Optimal

Root Rot Rating 3.50 1

Potentially Mineralizable Nitrogen 24.27 2

Organic Matter (%) 4.21 1

Aggregate Stability 0.25 - 2mm (%) 50.50 2

Bulk Density (g/cc) 1.04 2

Available Water Capacity (m/m) 0.16 1

9F

Depth Value (Psi) Rating Symptom

0-6 inches 120 Low - Excellent

6-12 inches 160 Medium - Good

12-18 inches 200 Medium - Good

Sandy SoilsSoil Quality Rating Model by Cornell Soil Health Team

OVERALL QUALITY

Farm: Bob Fresh Veggies Field: East BarnSoil Type: Sandy Loam

Soil Texture: Sand Drainage: Good Percentile

Slope (%): 1%

out of 12 ( Low:0-4; Medium:5-8; High:9-12)

FIELD PENETROMETER ASSESSMENT

0 - Low; 1 -Medium; 2 -High

Medium Quality Soil (physical and biological)

Date: 2-8-06

INDICATORS Measured ValuesAverage

Rela RATING CONSTRAINTSCONSTRAINT

Sub-optimal

50th Pecentile

Optimal

Root Rot Rating 4.13 1

Potentially Mineralizable Nitrogen 1.20 0

Nitrogen Release and Microbial Activity

Organic Matter (%) 3.06 1

Aggregate Stability 0.25 - 2mm (%) 15.79 0

Water Intake and Transmission

Bulk Density (g/cc) 1.28 1

Available Water Capacity (m/m) 0.17 2

5F

Depth Value (Psi) Rating Symptom

0-6 inches 210 Medium - Good

6-12 inches 270 Medium - Good

12-18 inches 370 High - Bad Deep Compaction

Sandy SoilsSoil Quality Rating Model by Cornell Soil Health Team

OVERALL QUALITY

Farm: Bob Fresh Veggies Field: West BarnSoil Type: Sandy Loam

Soil Texture: Sand Drainage: Good Percentile

Slope (%): 1%

out of 12 ( Low:0-4; Medium:5-8; High:9-12)

FIELD PENETROMETER ASSESSMENT

0 - Low; 1 -Medium; 2 -High

Low Quality Soil (physical and biological)

Date: 2-8-06

INDICATORS Measured ValuesAverage

Rela RATING CONSTRAINTSCONSTRAINT

Sub-optimal

50th Pecentile

Optimal

Root Rot Rating 6.38 0Root Health

Potentially Mineralizable Nitrogen 5.68 1

Organic Matter (%) 3.73 1

Aggregate Stability 0.25 - 2mm (%) 31.56 1

Bulk Density (g/cc) 1.59 0

Root Proliferation, Hardsetting and

Crusting

Available Water Capacity (m/m) 0.13 0

Water storage

3F

Depth Value (Psi) Rating Symptom

0-6 inches 320 High - Bad Surface Compaction

6-12 inches 360 High - Bad Subsurface Pan

12-18 inches 400 High - Bad Deep Compaction

Sandy SoilsSoil Quality Rating Model by Cornell Soil Health Team

OVERALL QUALITY

Farm: Bob Fresh Veggies Field: North BarnSoil Type: Sandy Loam

Soil Texture: Sand Drainage: Good Percentile

Slope (%): 1%

out of 12 ( Low:0-4; Medium:5-8; High:9-12)

FIELD PENETROMETER ASSESSMENT

0 - Low; 1 -Medium; 2 -High

Linking Indicators to Constraints

ROOT ROT RATING: SUSCEPTIBILITY TO ROOT DISEASES

ACTIVE CARBON: ENERGY STORAGE, ABILITY TO SUPPORT SOIL ORGANISMS

POTENTIALLY MINERALIZABLE NITROGEN: ABILITY TO SUPPLY NITROGEN

AGGREGATE STABILITY: WATER INFILTRATION AND TRANSMISSION; PREVENTION OF RUNOFF AND EROSION; RESISTANCE TO HARDSETTING AND CRUSTING, AERATION

BULK DENSITY: AERATION, ROOT PROLIFERATION, ORGANISM MOBILITY

AVAILABLE WATER CAPACITY: WATER STORAGE AND RELEASE

PENETROMETER READINGS: SHALLOW AND DEEP ROOT PROLIFERATION, DRAINAGE

Linking Indicators to Management

HIGH ROOT ROT RATING: proper rotation, cover crops

LOW ACTIVE CARBON: cover crops, sod rotation crops, manure, compost

LOW POTENTIALLY MINERALIZABLE NITROGEN: add OM, leguminous cover/rotation crops

LOW AGGREGATE STABILITY: reduce tillage, shallow-rooted cover/sod crops, manure

HIGH BULK DENSITY: add OM through cover crops, perennial sod crops, manure, compost; limited soil loosening

LOW AVAILABLE WATER CAPACITY: add stable OM (compost); reduce tillage

HIGH PENETROMETER READINGS: deep tillage/zone building, deep-rooted cover crops

What’s Next?

Develop service lab infrastructure Expand into Northeast Region (NE

SARE) Further test methodologies (incl.

VNIR) Further develop database Link soil health to soil “value”

Funding

Northern New York Agricultural Development Program

USDA Northeast Sustainable Agriculture Research and Extension Program (SARE)