Soil Health a Practical Approach to Farming

in the 21st Century

David Lamm National Soil Health & Sustainability Team, Leader

Why in 2013?

• World population is estimated to be at 9.1 billion by 2050 • To sustain this level of growth, food production will need to rise by 70 percent • Between 1982-2007, 14 million acres of prime

farmland in the U.S. was lost to development • Energy demands

– Increase use of biofuels (40% of corn used for ethanol) – Increase use of fertilizer (use of Anhydrous up 48%, Urea

up 93%)

Soil Health: What is It?

The continued capacity of the soil to function as a vital living ecosystem that sustains plants, animals, and humans

Soil Function to Support Agriculture

• Nutrient cycling • Water (infiltration & availability) • Filtering and Buffering • Physical Stability and Support • Habitat for Biodiversity

Soil is a Living Factory

• Macroscopic and microscopic organisms – Food – Water – Shelter – Habitat – Powered by

sunlight

• Management activities improve or degrade soil health – Tillage – Fertilizer – Pesticides – Grazing – Plant Diversity

Clear runoff from no-till f ld

No-till field

Conventional-till field

Sediment runoff from conventional-till field

Is the Buffer working? 6 /2007

Gabe Brown -ND

Ray McCormick -IN

Dave Brandt -OH

Brandon Rockey -CO Ray Styer -NC

Ecology: the study of

relationships between people, animals, and

plants, and their environment.

Interconnectedness

Soil Surface

NPK & C

Ray Archuleta

Farm or

Ranch

Characteristics of a Stable Ecosystem

Farm or Ranch Steady

State

Disrupted Soil Ecosystem

This soil is naked, hungry, thirsty and running a fever! Ray Archuleta 2007

The Battle is Won or Lost Here

Agricultural soils do not have a water erosion/runoff problem, they have a water infiltration problem.

Soil Health Planning Principles

• Manage more by Disturbing Soil Less • Use Plant Diversity to Increase Diversity in

the Soil • Grow Living Roots Throughout the year • Keep the Soil Covered as Much as Possible

Manage More by Disturbing the Soil Less

Loss of SOM as CO2

• Agricultural Disturbance Destroys “Soil Organic Matter”

• Destroy “Habitat” for Soil Organisms

• Creates a “Hostile” Environment

• Types of Disturbance – Physical (tillage) – Chemical (over application) – Biological (over grazing)

Forest SOM = 4.3 %

CT 17 yr- Soybean monoculture SOM = 1.6 %

20 c

m la

yer

Same Soils: Dynamic Soil Properties Changed!

62.8% loss of SOM after

17 yr intensive

tillage

Reicosky et al., 1995

Where the problem?

Biological Disturbance • Overgrazing • Mono-culture pasture

1. Disturbance stimulates weed (first responders)

2. Increases weed population 3. Diminishes Fungal biomass and spores- 4. Reduces infiltration 5. Increases soil temperature

6. Diminishes the habitat of the soil microbes

7. Increases the necessity for synthetic inputs

Biological Disturbance Impacts of Overgrazing

Chemical disturbances: over-application of pesticides, fertilizers and manures

Impact of Pesticides on Soil Health

• Impacts non-target organisms – not well understood – Fungicide takes out mycorrhizal fungi

• Pesticides simplify, not diversify • May restrict crop rotation • May restrict cover crop diversity

Impact of Fertilizer on Soil Health

• Short-circuits the rhizosphere & P cycle • Depresses activity of natural N fixers • Stimulates bacterial decomposition of SOM • Excess N at risk for leaching or denitrification • Increased soil salinity (Synthetic fertilizers are

salts)

Impact of Manure on Soil Health

• Can add organic matter and carbon • Build up of P to excessive levels

– Greater than 100 ppm discourages plants from feeding mycorrhizal fungi

• Other issues – Heavy metals – Salts – Pathogens – Soil compaction from application/incorporation

Cover Crop

No Till

NRCS Practices that address soil disturbance

• Nutrient Management

• Pest Management • Prescribed Grazing

Increasing Diversity in a Crop Rotation

• Growing more plants in the same rotation period – Increase soil organic matter – Breaks pest cycles – Improves nutrient availability

• Provide windows for management – spread manure – Increasing diversity in soil organisms

Use Plant Diversity to Increase Diversity in the Soil Microbes

• Plants interact with microbes – Trade sugar, carbohydrates & proteins from roots for

nutrients (Exudates) – Each plant has a unique “exudate” that attract a

specific group of soil microbes – Microbes convert plant material to OM

• Requires a diversity of plant carbohydrates to support the variety of microbes

• Lack of plant diversity will drive system to favor some microbes more than others – Disturb soils are dominated by bacteria – Created the habitat for them to flourish

Biodiversity Key to Success • Lack severely limits any

cropping system • A diverse and fully

functioning system provides nutrients, energy and water

• Diversity above ground equals diversity below ground

Mimic Native Ecosystem

• Plant growth habit – Cool season – Warm season

• Plant Morphology • Broad leaf • Grass

Prairie

Forest

Crop Classification Warm Season Grasses

• Corn • Millet • Sudan

• Sudex • Sorghum

Broadleaf • Alfalfa • Soybean • Buckwheat

• Chick pea • Cow pea • Sunflower

Crop Classification Cool Season Grasses • Barley • Rye

• Triticale • Wheat

Broadleaf • Canola • Clovers • Mustards

• Pea • Radish • Turnips

Role of Diversity

1. Allow you to look at cropping periods rather than years

2. Can be used to accelerate rejuvenating soil health

3. Getting 4 to 6 weeks of growth is adequate to get the “rotation” effect!

4. Will increase soil biological diversity “Diversity above= diversity below”

NRCS Practices that address Diversity

Conservation Crop Rotation

Cover Crop

NRCS Buffer Practices to Improve Diversity

Contour Buffer Strip

Cross Wind Trap Strips

Riparian Herbaceous Buffer

Field Border Filter Strip

Hedgerow

Field Border

Grow Living Roots Throughout the Year

• Increases microbial activity influences the N mineralization and immobilization

• Increases plant nutrient/vitamin uptake/ concentrations with mychorrhizal and bacteria associations

• Increases biodiversity and biomass of soil organisms • Improves physical, chemical and biological properties

of soils • Sequesters and redeposit nutrients • Increases OM

Root Mass in Top 4” of Soil

0

500

1000

1500

2000

2500

1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec

Lbs.

/ac.

Rye & HairyVetch CoverCrop

Corn Grain

Soybean 7" rows

How to Keep a Living Root All Year Long?

• Lengthen Rotation – Add Wheat or another crop to rotation

• Select Shorter Season Varieties – Choose 100 -104 day – Only need 6 - 8 weeks to provide benefit

• Interseed into Growing Crops – Planting cover crop before harvesting of cash crop

Hairy vetch planted into corn July 17

Hairy vetch planted into bean June 29

Hairy vetch good fall growth

Photos 29 Oct 2003

Fall Biomass Data

• Lose 50% to 80% of fall growth potential with a 1 month planting delay • Later planting defers growth potential to spring • Rye is the least impacted by a later planting date

Dry Matter of Both Planting Dates Measured in November

0

1000

2000

3000

4000

5000

6000

7000

8000

Oat

s

Rad

ish+

Oat

s+A

WP

Oat

s+C

rimC

love

r

Oat

s+R

adis

h

Vet

ch+O

ats

Rad

ish

Rye

+Rad

ish

Rye

gras

s

Rye

gras

s+C

rimC

love

r

Whe

at

Rye

gras

s+A

WP

Triti

cale

Vet

ch+R

ye

Rye

Red

Clo

ver

lbs/

acre

Late Aug PlantingLate Sept Planting

0

1000

2000

3000

4000

5000

6000

7000

8000

Rye

Vet

ch+R

ye

Triti

cale

Rye

+Rad

ish

Whe

at

Rye

gras

s

Rye

gras

s+A

WP

Rye

gras

s+C

rimC

love

r

Vet

ch+O

ats

Red

Clo

ver

Rad

ish+

Oat

s+A

WP

Late Aug plantingLate Sept planting

Dry

Mat

ter (

lbs/

ac)

Cover Crop Biomass in April/May 2010

Spring Biomass Data Rye and triticale containing mixtures were least impacted by a later planting date

Ryegrass containing mixtures were moderately impacted by a later planting date

Legumes w/ no spring growing companions were heavily impacted by a later planting date

What are farmers doing!

Interseeding Annual Ryegrass

Cover Crop

Corn Silage

Field Corn

Standing Soybeans

Keep it Covered as Much as Possible

• Control Erosion • Protect Soil Aggregates • Suppresses Weeds • Conserves Moisture • Cools the Soil • Provides Habitat for Soil Organisms

Soil Temperatures

When soil temperature reaches 140 F Soil bacteria die

130 F 100% moisture is lost through evaporation and transpiration 113 F

Some bacteria species start dying 100 F 15% moisture is used for growth 85% moisture lost through 95 F evaporation and transpiration

70 F 100% moisture is used for growth

J.J. McEntire, WUC, USDA SCS, Kernville TX, 3-58 4-R-12198. 1956

Soil Organic Matter & Available Water Capacity

Percent SOM Sand Silt Loam Silty Clay Loam

1 1.0 1.9 1.4

2 1.4 2.4 1.8

3 1.7 2.9 2.2

4 2.1 3.5 2.6

5 2.5 4.0 3.0

Berman Hudson Journal Soil and Water Conservation 49(2) 189 194 189- March April 1994 – Summarized by: Dr. Mark Liebig, ARS, Mandan, ND Hal Weiser, Soil Scientist, NRCS, Bismarck, ND

Inches of Water/One Foot of Soil 1 acre inch = 29,000 gallons of water

Soil Organic Matter Characteristics

• Density of SOM: 0.6 g/cm3 vs. 1.45 g/cm3 soil Bulk density =Mass (grams)/Volume (cm3)

• SOM has less density than soil so it has more space for air and water storage.

• Every Pound SOM holds 18-20# of Water! • SOM acts like a Sponge!

• 1.0% OM = – 10,000 lbs Carbon – 1,000 lbs Nitrogen – 100 lbs Phosphorous – 100 lbs of Sulfur.

• Mineralization Rate = 2-3% from Organic N to Inorganic N.

• Resulting in 20 to 30 lbs of useable N per acre.

Soil Organic Matter Nutrient Bank Account.

NRCS Practices that Keep Cover on the Surface

• No Till • Residue Management

Soil Health Planning Principles

• Manage more by Disturbing Soil Less • Diversify with Crop Diversity • Grow Living Roots Throughout the

year • Keep the Soil Covered as Much as

Possible

Soil Health Management Systems

• Collection of conservation practices that focus on maintaining or enhancing soil health

• Utilizes existing NRCS conservation practices • Incorporates the “4” soil health planning

principles • Must be implemented as a system • Farming enterprise specific

NRCS Conservation Practice Standard

• 161 different practice standards – 97 CED has lead – 21 ESD Agronomist has lead

• 13 Erosion primary resource concern • 4 Residue Management

– 9 ESD Grazing Specialist has lead • Limited number of practices to choose from • Soil Health requires more than controlling

erosion

Conservation Practices

• Must Do – Key practices that achieve the greatest

impact on soil health – Address the “4” planning principles – Cropping system specific – synergistic affect is what give the largest

return

Must Do

• Conservation Crop Rotation

• Cover Crop • No-Till System • Nutrient

Management • Pest Management

As Applicable

• Practices that address resource concerns that may not occur on all fields

• Sight specific – Irrigation water management – Buffer practices

Best Accepted New Technology

• Conservation activities that might not be in an NRCS conservation practice standard

• Improve soil health • Controlled traffic

pattern • Precision application

of nutrients and pesticides

• Use of floatation tires

Helping People Help the Land

Controlled Traffic Farming

Adjusting all farm equipment so that the same wheel tracks are used for different field operations year after year

This limits compaction to only the wheel tracks.

Soil Health Management System Templates

• Cropping system specific –Midwest –Northern Plains –Southeast –Southwest –Organic