Soil health: Impact of tillage, carbon, soil quality, and ... · tillage, carbon, soil quality and biodiversity MORRIS ... We depend on soil for our food supplies and many ... No.

Don Reicosky,

(Soil Scientist, Emeritus)

by

Soil Health: impact of tillage, carbon, soil quality

and biodiversity

MORRIS

"SOILS LAB"

* USDA-ARS-MWA

North Central Soil

Conservation Research

Laboratory Morris, MN

USA

Agricultural

Research

Service

[email protected]

Chippewa Watershed: Sustainable

Agriculture and Soil Health Workshop Mar. 27, 2014

It’s all about

“C” management!

Food Security

(Sustainability)

(mostly)

Activity: Education

Project/Program,

Restoration/

Conservation Project,

Volunteer Monitoring

Description: We

seek to improve

water quality

through increasing

awareness and

engaging the public

around watershed

issues while

promoting a healthy

agricultural,

industrial and

recreation based

economy for the

region

Chippewa Watershed Project

Carbon sequestration involves removing carbon from the

atmosphere via photosynthesis and storing it in different

components of terrestrial or aquatic ecosystems. Carbon

sequestration is enhanced by agricultural systems that

utilize conservation agriculture, incorporate cover crops,

rotate crops, add organic amendments, manage nutrients

efficiently, restore degraded soil, and convert land to

native vegetation or install permanently vegetated

conservation buffers. These practices improve soil

quality and increase soil organic matter, which in turn

increase water retention, reduce drought risk, improve

fertility, reduce erosion and protect water quality.

Soil Carbon Sequestration

and Water Quality

We depend on soil for our food supplies and many

other vital functions including water management.

There is pressure on our earth

resources and food security!

1,440,000,000

ha cropland (3.56 billion acres)

9,000,000,000

people by 2050

OUR HUNGRY WORLD

OUR THREATENED PLANET

OUR CHILDREN’S FUTURE

OUR ONE CHANCE… Conservation Agriculture

All rest on “OUR LIVING SOIL” that depends on

soil organic carbon!

C

The “key” component is:

Food Security

Soil Organic Carbon

3 Keys to Conservation Agriculture!

1 Minimal soil

disturbance

2 Continuous

residue cover

3 Diverse rotations

or synergy crops

Soil Organic Carbon

C

Photosynthesis

Energy

Capture

The Carbon Cycle

Respiration

Energy

Release

+

+

The devil is

in the

details! Beckism #101

Plants are the

main source of

our food/energy

generation.

C

C

C C

C

C

C

C C

C

C

C

C C C

C C

C

C

C C

C C C

C C

C C C

C C

C

C C C

C C

C C C

C

C

C

C C C

C C

C

C

C C

C C

C

C

C

C

C

C

C

C

C

C

C

C

C

C C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C C

C

C

C

C

C

C

C

C

C

C

C C C

C C

Plant Power

Carbon capture

Carbon storage

Energy storage

Food source

Energy source

Soil carbon input

Environmental

benefits

Quality of Life

View the plant as carbon! (~ 45% C)

Carbon is the “C” that starts

“C”onservation!

C

Conservation is more about plant management than soil

management because of the importance of carbon.

Food

Feed

Fuel

Fiber

C

Sun

Soil

Air Water

Ou

r R

es

ou

rces

Ecosystem Services

Nature’s Interdependent Tri-Cycles:

Water, Carbon, Nitrogen,

H2O C N

Tillage

Layer

Tillage disrupts the natural cycles!

H2O

Carbon is our greatest water management tool.

C

C Increases: infiltration, transpiration, soil tilth, soil

structure, available water holding

capacity, water use efficiency, water

storage, root depth,soil biological

activity, water quality, root and worm

bio-pores, aeration, nutrient cycling,

drainage

C Decreases: Soil runoff, erosion, evaporation,

sediments, temperature, crusting,

pollution, compaction, desertification,

“C” = live and dead plant

leaves, stems, roots, biomass,

residue, mulch layer, POM, SOM,

manure, humus and humic acids.

Residue

covered soil Bare soil

Year

2007

2008

Yield

(Mg/ha)

12.4

197 bu/ac

11.7

186 bu/ac

Yield

(Mg/ha)

10.8

172 bu/ac

10.6

169 bu/ac

65 to 100

2.6-3.9 in

60

2.4 in

(mm)

van Donk SJ, Martin DL, Irmak S, et al. 2010. Crop residue cover effects on

evaporation, soil water content, and yield of deficit-irrigated corn in west-central

Nebraska. T ASABE 53(6):1787–97.

Residue

- Bare

Yield

(Mg/ha)

1.6

25 bu/ac

1.1

18 bu/ac

Water req.

Surface mulch decreases soil evaporation.

Tillage-induced

Carbon Dioxide Loss

CO2CO2

No. 1 Environmental Enemy

in Production Agriculture

M = Mobile

R. = Research

G = Gas

E = Exchange

M = Machine

MR. GEM

Invisible effects of invisible forces!

Tillage Type

MP SS MK YK RM NT0

40

80

120

160

MP SS MK YK RM NT

Cu

m.

CO

2 L

os

s (

g C

O2 m

-2)

0

20

40

60

80

5 hours after tillage 24 hours after tillage

59.8

31.7

11.5

4.7 3.41.4

159.7

66.2

26.7

19.415.4

7.2

y = 0.0792x + 9.7647

R2 = 0.9698

0

30

60

90

120

150

180

0 250 500 750 1000 1250 1500 1750 2000

Cross Sectional Area Loosened Soil (cm2)

CE

R (

g C

O2 m

-2)

MP

SS

RM

MK

NT L128

Strip Tillage #1 3 June 1997 Swan Lake

Cumulative Carbon Dioxide Loss after 24 hours

Not Tilled

4 in.

100 mm

6 in.

152 mm

8 in.

203 mm

11 in.

280 mm

Soil Surface

1998 Plow Depth Study Swan Lake Farm

4 in.

100 mm

6 in.

152 mm 8 in.

203 mm 11 in.

280 mm

Not Tilled Soil Surface

12 Aug., 1998 Plow Depth Study Swan Lake Farm

24 hour cumulative CO2 losses (g CO2 m-2)

48

10

105

202 229

What do large “no-till”

seeders due to CO2 emissions?

Previous work showed tillage-

induced CO2 emissions were

proportional to soil volume

disturbed.

Low disturbance drill High disturbance drill

Comparison of No-Till Drills

Low disturbance drill Non

disturbed High disturbance drill

Disc Harrow Moldboard Plow

CO2 & H2O loss from Low vs High Disturbance Drills

0.38 0.35

3.01

0

1

2

3

4

5

None Low High

Disturbance Type

CO

2 l

os

s (

gC

O2

/m2

/h)

CO2 loss

Evaporation

0

0

0.2

0.4

0.6

0.8

1.0

Ev

ap

ora

tio

n (

mm

/h)

0.70

0.17

0.35

There’s a jungle full of life living

in your belly button!

There’s a jungle full of life living

in your soil!

Your belly button is crawling with billions

of bacteria, in all shapes, sizes and

appetites.

It’s warm, dark and moist, a perfect home

for bacteria.

The tiny bacteria in the “jungle of

microbial diversity” are generally

harmless.

Everybody’s bellybutton carries a

different cast of characters.

Minneapolis Star Tribune, 12/7/2012.

Jiri Huler, Lead scientist, NCSU

Your soil is crawling with billions of

critters (bacteria, fungi, arthropods,

nematodes, worms, and animals) in all

shapes, sizes and appetites.

The temperature is variable, it’s dark and

moist, a perfect home for soil biology.

The tiny critters in the “jungle of

microbial diversity” are generally

harmless.

Everybody’s soil carries a different cast

of characters.

What’s in your belly button? What’s in your soil?

The bellybutton project is

out to “educate the public

about the role of bacteria

play in our world. Bacteria

are always present on our

skin and in our bodies.”

5% OF SOIL ORGANIC MATTER IS LIVING ORGANISMS

http://www.rw.ttu.edu/2302_butler/chapter6.htm

Mammals - gophers, moles, mice, groundhogs

Earthworms - night crawlers, garden worms

Insects and mollusks - ants, beetles, centipedes, snails,

slugs

Microfauna - nematodes, protozoa, rotifers≈

Microflora - fungi, yeast, molds, mychorhiza

Actinomycetes - smaller than fungi, act like bacteria

Bacteria - autotrophs, heterotrophs, rhizobia, nitrobacter

Algae - green, blue-green

The “living soil”, a biological system.

≈

“That soil fauna and microbial action

is the equivalent of grazing two

African elephants per acre.”

Source: Jerry Hatfield, the director of USDA’s National Laboratory for Agriculture

and the Environment in Ames, Iowa.

A healthy population of earthworms will construct 3178 km of small

burrows and 1192 km of pencil thick burrows in a hectare of soil.

Earthworms will move tons of nutrients and soil on each hectare

every year and are our natural soil mixers.

Source: http://davidkusel.com/farm/nightcrawler1.htm

Nightcrawler's compost

pile called a midden

O

O

O

O

O

Earthworms are “nature’s” plow (and a lot more!)

Before

Primary

Tillage

After

Primary

Tillage

After

Secondary

Tillage

CO2 loss CO2 loss

Intensive tillage “butchers the biology” in

the soil. It cuts, slices, and dices the soil

and blend’s, mixes, and inverts the soil

creating havoc for the soil biology (fauna).

The soil is a natural living system that contains a lot of life and

when tilled intensively is dramatically changed. It can be

considered analogous to human reaction to a combination of:

earthquake

forest fire tsunami

tornado hurricane

all rolled into one perturbation event!

asteroid

impact

Tillage is a biotic disturbance!

“Turmoil of Tillage”

Intensive soil tillage opens the “all you can

eat buffet” for the birds and microbes.

Earthworms are allergic to cold steel! Mike Bell

Tillage creates twin problems:

-- Accelerated soil degradation

-- Accelerated soil erosion

Soil organic matter acts like a “sponge” for

water retention and release to plants.

Soil high in carbon is rich in

“spongy organic matter” that

releases nutrients to crops and

holds more than its own weight in

water.

SOM “sponge” sponge

C

Available water capacity (AWC) is analogous to a

bucket. The larger the “bucket”, the more water

stored available to the plants.

Source: Dept. of Agriculture Bulletin 462, 1960

AWC = textural

water + SOM “sponge”

water

Sand, silt, clay

C

0

5

10

15

20

25

30

35

0 1 2 3 4 5 6 7

Organic Matter (OM) % by weight

Av

ail

ab

le W

ate

rho

ldin

g C

ap

ac

ity

(A

WC

) (%

by

Vo

lum

e)

Sand

Silt loam

Silty clay loam

Source: Berman Hudson, 1994. JSWC 49:189-194

SOM increases available water holding capacity!

Sand soil Available Water holding Capacity (AWC)

(cm H2O/ 25 cm soil)

(in. H2O/ ft. soil)

SOM = 0% 1% 2% 3%

1.0 cm

0.48 in.

1.5 cm

0.72 in.

2.0 cm

0.96 in.

2.6 cm

1.25 in.

Source: Berman Hudson, 1994. JSWC 49:189-194.

soil

matrix

water

Soil organic matter “sponge” water +

Silt loam soil Available Water holding Capacity (AWC)

(cm H2O/ 25 cm soil)

(in. H2O/ ft. soil)

SOM = 0% 1% 2% 3%

2.3 cm

1.10 in.

3.2 cm

1.54 in.

4.2 cm

2.02 in.

5.1 cm

2.45 in.

Source: Berman Hudson, 1994. JSWC 49:189-194.

soil

matrix

water

Soil organic matter “sponge” water +

Tillage type

Total

runoff

rate

Sediment

conc.

Sediment

loss

Sed.

Rel.

Loss

(mm) (g L-1) (Mg ha-1 ) (--)

Conventional moldboard plowing to a

depth of 18 cm followed

by two diskings

45.0b 36.4c 15.5c 52

Conservation chisel-plow tillage with

straight-shank chisel plow

28.9b 12.5b 3.3b 11

No-tillage direct seeding

7.6a 4.7a 0.3a 1

Source: Seta, A. K., R. L. Blevins,* W. W. Frye, and B. J. Barfield.

1993. Reducing Soil Erosion and Agricultural Chemical Losses with

Conservation Tillage. J. Environ. Qual. 22:661-665 (1993)(table 1)

“Conservation tillage” is poor conservation!

Many water quality problems

are a result of intensive tillage

and rainfall that leads to

erosion and sedimentation.

Some environmental quality problems are easy to see.

Last year’s crop

residue-with tall stalks

left in the soil-help

protect this field. No till

and residue

management help

prevent soil erosion

and polluted runoff

A 3 to 4 inch deep fan

of mud fills the

bottom of this large,

steep and unprotected

field. Multiple gullies

scar the sloping land

at this location.

Conventional tillage (inversion)

- unprotected soils.

“Conservation tillage” (non-inversion)

- poorly protected soils.

No-Tillage (direct seeding)

- fully protected soils.

Poor “Conservation” Has Consequences!

Even good residue

management is no longer

enough to protect soil

and water, supporting

practices such as grass

waterways and buffers

are needed to stand up to

heavy rains.

Photo credits: Environmental Working Group, 2013

- a term

used to define

“any” tillage

system with

primary objective

of “reducing soil

and water loss.”

broad

Conservation tillage has very “loose limits” on the

definition of soil disturbance and residue management.

“Conservation tillage”

The term “conservation tillage” fuels a misguided

sense of entitlement and conservation.

What is Conservation Tillage?

The phrase “conservation tillage” is an oxymoron. An

oxymoron is a figure of speech in which incongruous or

contradictory terms appear side by side.

Any form of intensive tillage is not a form of conservation

for the way intensive tillage degrades and fractures the

natural soil structure. Tillage destroys or disturbs the

ecosystems of soil fauna so important for nutrient cycling.

Tillage moves the soil down slope via tillage erosion.

Intensive tillage loosens the soil and buries the crop

residue, allowing the soil to dry, setting up the system for

severe erosion with the next high-intensity rainfall event.

Most “conservation tillage” is more

“tillage” than “conservation”.

Conservation tillage is oversold for its

conservation benefits, the concept is

good, but the actual practice is bad.

No Till Conservation

Management

Terminology Transition away from Tillage

Emphasize conservation

De-emphasize tillage

Emphasize crop residue management

De-emphasize soil disturbance

Carbon Management

We need to change our vocabulary!

Conservation without compromise!

Conservation: “Touch the earth lightly, use the earth gently,

Nourish the life of all the world in our care.” Source: Shirley Erina Murray, 1992

Conservation is a word to be respected,

revered and used to describe agriculture.

However, conservation does not belong in the

same sentence with tillage.

The action of conserving something, in

particular. Preservation, protection, or

restoration of the natural environment, natural

ecosystems, vegetation, and wildlife.

Vo

lum

e s

oil

dis

turb

ed

0

+

Mo

ldb

oa

rd p

low

Dis

c p

low

Ch

ise

l p

low

Ro

tary

til

lag

e

Fie

ld c

ult

iva

tor

De

ep

Rip

pe

r

Su

bs

oil

-HD

Su

bs

oil

-LD

HD = High Disturbance

LD = Low Disturbance

Stu

bb

le m

ulc

h

Ve

rtic

al ti

lla

ge

Slo

t ti

lla

ge

Str

ip t

illa

ge

Red

uced

til

lag

e

Mu

lch

til

lag

e

No

til

l- H

D

No

til

l- L

D

Rid

ge

til

l

Tillage Soil/Residue Disturbance Continuum

Conservation

Tillage Conventional

Tillage

No-

Tillage

Tillage/Planting System

Decreasing intensity and frequency of soil disturbance

Increasing crop residues covering soil

Idea Source: Freidrich Tebrügge Institute of Agricultural Engineering, Justus-Liebig

Univesitat, Giessen; France Dec. 16/17th 2002.

Conventional

Tillage

Conservation

Tillage

Direct

Seeding

Zero Conservation

Much tillage

Some Conservation

Some tillage

Much Conservation

Zero tillage

Tillage Soil Disturbance Continuum

Conservation

Tillage

Conventional

Tillage

Least

disturbance

Most

disturbance

No-

Tillage

Nature’s

way No till Conservation

tillage

Conventional

tillage

Inversion tillage

to 30 cm

Non-inversion

tillage to 46

cm

Minimum

disturbance

to 5 cm

Biological

tillage

Conventional tillage = inversion tillage

Conservation tillage = non-inversion tillage

Direct seeding is farming in Nature’s image!

After Hartwig Callsen

True “C”onservation

is carbon management The two primary practices that contribute to the largest

amount of conservation are:

1.No-Tillage minimizes soil carbon loss.

2.Synergy crops maximizes soil carbon input.

“Connect the dots around Conservation Agriculture”

CA

Time savings Reduced labor

requirements Reduced

machinery wear

Energy

savings

Higher

soil H2O

Reduced air

pollution

Decreased

compaction

Increased

SOM

Improved

infiltration Improved

water quality

Reduced soil

erosion

More

wildlife

Improved

soil

biology

Continuous

crop residue

cover

Diverse rotations/

cover crops

Minimum soil

disturbance

Dead crop residue = “passive protective blanket”

“conserves water”

“releases nutrients”

“Carbon” coverings for the soil!

Live crop biomass = “active protective blanket”

“extracts water”

“accumulates nutrients”

Both are food

sources for the

soil biology!

http://www.rw.ttu.edu/2302_butler/chapter6.htm

Multi-tasking with cover crops!

More than just erosion control!

1. Fit cover crops into the rotation

2. Cover the soil 100% of the time

3. Carbon input 100% of the time

Photo credit: Jill Clapperton

Diversity enables a more sustainable system.

You can’t have soil biology without plants as their host.

“C”over “C”rop “C”ocktails

Synergy Crops

Bringing together the individual crop

benefits into a community of crops whose

synergistic effects to subsequent crops

are greater than the sum of the individual

crop contributions.

Biodiversity

Natural Fertility

Crop biomass ~ 46 %C

Soil organic matter = 58 %C

Difference = 12 %C

Microbial and

fungal

decomposition

Biological

activity =

Nutrient

release

K P Ca Mg

Bo

Cu

S Cl Zn

Mn

Mo Fe Na

C, H, O, N

CO2 CO2

vs

Which is better for the long term? “Pushing”

carbon!

“Pulling”

iron?

Min. soil disturbance

Min. soil loss

Cont. crop residue cover

Diverse rotations

Min. carbon loss

Soil protection

Feed the soil biology

Manage water

Recycle nutrients

Max. carbon input

C Cover

Crops No-

Tillage

Soil Carbon Sequestration

Environmental benefits are spokes

that emanate from the Carbon hub.

- increased water holding capacity and use efficiency

- increased cation exchange capacity

- reduced soil erosion

- improved water quality

- improved infiltration, less

runoff

- decreased soil

compaction

- improved soil tilth and

structure

- reduced air pollution

- reduced fertilizer inputs

- increased soil buffer capacity

- increased biological activity

- increased nutrient cycling and storage

- increased diversity of

microflora

- increased adsorption of

pesticides

- gives soil aesthetic appeal

- increased capacity to handle

manure and other wastes

- more wildlife

Agriculture’s Wheel of Fortune!

C

Carbon

C

Decrease runoff

Decrease erosion

(water, wind, tillage)

increase infiltration

Decrease evaporation

Increase soil water and air

quality

Reduce biological

disturbance

Enables bio-pore

formation

Decrease inputs

Cope with climate

extremes

Decrease crusting

Improved soil tilth

Improves soil structure

Increase profitability

Improve water quality

Improve quality of life of

farmers

Promote biodiversity

Intensify production

Reduce the C footprint and

emission of GHG

Reduce the energy costs

Increase soil organic

matter

increase H2O holding

capacity

increase water use

efficiency

Recycle nutrients

Increased biological

activity

Increased biodiversity

Decrease pollution

Store more water

Reverse soil degradation

Regenerate soil

Increases soil biological

activity

N source, N scavenger,

Conservation Agriculture

Stop Erosion. Save Carbon. Park the Plow!

Credit: Ken Scott, Clear Lake, IA

Time to pack away those plows!

Consider

biological

implications!

Plant

protection

Soil

protection

Carb

on

man

ag

em

en

t

Carb

on

man

ag

em

en

t

Food

Security

Keep your carbon

footprint small and

manage carbon for

ecosystem services! CO2 CO2

CO2 CO2

Best done with no-till & cover crop mixes!

Environmental Quality Triangle

Soil

Q

Carbon is the Foundation of Soil Quality. Soil Quality

is the foundation of Environmental Quality.

The Monitoring Tool Box is a

Land Stewardship project

publication. Land Stewardship

Project is a private, nonprofit

organization committed to fostering

an ethic‘ of stewardship for

farmland, promoting sustainable

agriculture, and developing

sustainable communities.

You must measure

before you can manage!

Monitoring Topics Quality of Life, Farm Sustainability

with Financial Data, Birds,

Frogs and Toads, Soil, Streams,

pests and pesticide usage, pasture

vegetation

C

C Decrease runoff

Decrease erosion

(water, wind, tillage)

increase infiltration

Decrease evaporation

Increase soil water and air

quality

Reduce biological

disturbance

Enables bio-pore

formation

Decrease inputs

Cope with climate

extremes

Decrease crusting

Improved soil tilth

Improves soil structure

Increase profitability

Improve water quality

Improve quality of life of

farmers

Promote biodiversity

Intensify production

Reduce the C footprint and

emission of GHG

Reduce the energy costs

Increase soil organic

matter

increase H2O holding

capacity

increase water use

efficiency

Recycle nutrients

Increased biological

activity

Increased biodiversity

Decrease pollution

Store more water

Reverse soil degradation

Regenerate soil

Increases soil biological

activity

N source, N scavenger,

C

H2O

N

P

Cycle

of

Life

C

H2O

N

P

Cycle

of

Life

C

H2O

N

P

Cycle

of

Life

Click for pictures of life and activity behind the lifecycle

chart in the four nutrient cycles.

Reduced soil disturbance and

increased retention of crop residues

on the soil surface improve soil

porosity, water infiltration and

holding capacity, and can reduce

erosion from water and wind by

90% or more. This results in less

sedimentation ditches, streams,

rivers and lakes. Reduced

sedimentation improves fish habitat

and minimizes the need for

dredging. Less soil erosion also

reduces offsite movement of

agricultural chemicals tied to the

soil particles.

http://www.directseed.org/overview.htm

Pacific Northwest Direct Seed Association

Conservation Agriculture and

Water Quality

Food security is soil security is national security

“C”onservation Agriculture

Soil “C”onservation

Soil “C”arbon

C

Soil erosion must be minimized!

Global water quality depends on global soil quality

Soil carbon is linked to all measures of soil quality.

“Ecosystems and the services they provide are financially significant and …. to degrade and damage them is tantamount to economic suicide.” Klaus Toepher, head of the U.N. Environment Program.

Water is our greatest natural

resource. We can not let it

“slip further down the slope

of silt, sewage, and sludge.”

Source: Minnesota Gov. Tim Pawlenty 6/24/03

“This is an urgent matter of human development, and

human dignity. Together, we can provide safe, clean

water to all the world’s people. The world’s water

resources are our lifeline for survival, and for

sustainable development in the 21st century.

Together, we must manage them better.”

Kofi A. Annan

Water is essential for life.

Message of the United Nations Secretary-General

to launch the “Water for Life" decade.

22 March 2005

Conservation agriculture and carbon

management can play a big role in

resource management.

Source: Ann Fischer, NRCS, Baker, MT

Tillage creates a battle field for the

soil biology that is trying to help us.

Conservation is all about carbon.

Excel in carbon management.

Food Security Conservation

is not a

burden on

the budget

Conservation

is an

investment in

food security

Excel in carbon management.

Synergy crops provide many

little-understood benefits in the

complex soil-plant system.

** Soil Biology Team ** The “living soil”

Earthworms, insects and rodents are the most visible components

of the “living soil” team. They work in tandem either soil

microorganisms and fungi to contribute to aeration and nutrient

cycling as part of a “soil factory” team effort.

Most “soil critters” are bothered by tillage!

No “flow” No “blow” No “glow”

Conservation Agriculture

Carbon Management No-Till, Zero Till, Direct Seed