TILLAGE EFFECTS ON SOIL

PROPERTIES

Dick Wolkowski

Department of Soil Science

University of Wisconsin

WHAT IS TILLAGE

THE PHYSICAL MANIPULATION OF

THE SOIL FOR THE PURPOSES OF:

Management of previous crop residues

Control of competing vegetation

Incorporation of amendments

Preparation of a seedbed

SOIL PROPERTIES AFFECTED

BY TILLAGE

Crop residue cover

Soil test measurements

Nutrient availability

Structure and aggregate stability

Water relationships

Temperature

Strength

SURFACE CROP RESIDUE

INTERACTS WITH OTHER FACTORS

Impact on erosion

Cooler soils

Conserves moisture

Affects soil physical

properties

Affects carbon and

nutrient cycling

TILLAGE EFFECT

EROSION ON CLEAN-TILLED

GROUND, DANE CO., WIS.

CROP MANAGEMENT EFFECT

EROSION ON CORN SILAGE

GROUND SHAWANO CO., WIS.

TILLAGE INTENSITY IN WISCONSIN

VARIES BY CROP

0

10

20

30

40

50

60

70

Corn Soybean Forage

% o

f Acr

eage

NT

MT

RT

CT

CTIC, 2002

EFFECT ON SOIL TEST

Nutrients “stratify” in long-term no-till

Surface acidification

Soil sampling concerns

Benefit to P and K banding

Banded fertilizer response more likely in

no-till

SOIL TEST STRATIFICATION FOLLOWING

FIVE YEARS OF TILLAGE MANAGEMENT,

ARLINGTON, WIS.

0 10 20 30 40 50 60 70

NT

CH

SOIL TEST P (ppm)

0 25 50 75 100 125 150 175 200

NT

CH

SOIL TEST K (ppm)

6-8" 4-6" 2-4" 0-2"

5 5.5 6 6.5 7

NT

CH

SOIL pH

Wolkowski, 2003 (Corn/soybean rotation)

REDUCED TILLAGE IS MORE

RESPONSIVE TO BANDING

Positional availability

Surface vs. sub-surface

Wheel track vs. non-wheel track effects on

root distribution

Reduced P and K fixation by the soil

Reduced K uptake from zones of poor

aeration

FERTILIZER PLACEMENT AFFECTS

CORN ROOT DISTRIBUTION (0-15 IN.)

Root length (km/m3)

Tillage Fert.

placement

Row Untracked

Inter-row

Tracked

Inter-row

CH ROW 17.1 3.0 0.8

CH INTER-ROW 12.0 4.4 1.4

NT ROW 19.8 2.5 0.8

NT INTER-ROW 10.8 6.1 1.5

Kaspar et al., 1991

CC SbC

CH ST NT CH ST NT

------- % ------- ------- % -------

NONE 2.23 2.37 2.35 1.65 1.34 1.40

BDCT 2.35 2.19 2.51 2.51 2.18 1.40

2 x 2 2.85 3.26 2.31 2.46 2.58 2.16

EFFECT OF ROTATION, TILLAGE, AND FERTILIZER ON

CORN K CONCENTRATION 45 DAP, ARLINGTON, WIS.

Wolkowski, 2003

CORN RESPONSE TO STARTER:

PLANTING DATE AND TILLAGE

0

5

10

15

20

25

YIE

LD

RE

SP

ON

SE

(b

u/a

)

PLOW NO-TILL

EARLY MAY

LATE MAY

BUNDY AND WIDEN, 1991 (3 YR. AVG.)

LOWER N AVAILABILITY IN

REDUCED TILLAGE SYSTEMS

No-till/reduced tillage:

Lower and slower mineralization

Greater immobilization

Volatilization of ammonia from surface urea

and urea-containing materials

Potential for increased denitrification

Higher supplemental N rate for >50% corn

residue recommended (30 lb N/a)

CONTINUOUS NO-TILL CORN

TYPICALLY HAS LOWER N UPTAKE

Oshkosh Janesville

Tillage Earleaf N

%

Grain N

%

Yield

bu/a

Earleaf N

%

Grain N

%

Yield

bu/a

MB 2.92 1.57 159 3.10 1.52 145

CH 2.84 1.55 145 3.05 1.50 137

NT 2.76 1.55 146 2.98 1.47 126

Bundy et al., 1992 (3 yr. avg.)

SOIL C AND N DISTRIBUTION AFTER 12

YEARS OF CONTINUOUS CORN

0

5

10

15

20

25

30

35

40

12.5 50 100 200 275 375 525

Depth (mm)

MB

NT

0

0.5

1

1.5

2

2.5

3

3.5

12.5 50 100 200 275 375 525

Depth (mm)

Tot

al N (mg/c

m3)

MB

NT

Karlen et al., 1994

Total C

0

5

10

15

20

25

12.5 50 100 200 275 375 525

Depth (mm)

NO3-N

(ug/

cm3)

MB

NT

NO3-N

Total N

TILLAGE AND DENITRIFICATION

0

0.5

1

1.5

2

2.5

1 2 3 4 5

Sampling time

N los

s (lb/a

/day)

WT N-WT

Tillage affected loss:

MB = 10 lb/yr

CH = 14 lb/yr

NT = 22 lb/yr

No-till

Lower air-filled porosity

Higher microbial

denitrifier population

More surface organic

carbon

Hilton et al., 1994 (all received 100 lb N/a)

TEN BOTTOM MOLDBOARD PLOW

SET AT 11”, WOOD CO., WIS.

TILLAGE HAS A PROFOUND

EFFECT ON THE SOIL PHYSICAL

CONDITION

EFFECTS OF LONG-TERM TILLAGE ON THE

PLOW LAYER PORE SIZE DISTRIBUTION

0

0.02

0.04

0.06

0.08

0.1

0.12

>150 150-15 15-1.5 1.5-0.3 0.3-0.1

Pore Size

MB

NT

Hill et al., 1985

Pore

vol

ume (

cm3/c

m3)

EFFECTS OF TILLAGE MANAGEMENT ON

MACRO-PORE (>0.4 mm) CONTINUITY

0

200

400

600

800

1000

1200

NT MB

Upper Ap

Lower Ap

Upper B

Lower B

Lancaster, Wis.; continuous corn (Logsdon et al., 1990)

Pore

num

ber

(m2)

AGGREGATE STABILITY

INFLUENCED BY

Organic matter and organisms

Texture

Rotation

Tillage

IMPORTANT FOR:

Aeration

Water relations

Productivity

“HEALTHY” CORN ROOT MASS

TILLAGE EFFECTS ON SOIL (0-2 IN.)

PROPERTIES AT LANCASTER, WIS.

TILLAGE STAB.

AGGR.

TOTAL

C

EARTH

WORMS

RUNOFF

% g/kg No./m2 Mg/ha

No-till 46 24 78 2.1

Chisel 34 16 52 --

Plow 36 11 53 0.5

Karlen et al., 1994

WATER-STABLE AGGREGATE SIZE IN THE

0-3 IN. DEPTH AS AFFECTED BY ROTATION

AND TILLAGE

0

0.5

1

1.5

2

2.5

3

CC CSb SbC SbSb

SIZ

E (

mm

)

FALL MB

FALL CH

NO-TILL

Kladivko et al, 1986

EFFECT OF TILLAGE ON CRUST

STRENGTH AFTER A HEAVY RAINFALL

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

8 12 16

ST

RE

NG

TH

(M

Pa)

MB

NT

UNGER, 1984 DAYS

TILLAGE EFFECTS ON SOIL

WATER RELATIONSHIPS

No-till soils tend to have lower porosity and

higher water content

Considerable variability by soil type

Continuous channels in no-till can increase

infiltration rate

TILLAGE EFFECT ON INFILTRATION

0

50

100

150

200

250

300

INF

ILT

RA

TIO

N (

uM

/s)

NT CH

WT

IR

No-till maintains large

pores

Bare soil crusts

Infiltration varies

during season

Wheel traffic

influences infiltration

Ankeny et al., 1990

RELATIONSHIP BETWEEN SOIL MATRIC

POTENTIAL AND VOLUMETRIC WATER CONTENT

0.25

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0 1 2 3.5 5.9 7.4 20 40

WA

TE

R C

ON

TE

NT

(m

3/m

3)

MB

NT

Hill, 1990 MATRIC POTENTIAL (kPa)

TILLAGE EFFECTS ON SOIL

TEMPERATURE

Cooler temperatures associated with

high residue

Residue buffers temperature change

Emergence and early growth affected

No-till systems have been shown to be

5-10% less productive in Wisconsin

SOIL TEMPERATURE AFFECTED BY

TILLAGE AND CROP RESIDUE

0

5

10

15

20

25

30

11-Apr 18-Apr 24-Apr 2-May 9-May 16-May 23-May

DE

GR

EE

C

STRIP-TILL

CHISEL

NO-TILL

2 " DEPTH

MEASURED 4:00-5:00 PM

Effect on in-row soil temperature,Arlington, 1994

0

20

40

60

80

100

Res

idue

(%)

Chisel

Strip-till

No-till

Effect on cropresidue, Arlington, 1994

Wolkowski, 2000

EFFECT OF TILLAGE ON THE EARLY

GROWTH OF CORN, ARLINGTON, WIS.

TILLAGE EMERGENCE V6 V12 SILKING

plt/ft -------- g/plt -------- %

Strip-till 1.6 1.1 28 62

Chisel 1.8 1.1 29 80

No-till 0.7 0.7 18 36

Wolkowski, 2000

STRIP TILLAGE OFFERS

AN ALTERNATIVE TO

FULL-WIDTH TILLAGE

IN-ROW RESIDUE MGT.

ZONE-TILL PLANTER

STRIP TILLAGE OFFERS AN ALTERNATIVE TO

FULL-WIDTH TILLAGE WITH CONSERVATION

AND AGRONOMIC BENEFITS

TILLAGE EFFECTS ON SOIL

STRENGTH

Reduced tillage soils have higher

surface bulk density

Short-term response to occasional

tillage

Traffic management critical

Subsoiling response is likely site

dependent

EFFECT OF PERIODIC PLOWING ON

SOIL BULK DENSITY (0-3 in.)

1

1.1

1.2

1.3

1.4

1.5

1986 1987 1991

g/c

c

CT

NT/PLOW

NT

Pierce et al., 1994

TILLAGE INFLUENCES

RESISTANCE TO PENETRATION

Lower penetration

resistance in NT at depth

compared to chisel and no-

till

Greater penetration

resistance in wheel track

Larney and Kladivko, 1989

SOIL PHYSICAL PROPERTIES AND CORN

YIELD AS AFFECTED BY TRACKED AND

WHEELED VEHICLES

TYPE BULK

DENSITY

HYDR.

COND.

AIR-FILLED

PORE SPACE

YIELD

g/cc uM/sec % Bu/a

Un-

tracked

1.28 26.0 17.8 166

Steel-

tracked

1.38 13.0 9.7 148

Rubber-

tracked

1.46 7.8 7.7 --

Wheel-

tracked

1.50 2.7 4.7 139

Brown et al., 1992

Given enough horsepower man can

do some really dumb things

Compaction affects the soil

- structure

- porosity

- aeration

- strength

Plant growth affected

- root growth

- nutrient uptake

- water utilization

CORN AND SOYBEAN YIELD AS AFFECTED

BY DEEP TILLAGE, MANITOWOC, WIS.

TILLAGE SOYBEAN

1997

CORN

1998

SOYBEAN

1999

CORN

2000

------------------------ bu/a ------------------------

NT 30 213 57 176

VR 40 188 58 172

ZB 51* 226* 59 192*

Wolkowski (unpublished)

NATURAL ALLEVIATION OF COMPACTION

ON A SILTY CLAY LOAM SOIL

-10

0

10

20

30

40

50

60

1988 1990 1991 1992 1993 1994 1995

YIE

LD

RE

DU

CT

ION

(%

)

10 T

20 T

Al-Adawi and Reeder, 1996

SUMMARY Tillage management can greatly modify

soil properties related to soil quality and

crop growth

Tillage intensity will impact residue

management and soil consolidation

Many physical and chemical properties

are affected

High residue systems need “tweaking” in

Wisconsin

Better traffic and tillage management will

enhance soil quality