Tillage and Compaction Impact

On Soil Aggregate Associated Properties

Kenan Barik, Ataturk University, Turkey

and

Randall Reeder, Alan Sundermeier, Yogi Raut,

Rafiq Islam, Stacey Reno, and Jim Hoorman

Ohio State University, Ohio

Kenan Alan Jim Rafiq

Heavy farm machinery compacts the soil, both on

tilled ground and no-tilled ground.

Plowing and subsoiling degrade soil structure by

dispersing macro-aggregates.

Tillage breaks up roots, fungal hyphae and other

important living organisms.

No-Till minimizes soil erosion, benefits soil biology,

and increases soil aggregate stability.

Data on soil physical properties is useful to evaluate

a soil.

Conclusions Compaction from a big grain cart

(18 Mg/axle) affected soil aggregate

properties on both continuous no-till and

annually subsoiled plots.

No-Till, to some extent,

can improve the

aggregate properties of soil.

Compaction research since 1988

Materials and Methods

Field experiment was established on Hoytville clay

loam in 3 x 2 factorial arrangement of RCB design in

Wood County, northwest Ohio.

Materials and Methods

The factors were:

1) Compaction: control, 9 and 18 Mg/axle loads

2) Tillage: no-till and annual tillage (subsoiling)

Compaction with a 600-bu grain cart

(full = 18 Mg/axle; half full = 9 Mg/axle)

Results and Discussion

Compaction caused a significant decrease

in:

•Concentration of aggregates 1-2 mm

•Concentration of >2 mm, and

•Stability of macro- and micro-aggregate,

MWD, GMD, and ratio of macro- and micro-

aggregates.

Compaction increased concentration of

smaller aggregates <0.053 mm.

Soil compaction (Mg)

0 5 10 15 20

Ag

gre

gate

siz

e d

istr

ibu

tio

n (

%)

0

5

10

15

20

0.125 - 0.25 mm: y= 6.5 + 0.34*X

0.053 - 0.125 mm; y = 5.5 + 0.028*X

<0.053 mm: y = 16.6 - 0.1*X + 0.01*X2

*

*

*

More compaction means more small aggregates…

Soil compaction (Mg)

0 5 10 15 20

Ag

gre

ga

te s

ize

dis

trib

uti

on

(%

)

0

5

10

15

20

25

30

>2 mm: y = 7.6 - 0.14*X

1 - 2 mm: y = 20.1 +0.06*X -0.016*X2

0.5 - 1 mm: y 24.2 - 0.13*X

0.25 - 0.5 mm: y = 18.3 + 0.044*X *

*

…and fewer large aggregates

Compaction increased the cone

penetration resistance and bulk density.

The impact was mainly with the heavier

axle load (18 Mg).

Cone penetrometer resistance

(depth, 0-30 cm)

Soil compaction (Mg)

0 5 10 15 20

Pene

tratio

n r

esis

tance

(kP

a)

0

500

1000

1500

2000

2500

CT: y = 1190.2 - 15.8*X +2.5*X2

NT: y= 1629 - 21.1*X + 2.6*X2

Cone penetrometer resistance

(depth, 0-30 cm)

Soil compaction (Mg)

0 5 10 15 20

Penetr

ation r

esis

tance

(kP

a)

0

500

1000

1500

2000

2500

CT: y = 1190.2 - 15.8*X +2.5*X2

NT: y= 1629 - 21.1*X + 2.6*X2

Soil compaction (Mg)

0 5 10 15 20

Pene

tratio

n r

esis

tance

(kP

a)

0

500

1000

1500

2000

2500

0 - 15 cm: y = 1254.6 - 24.7*X + 2.9*X2

15 - 30 cm: y = 1564.6 - 12.3*X + 2.1*X2

Compacting load had more effect near surface

No-Till increased cone penetration resistance

and soil bulk density compared with

subsoiling.

Tillage

CT NT

Pe

ne

tra

tio

n r

esis

tan

ce

kP

a)

0

500

1000

1500

2000

2500

0 - 15 cm

15 - 30 cm

Effects LSDp<0.05

Tillage **

Soil depth **

* 95% **99% ***99.9%

Cone Penetrometer resistance

Tillage

CT NT

So

il b

ulk

de

nsity (

g c

m-3

)

1.0

1.2

1.4

1.6

1.80-15 cm

15-30 cm Effects LSDp<0.05

Tillage **

Soil depth **

Soil Bulk Density

Soil compaction (Mg)

0 5 10 15 20

Soil

bulk

density (

g c

m-3

)

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

0-15 cm: y = 1.41 + 0.18(1-exp(-0.11*X))

15-30 cm: y = 1.55 + 0.0045*X

9 Mg axle load had more effect on soil density near surface;

Adding 9 Mg did not double the change in density.

Deeper soil started at higher density; linear relationship for axle load

No-Till significantly increased:

• Proportion of >2 mm size aggregates

• Macro- and micro-aggregate stability

• Mean Weight Diameter (MWD)

• Geometric Mean Diameter (GMD)

Change in soil aggregate associated

properties decreased significantly with depth.

Tillage

CT NT

Ag

gre

ga

te s

ize

dis

trib

uti

on

(%

)

0

5

10

15

20

25>2 mm

1-2 mm

0.5-1 mm

0.25-0.5 mm

0.125-0.25 mm

0.053-0.125 mm

0.053 mm

*

* *

*

#

#

With No-Till, more large aggregates, fewer small ones

Tillage

CT NT

Ag

gre

ga

te s

tab

ilit

y (

%)

20

30

40

50

60

70

80

MacAS

MicAS

AS*

*

*

No-Till increased Stability of Macro-Aggregates

Tillage

CT NT

Ag

gre

gate

siz

e (

um

)

300

350

400

450

500

550

600

650

MWD

GMD

*

*

No-till increased MWD and GMD

As mean weight diameter (MWD) of aggregates

increased:

Macro-aggregate stability increased and

Micro-aggregate stability decreased.

Mean weight diameter (um)

400 450 500 550 600 650 700

Ag

gre

ga

te s

tab

ility

(%

)

0

20

40

60

80

100

Macrogrregate stability: y = -42.7 - 0.37*X - 0.0003*X2

Microaggregate stability: y = 42.3 - 0.37*X + 0.0003*X2

No significant interactive effects of soil depth

with compaction or tillage on aggregate

properties.

No significant impact of compaction x tillage

interaction on soil aggregate size.

Conclusions

Compaction consistently affected soil

aggregate properties, for both no-till and

subsoiling systems.

No-Till, to some extent, can improve the

aggregate properties of soil.

Tillage and Compaction Impact On

Soil Aggregate Associated Properties

Kenan Barik, Ataturk University, Turkey

Randall Reeder, Alan Sundermeier, Jim Hoorman,

Yogi Raut, Rafiq Islam and Stacey Reno

Ohio State University