Alleviating Compaction

This is for only 1 tractor and trailer of a pair:

Field area is 14.8 ha

Tractor wheel marks total 20km (1 tractor)

Pea Harvest:Tractor and trailer GPS Log

Ploughing on trafficked and non-trafficked fields

System kN/sq.m kJ/ha

Trafficked 107 117

Non-trafficked 42 47

After: Chamen, Silsoe Research Institute

Specific resistance and energy requirements

No traffic Trafficked

Harrow 25 Spring tine 57

Drill 27 Power Harrow 108

Roll 27 Harrow 29

Drill 31

Roll 30

TOTAL 79 255

After: Chamen,SRI

A 3.23 x INCREASE in ENERGY

Traffic control effects on field operations and

energy (MJ/ha) needs

Compaction:- Tyre load and inflation pressure

• Pressure = Weight/Area

• Area = Weight/Pressure

• Weight = Pressure x Area

W

P

A

N.B. Ignoring carcass effects

Carcass stiffness effects (approximate)

Tractor tyre + 1.5 psi

Combine tyre + 7.0 psi

Low ground pressure tyre + 0.7 psi

Effects of load, inflation pressure and speed

Weight Low Weigh Low Weight High Weight High

Pressure High Pressure Low Pressure Low Pressure Low

1

112

2

2

2

33

3

34

Pressure distribution1

Pressure has the greatest influence on the degree of

compaction and load influences the depth of soil compaction

LOW SPEED HIGH SPEED

Surface effects

Sub surface effects

0.6m

Subsurface effects - pans

Sub-soiling

benefits are

limited to:-

* sandy soils

with

* spring sown

crops

in

* years of

moderate to

severe drought

After: Soane, Godwin &

Spoor, 1985

2 Problem areas

1. Re-compaction of loosened soil during

crop establishment

2. Further re-compaction of settled soil at

harvest time

Which resolve into :

1. Size

2. Weight

3. Pressure

Harvesting

Heavy machines and getting heavier?

Gross weight of a range of vehicles

0

10

20

30

40

50

60

70

Drills

Spra

yer

Spre

ader

Tract

or

Com

bine

Traile

r

Tanke

r

Truck

Bee

t Har

vest

er

Pea

Har

vest

er

Gro

ss w

eig

ht,

to

nn

es

After: Erickson et al 1974

0

20

40

60

80

100

120

Drills

Spra

yer

Spre

ader

Tract

or

Com

bine

Traile

r

Tanke

r

Truck

Bee

t Har

vest

er

Infl

ati

on

pre

su

re,

psi

Tyre inflation pressure of a range of vehicles

After: Erickson et al 1974

Options for reducing compaction

Options

Controlled traffic Traffic reduction Uncontrolled traffic

Permanent tracks Temporary track

Linked operations

Low mass Medium mass High mass

Gantries

Extended track widths

Wide wheels

Load reduction

Lower inflation pressure

New wheel/track systems

Restricted?

Tramlines

After: Soane, 1981

Tread lightly - the alternatives

Typical Weight = 18tons / 40,000lbfs Power = 375 hp

Total contact area = 3,920 in2 6426in2

Average Contact Pressure = 10.2 psi (MINIMUM) 6.2 psi

30 in66 in

4 pairs of equal size dual tyres .v. Rubber tracks

After: Goodyear & Caterpillar, 2001

Tyre selection

Fit the largest section/diameter tyre at the

lowest safe working pressure

Trailers can be the main

culprit

Terra (low ground pressure) tyres

Duals

Dual tyres on combine & tractor + chaser wagon

Narrow section

Go for diameter- large contact patch

Beet Harvester ~ Tyre Configuration

55 tonnes

55 tonnes

Central tyre inflation systems are

available for conversion from field

to road to field inflation pressures

800-70x38

@ 1.6-1.9 bar

Inflation pressures

Compaction issues

25 tonnes

20 + tonnes

7 bar

2 bar (1 bar better)

Laboratory studies

3 tyre sections (500/65-22.5, 700/50-26.5, 800/40-26.5)

3 inflation pressures(13, 23, 33 psi)

3 soil bearing capacities

1 weight (4.5 tonnes)

200mm

Rut

Depth

Reduced Tyre Pressures and Central TyreInflation systems

Inflation Pressure

Field/Low speed

13 psi

140 mm

N.B. Lower pressure tyres would

need Central Tyre Inflation System

to enable safe road use

Road/High speed

33 psi

Initial density 1.25 g/cc

Effect of inflation pressure on soil strength

Stranks, Dresser and Godwin, 2004

Penetration resistance, MPa

Depth

, cm

Rubber Tracks

Effect of track weight distribution

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Time, seconds

15

45

30

Pressure, psi

48%

Balanced

Original

Rydberg,2003

18.5t Challenger on 2 x 2.1m2 rubber

tracks average contact pressure 6.5psi?

Compaction alleviation - Rubber tracks

28 tonnes

32 tonnes

Extra cost £1/ha over the

working life of the

combine

Track and Tyre Evaluation

0 - 14t 0 - 12t

23/03/2009 Land Rover Short Course –

Godwin32

+/- 2mm

Deformation measurement

23/03/2009 Land Rover Short Course –

Godwin33

Soil deformation

0 200 400 600 800 1000 1200 1400

1000

900

800

700

600

500

400

300

200

Width (mm)

Depth

(m

m)

Tyre Track

0 200 400 600 800 1000 1200 1400

1000

900

800

700

600

500

400

300

200

Width (mm)

Depth

(m

m)

0

100

200

300

400

500

600

700

-20 0 20 40 60 80 100 120

Deformation (mm)

De

pth

(m

m) 900 followed by 700

900 followed by 500

Track followed by 700

Track followed by 500

Dominator

LSD

30 t

33 t

Displacement (mm)

11 t

Compaction reduction

- Rubber tracks

23/03/2009 Land Rover Short Course –

Godwin35

Track pressure distribution

-0.5

0

0.5

1

1.5

2

8.5 9 9.5 10 10.5 11 11.5 12 12.5

Time (s)

Pre

ss

ure

Track position

Pre

ssure

Sensor @ 250mm

Ceramic pressure

transducer

Pressure from a Truck tyre: 5 t, 7bar

-1

0

1

2

3

4

5

6

7

8

9

10

14 15 16 17 18 19 20

time (s)

pre

ssure

(bar)

Max Pressure = 9.27 barSensor @ 250 mm depth

0

1

2

3

4

5

6

7

road harvester rear

tractor

harvester rear

tractor

track harvester dual harvester track human

Pre

ss

ure

(b

ar)

5t, 7bar 10t, 2bar 10t, 1bar 12t 5t, 2bar 2t, 1bar 5t, 1bar 5t walking

2t, 2bar 2t, 1bar

Effect of wheel/track system on pressure at

250mm

-700

-600

-500

-400

-300

-200

-100

0

0 1 2 3 4 5 6 7

Track 5t

Road 5t-7bar

Tractor 2t-1bar

Tractor 2t-2bar

Dual 2t-1bar

Harvester 10t-2bar

Harvester 10t-1bar

Harvester 5t-1bar

Harvester 5t-2bar

Track_12t

Pressure (bar)

De

pth

(m

m)

Effect of ground drive and depth on soil pressure

• Simple concept

• Standardise wheel centres

• Industry resistance to

change in broad acre crops

• Narrower track solutions

under investigation

Controlled Traffic Systems:

<10% surface wheeled

After: Tullberg et al (2003)

Tillage and traffic effects on runoff

Wheeled Controlled Traffic

mm % mm %

Conventional Tillage 322 100% 266 83%

Zero Tillage 282 88% 166 52%

Results from Queensland

1354 mm rain in 2 years

After: Tullberg, 1996

Plot 7 Zero Traffic Plot 8 Normal traffic Plot 9 Zero traffic +tracked combine

Yield from Low Ground Pressure Trial Cranfield University and TAG

After: Phillpot, Stobart, Mouasen and Godwin, 2008

12. 52 t/ha 0.84t/ha 12.14t/ha

Effective subsoiling

Limited evidence of crop response to deep loosening in

UK soils unless for spring sown crops in sandy soils in

years with low rainfall

Tramline management

Runoff

Chisel or

side inclined

tines on

upper

tramline

wheelmark

only

Cross drain with mole plough

OR

Conclusions

• Do all you can to reduce load and pressure

• Spread load where possible

• Keep compaction as shallow as possible – easier

and cheaper to remove

• Minimise random traffic

• Work in sensible patterns

• If damage occurs repair it as soon as is

practicable

• Follow the soil loosening advice given earlier

From:

Cross Compliance

Guidance for Soil

Management

Defra 2005

Practical Aspects

Soil disturbance from

subsoilers

& track and tyre systems.

Whole Machine

Comparison

0

100

200

300

400

500

600

700

-15 5 25 45 65 85 105

Deformation (mm)

Depth

(m

m)

900/10.5/1.9

900/10.5/1.9-

700/4.5/1.0

900/10.5/1.9-

500-70/4.5/2.3

T12

T12-700/4.5/1.0

T12-500-

70/4.5/2.3

LSD

Track system Tyre system

Case study

Considering the farm given in the Appendix

a. What soil problems may arise on the different soils requiring tillage to

alleviate and during the actual tillage operations? Indicate the likely

nature, extent and depth of the problems where appropriate, relating

them to different working conditions.

b. What tillage systems would be appropriate for establishing cereals

after harvest? Indicate likely working depths, equipment needs and

potential workrates.

c. Considering tyres/tracks and field operating procedures, indicate the

opportunities which would be available to reduce soil problem and

hence future tillage needs

i. with existing equipment

ii. when replacing equipment

APPENDIX

Soil types:Chalky and sandy soils

Area: 950 ha (400 ha cereals)

Soils: chalky soils on slopes, a shallow clay cap

Loamy sand/sandy loam soils on flat areas, some with inherent high water table

Crops/succession: sugar beet, potatoes, vegetables, cereals

Root crops irrigated

Cereals follow both root crops and cereals

Root crops usually follow cereals

Equipment weights and pressures:

Tractors:

Wheel: 150 – 190 hp 9 tonnes

Ploughing tractor 18 – 20 psi

Seedbed work, duals 10 psi

Track: Cat 55 for most seedbed work 6-7 psi

Trailers:

Tandem axle

11 tonne 45 – 50 psi

14 tonne 45 – 50 psi

17 tonne Potato boxes 60 psi

Combine:

25 tonne 30 – 35psi

Sugar beet harvester:

6-row, full tank 35-40 tonne 40 – 45 psi

Sprayer:

3600 l capacity tank, terra tyres 9 psi, narrow tyres 35-40 psi

Operating procedures

APPENDIX

Soil types: Chalky and sandy soils

Area: 950 ha (400 ha cereals)

Soils: chalky soils on slopes, a shallow clay cap good soil water holding capacity / tramline erosion/ runoff

Loamy sand/sandy loam soils on flat areas, some with inherent high water table capping/slumping

Crops/succession: sugar beet, potatoes, vegetables, cereals beds/controlled traffic consider drainage

Root crops irrigated capping

Cereals follow both root crops and cereals could be damaged after beet harvest/deep loosen-as and when

Root crops usually follow cereals

Equipment weights and pressures:

Tractors:

Wheel: 150 – 190 hp 9 tonnes

Ploughing tractor 18 – 20 psi consider move to tracked tractor/reduced tillage for cereals

Seedbed work, duals 10 psi

Track: Cat 55 for most seedbed work 6-7 psi could reinvest in larger version next time around to increase work rates

Trailers:

Tandem axle

11 tonne 45 – 50 psi

14 tonne 45 – 50 psi - larger tyres/lower pressure/chaser bins

17 tonne Potato boxes 60 psi

Combine:

25 tonne 30 – 35psi -rubber tracks??

Sugar beet harvester:

6-row, full tank 35-40 tonne 40 – 45 psi contractor machine with larger tyres

Sprayer:

3600 l capacity tank, terra tyres 9 psi, narrow tyres 35-40 psi improve tramline management

Operating procedures

Large fields, harvesters unloading into trailers within fields. – chaser bins

John Dale

Seed Hawk Tines

•1+2 Seed Location

•3 Packed Surface

•4 Tungsten Carbide Cutters

•5 Pneumatic Packer / Depth Wheel (good mud release)

•6 Seed Coulter (½" (12.5mm) wide)

•7 Seed Drop Tube

•8 Seed Coulter

•9 Trip plate

•10 Chain

•11 Depth Lock Bolt

•12 Depth Gauge (accurate to 1/8") (3mm)

•13 Hanging Bracket

•14 Hydraulic Cylinder

•15 Placement Arm

•16 Seed Drop Tube

email > info@daledrills.com tel > 01652 653326

Practical application for field vegetables

After: Vermuelen (2006)

Controlled traffic system for vegetable production using RTK-GPS and

300 mm wide rubber tracks.Track positions are at 3.15 m centres

RTK-GPS enables < +/- 20 - 30 mm positional error.

Issues of repeatability and cost are being addressedAfter: Chamen (2007)

Dual-Trac for narrower track width tractors

After: Shaw and Chamen 20053 m 2 m

24 m chemical application

8 m harvester

8 m seed drill

•Assisted by “Autosteer”

•John Deere tractors with “independent

link suspension for the front axle”

•Also use for harvesters

After: Shaw and Chamen (2005)

Moore Unidrill