AgEng 2007 Soil Protection and Cultivation€¦ · AgEng 2007 Soil Protection and Cultivation...

AgEng 2007 Soil Protection and Cultivation

Systematic approaches of soil mechanical stress induction: impact assessment and implications for energy efficiency enhancement in agricultural engineering

M. Sc. agr. Stephan Denker, University of Applied Sciences SüdwestfalenProf. Dr. Ludwig Volk, University of Applied Sciences SüdwestfalenProf. Dr. Wolfgang Lücke, Georg-August-University of Göttingen

Thursday, 08 November 2007

Presentation’s outline

• Introduction - Different aspects of field traffic- Project aims and project partners

• Ag Eng approaches on stress induction and impact assessment- Simulating field traffic- Impact assessment by vertical and horizontal penetrometry- Experimental design

• First year’s results• Conclusion and outlook


Field traffic: impact on soils

• Increase of:- Soil bulk density- Penetration resistance

• Decrease of:- Aeration- Water conductivity- Total pore volume- Root penetrability

• Alteration of:- Functionality of pore system


Field traffic: impact parameters

Effect of field traffic is depended upon different parameters:• Soil parameters (water content, soil type, organic substance, load bearing capacity)• Chassis parameters (wheel load, type of tire, tire inflation pressure)• Wheeling intensity (number of passes, speed of travel, wheel slip)


Field traffic: energy aspects

Wheeling is a process of elastic and plastic deformation of soil and rubber:• Tire is being deformed elastically• Soil underneath and before the tire is being deformed elastically and/or plastically• Rut depth is the visible result of plastic soil deformation• Rolling, deformation and flexing processes require energy

Direction of travel

Flexing zone

Rutdepth

Bulldozing

Soil compaction


Project: aims

Project’s aims:• Simulation of field traffic and investigation of its impact on soil• Quantification of the stability of arable soils against mechanical stresses by different methods• Evaluation of the feasability of these methods of detecting soil compaction on a field scale• Deduction of implications for practical agriculture and decision makers


Project: partners

Project partners:Christian-Albrechts-University Kiel (CAU)• Institute of Plant Nutrition and Soil Physics• Institute of GeophysicsGeorg-August-University Göttingen• Institute of Agricultural Engineering

Geophysics: ground penetrating radar (GPR) and EM38

Soil physics: displacement and stress state transducer systems (DTS, SST)


Sensor-fitted load frame (SFL)

Simulating field traffic: • Tire mounted: 650/75 R 32• Wheel loads of 3.3, 6.3 and 7.5 Mg• High and low tire inflation pressure applied at each wheel load, ranging from 50 to 350 kPa• Velocity of 1.4 m s-1

• Total of five wheeling incidents over the project’s duration


Vertical penetration resistance

Penetration resistance:Soil’s resistance against

penetration by sensor [MPa]

Penetration resistance [Mpa]

Soi

l dep

th [c

m]


Soest Horizontal Penetrometer (SHP)

• Data from 3 sensors is obtained simultaneously • Working depth up to 50cm• Prismatic sensor heads for the detection of compacted soil layers• Measurement instrumentation completely outside of soil and protected• For data resolution reasons operating speed chosen to be 0.3 m s-1


Experimental design: sites

• Experimental sites:- Kiel (luvisol derived from sandy loam)- Soest (luvisol derived from loess)

• Tillage systems used:- Conservation tillage (cs.)- Conventional tillage (cv.)

• Project duration 2 ½ years• Wheeling in spring and fall under moist soil conditions with 6 variants• Set-up of experimental plots in block-design with 3 repetitions

Kiel

Soest


Experimental design: variants

Wheel load (WL)Tire inflation pressure A

Tire inflation pressure B

WL1: 3.3 Mg 50 kPa 160 kPa

WL2: 6.3 Mg 160 kPa 250 kPa

WL3: 7.5 Mg 250 kPa 350 kPa

w h e e l i n g

m a r k i n g l i f t i n g

m e a s u r i n g


Experimental design: field plot

• 2 wheeling incidents annually perpendicularly to main tillage direction• VP measurement before and after each wheeling incident• SHP measurements once annually in main tillage direction• Simultaneous measurements from soil physics and geophysics department of CAU

SHP lanes2006

SHP lanes2008

SHP lanes2007

Spring 2006Fall 2006Spring 2007Fall 2007Spring 2008



Analysis of vertical penetration resistance prior to first wheeling:• Vertical penetrometer (VP) reveals differences between the tillage systems used (cs, cv) for both experimental sites• Differences between the experimental sites themselves (Kiel, Soest) due to different soil texture, stone and water content

Ap

Ap

ApAp



2006, overall average


Soest Horizontal Penetrometer Data

SHP shows different grades of penetration resistancedepending on:- Working depth- Tillage system- Experimental site

Kiel, cv.

Kiel, cs.

Soest, cv.

Soest, cs.

2006, overall average


VP versus SHP: comparison of data

SHP data shows:- Lower penetration resistances

measured in the horizontal direction

- Generally a good compliance with VP-Data

Soest, cv.Soest, cs.Kiel, cs.

0,0 1,0 2,0 3,00

10

20

30

40

50

Penetration resistance [Mpa]

Soil

dept

h [c

m]


Rolling resistance measurement

A1 B1 A2 B2 A3 B3

0,0

2,0

4,0

6,0

8,0

10,0

12,0

Rol

ling

resi

stan

ce [k

N]

Tillage systemcs. tillagecv. tillage

Tillagesystem

Tire inflationpressure

50 kPa3.3 Mg

160 kPa3.3 Mg

160 kPa6.3 Mg

250 kPa6.3 Mg

250 kPa7.5 Mg

350 kPa7.5 Mg

Soest, fall of 2006


Rut depth as a result of wheeling

Ks A1 B1 A2 B2 A3 B3

-12,0

-10,0

-8,0

-6,0

-4,0

-2,0

0,0

Rut

dep

th [c

m]


• Both factors tire inflation pressure and wheel load are affecting the depth of the ruts• The higher the wheel loads the stronger the effect of the tillage system used

∆ Tire inflationpressure∆ Wheel

load

50 kPa3.3 Mg

160 kPa3.3 Mg

160 kPa6.3 Mg

250 kPa6.3 Mg

250 kPa7.5 Mg

350 kPa7.5 Mg

Soest, fall of 2006


Ruth depth versus rolling resistance

Ks A1 B1 A2 B2 A3 B3

0,0

2,0

4,0

6,0

8,0

10,0

12,0

Rut

dep

th [c

m]

Tillage systemcv. tillagecs. tillage

A1 B1 A2 B2 A3 B3

0,0

2,0

4,0

6,0

8,0

10,0

12,0

Rol

ling

resi

stan

ce [k

N]


50 kPa3.3 Mg

160 kPa3.3 Mg

160 kPa6.3 Mg

250 kPa6.3 Mg

250 kPa7.5 Mg

350 kPa7.5 Mg

50 kPa3.3 Mg

160 kPa3.3 Mg

160 kPa6.3 Mg

250 kPa6.3 Mg

250 kPa7.5 Mg

350 kPa7.5 Mg

Soest, Fall of 2006


Conclusions

• Experimental sites are of good conditions in terms of the project’s aims• Promising experimental design has been found for investigating the impact of the factors related to mechanical stress• Good compliance found between vertical and horizontal penetration resistances• Rolling resistance and rut depth found to be influenced by bothwheel load and tire inflation pressure• In terms of energy demand and soil deformation the tillage system becomes more important at higher wheel loads


Outlook

• Further data analysis with increasing number of passes• Increase in data-resolution of VP and SHP down to the single variants• Closer investigation of relation between vertical and horizontal penetration resistance• Consolidation of Ag Eng data with data from the Institutes of Soil Physics and Geophysics


Acknowledgements

Thank you very much for your attention!

This project is being financially supported by the

Federal Ministery of Food, Agriculture and Consumer

Protection (BMELV) via the Federal Agency for

Agriculture and Food (BLE)


Announcement

Please visit part of the project’s equipment in

Hall 16, A 03 Stand of: University of Applied Sciences Südwestfalen

Hall 11, Pavillion CWorld Soil and Tillage Show

AgEng 2007 Soil Protection and Cultivation€¦ · AgEng 2007 Soil Protection and Cultivation...

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