Alleviating Compaction

Transcription

1 Alleviating Compaction

2 Pea Harvest: Tractor and trailer GPS Log This is for only 1 tractor and trailer of a pair: Field area is 14.8 ha Tractor wheel marks total 20km (1 tractor)

3 Specific resistance and energy requirements Ploughing on trafficked and non-trafficked fields System kn/sq.m kj/ha Trafficked Non-trafficked After: Chamen, Silsoe Research Institute

4 Traffic control effects on field operations and energy (MJ/ha) needs No traffic Trafficked Harrow 25 Spring tine 57 Drill 27 Power Harrow 108 Roll 27 Harrow 29 Drill 31 Roll 30 TOTAL A 3.23 x INCREASE in ENERGY After: Chamen,SRI

5 Compaction:- Tyre load and inflation pressure N.B. Ignoring carcass effects Pressure = Weight/Area Area = Weight/Pressure Weight = Pressure x Area W Carcass stiffness effects (approximate) Tractor tyre psi P Combine tyre Low ground pressure tyre psi psi A

6 Effects of load, inflation pressure and speed LOW SPEED HIGH SPEED Weight Low Weigh Low Weight High Weight High Pressure High Pressure Low Pressure Low Pressure Low Pressure distribution Pressure has the greatest influence on the degree of compaction and load influences the depth of soil compaction

7 Surface effects

8 Sub surface effects 0.6m

9 After: Soane, Godwin & Subsurface effects - pans Sub-soiling benefits are limited to:- * sandy soils with * spring sown crops in * years of moderate to severe drought

10 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

11 Harvesting Heavy machines and getting heavier?

12 Gross weight, tonnes After: Erickson et al 1974 Gross weight of a range of vehicles Drills Sprayer Spreader Tractor Combine Trailer Tanker Truck Beet Harvester Pea Harvester

13 Inflation presure, psi Tyre inflation pressure of a range of vehicles Drills Sprayer Spreader Tractor Combine Trailer Tanker Truck Beet Harvester After: Erickson et al 1974

14 After: Soane, 1981 Options for reducing compaction Options Controlled traffic Traffic reduction Uncontrolled traffic Permanent tracks Temporary track Low mass Medium mass High mass Wide wheels Restricted? Gantries Tramlines Load reduction Lower inflation pressure Extended track widths Linked operations New wheel/track systems

15 Tread lightly - the alternatives 4 pairs of equal size dual tyres.v. Rubber tracks 66 in 30 in Typical Weight = 18tons / 40,000lbfs Power = 375 hp Total contact area = 3,920 in in 2 Average Contact Pressure = 10.2 psi (MINIMUM) 6.2 psi After: Goodyear & Caterpillar, 2001

16 Tyre selection Fit the largest section/diameter tyre at the lowest safe working pressure Trailers can be the main culprit

17 Terra (low ground pressure) tyres

18 Duals

19 Dual tyres on combine & tractor + chaser wagon

20 Narrow section Go for diameter- large contact patch

21 Beet Harvester ~ Tyre Configuration 55 tonnes

22 Inflation pressures 55 tonnes bar Central tyre inflation systems are available for conversion from field to road to field inflation pressures

23 Compaction issues 20 + tonnes 7 bar 25 tonnes 2 bar (1 bar better)

24 Laboratory studies 3 tyre sections (500/ , 700/ , 800/ ) 3 inflation pressures(13, 23, 33 psi) 3 soil bearing capacities 1 weight (4.5 tonnes)

25 Reduced Tyre Pressures and Central Tyre Inflation systems N.B. Lower pressure tyres would need Central Tyre Inflation System to enable safe road use Rut Depth 200mm Inflation Pressure Road/High speed 33 psi Field/Low speed 13 psi 140 mm Initial density 1.25 g/cc

26 Depth, cm Effect of inflation pressure on soil strength Penetration resistance, MPa Stranks, Dresser and Godwin, 2004

27 Rubber Tracks

28 Effect of track weight distribution Pressure, psi 18.5t Challenger on 2 x 2.1m 2 rubber tracks average contact pressure 6.5psi? Balanced Original 48% Time, seconds Rydberg,2003

29 Compaction alleviation - Rubber tracks 28 tonnes 32 tonnes Extra cost 1/ha over the working life of the combine

30 Track and Tyre Evaluation 0-14t 0-12t

31 Deformation measurement +/- 2mm

32 Depth (mm) Depth (mm) Soil deformation Tyre Track Width (mm) Width (mm)

33 Depth (mm) Compaction reduction - Rubber tracks 11 t 30 t Deformation (mm) Displacement (mm) t 900 followed by followed by 500 Track followed by 700 Track followed by 500 Dominator LSD

34 Pressure Pressure Track pressure distribution mm Ceramic pressure transducer Track position

35 pressure (bar) 10 9 Pressure from a Truck tyre: 5 t, 7bar 250 mm depth Max Pressure = 9.27 bar time (s)

36 Pressure (bar) 7 Effect of wheel/track system on pressure at 250mm road harvester rear harvester rear track harvester dual harvester track 5t, 7bar 10t, 2bar tractor 10t, 1bar tractor 12t 5t, 2bar 2t, 1bar 5t, 1bar 5t 2t, 2bar 2t, 1bar

37 Depth (mm) Effect of ground drive and depth on soil pressure Pressure (bar) 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

38 Controlled Traffic Systems: <10% surface wheeled After: Tullberg et al (2003) Simple concept Standardise wheel centres Industry resistance to change in broad acre crops Narrower track solutions under investigation

39 Tillage and traffic effects on runoff Results from Queensland 1354 mm rain in 2 years Wheeled Controlled Traffic mm % mm % Conventional Tillage % % Zero Tillage % % After: Tullberg, 1996

40 Yield from Low Ground Pressure Trial Cranfield University and TAG Plot 7 Zero Traffic Plot 8 Normal traffic Plot 9 Zero traffic +tracked combine t/ha 0.84t/ha 12.14t/ha After: Phillpot, Stobart, Mouasen and Godwin, 2008

41 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

42 Tramline management Cross drain with mole plough OR Runoff Chisel or side inclined tines on upper tramline wheelmark only

43 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

44 From: Cross Compliance Guidance for Soil Management Defra 2005

45 Practical Aspects Soil disturbance from subsoilers & track and tyre systems.

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53 Depth (mm) Whole Machine Comparison Deformation (mm) /10.5/ /10.5/ /4.5/ /10.5/ /4.5/2.3 T12 T12-700/4.5/1.0 T /4.5/2.3 LSD Track system Tyre system

54 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

55 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: hp 9 tonnes Ploughing tractor psi Seedbed work, duals 10 psi Track: Cat 55 for most seedbed work 6-7 psi Trailers: Tandem axle 11 tonne psi 14 tonne psi 17 tonne Potato boxes 60 psi Combine: 25 tonne 30 35psi Sugar beet harvester: 6-row, full tank tonne psi Sprayer: 3600 l capacity tank, terra tyres 9 psi, narrow tyres psi

56 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: hp 9 tonnes Ploughing tractor 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 psi 14 tonne 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 tonne psi contractor machine with larger tyres Sprayer: 3600 l capacity tank, terra tyres 9 psi, narrow tyres psi improve tramline management Operating procedures Large fields, harvesters unloading into trailers within fields. chaser bins

57 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 > info@daledrills.com tel >

58 Practical application for field vegetables RTK-GPS enables < +/ mm positional error. Issues of repeatability and cost are being addressed After: Chamen (2007) Controlled traffic system for vegetable production using RTK-GPS and 300 mm wide rubber tracks.track positions are at 3.15 m centres After: Vermuelen (2006)

59 Dual-Trac for narrower track width tractors Assisted by Autosteer John Deere tractors with independent link suspension for the front axle Also use for harvesters 8 m seed drill 8 m harvester 24 m chemical application After: Shaw and Chamen (2005) 3 m 2 m After: Shaw and Chamen 2005

60 Moore Unidrill