Crop Residue Management

Contributions from Dr Jack Desbiolles (Ashworth et al., 2010) and Baker et al., (2007)

Jack McHugh

Stubble Management

Crop residue cutting

Residue managers

Overview

Tine systems: short residue, well spread to maximise trash flow

Discs Systems: Long residue, well spread.

Minimise blade interaction – cut high & spread chaff evenly

Orientation of crop residue is significant factor in disc seeder performance and crop establishment

Overview

Stubble management for disc seedersRetain stubble, uniformity of spread

Therefore maximise stubble height

Reduced soil erosionIncrease water infiltration (matting?)Increased OM and C sequestrationReduced evap - Increased WUEHeat insulationWeed smotheringNutrient release

Increase handling problems. (Hair pinning, poor clearance)Reduced herbicide efficacy

Reduced hair pinningIncrease water capture Reduced evap from windEven soil moisture and crop estabSeedling protectionIntegrated before sowing (herbicide) IBS improvedFurther increases in WUE

Reduced radiation and soil tempInter row evap and run off

Benefits Limitations

Inter row sowing

Minimise disc opener residue interactionAccess to all agronomic benefitsBest IBS operation

Investment in precision guidanceImplement trackingUnsuitable for narrow row (<22mm)Increased seeding ratesPossible nutrient deficiency

Benefits Limitations

Knife rollers

Maximum benefitsbut – must operate seeder in same direction of rolling…..if not:• Reduced penetration• Reduced row clearance• Reduced emergence

Characteristics & Operations

Spreading and choppingCritical

Reducing chaff and stubble density by harvesting high & spreading evenly

Pinning reduced Reduced humidityBetter furrow closureReduced soil moisture variabilityOptimise weed control (pre-emergents)

Chopping: Higher inputReduces widthNutrient tie upReduced establishmentReduced herbicide effectivenessPest and disease pressure (rotation)Increased runoff (matting)

Spreading improves with cutting height – straw full width & chaff at least 50%• rotor speed and deflector setting critical

Crop Residue CuttingCutting – application of sliding and wedging forces

High disc speed improves sliding (Bubble, ripple, turbo + sweep angle to increase speed ratio)Strong soil backing maximises wedging

Other factors:

Disc size (Larger is best but Increased draft)

Disc sweep angle (drive, self sharpen, disturbance)

Depth (Deeper is best but pinning can occur)

Notch & tooth features (Deeper, drive, shear & sliding

action, lower vertical forces)

Sharpness and fineness (improved wedging action –

maintenance critical)

Avoid the residue (inter row, directional rolling)

CA Transplanter video

Crop Residue Managers

Crop Residue ManagersDesigned to improve stubble handling by :

Removing (row cleaners)Improve residue cutting (pinning)

Clear the path (ground driven, notched curved straight fingers, toothed, coulter style)

Adjustable (to dir of travel – flexibility for heavy or wet residue and soft soils)

Floatation for least soil disturbance

Fixed (only float attached to seeding unit, must be close to opener)

Floating (fully independent)

Aggressive – large amounts of residue – soil for driveWide – more residue clearanceOff set – soft conditions

Flotation and drive – suited to soft soils – can be used for herbicide incorporation

Down pressure (adjustable springs to cope with load)

Contour following (swing arm/parallelogram - independent of opener)

Flotation (treader wheels or depth rings)

Adjustable aggressiveness (minimum opening – limited by rows)

Maintain high speed (8-10km – monitor performance. Erosion, moisture loss, crusting)

General specifications