1. Crop Residue Management Stubble ManagementCrop residue cuttingResidue managers Jack McHugh Contributions from Dr Jack Desbiolles (Ashworth et al., 2010) and Baker et al., (2007)

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

3. Overview 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

4. Stubble management for disc seeders Retain stubble, uniformity of spread Benefits Limitations Increase handling problems. (Hair pinning, poor clearance) Reduced herbicide efficacy Reduced soil erosion Increase water infiltration (matting?) Increased OM and C sequestration Reduced evap - Increased WUE Heat insulation Weed smothering Nutrient release Thereforemaximise stubble height Reduced hair pinning Increase water capture Reduced evap from wind Even soil moisture and crop estab Seedling protection Integrated before sowing (herbicide) IBS improved Further increases in WUE Reduced radiation and soil temp Inter row evap and run off

5. Inter row sowing Benefits Limitations Minimise disc opener residue interaction Access to all agronomic benefits Best IBS operation Investment in precision guidance Implement tracking Unsuitable for narrow row (<22mm) Increased seeding rates Possible nutrient deficiency

7. Reduced row clearance

10. Crop Residue Cutting Cutting – 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

11. Crop Residue Managers

12. Crop Residue Managers Designed 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)

13. Aggressive – large amounts of residue – soil for drive Wide – more residue clearance Off set – soft conditions

14. Flotation and drive – suited to soft soils – can be used for herbicide incorporation General specifications 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)