Jack Desboilles University of South Australia

1. UNIVERSITY OF SOUTH AUSTRALIA Disc Seeders in Conservation Agriculture - An Australian survey Dr Jack Desbiolles Engineering for Sustainable Agriculture Barbara Hardy Institute

3. Benefits and limitations (2007 disc seeder user survey)

5. Herbicideconcentration on inter-row Herbicide-free seed row Australian no-till seeding Narrow opener & press wheel system Water harvesting press-wheel furrows Soil applied pre-emergence herbicides ‘incorporated by sowing’ (IBS)

8. Large scale disc seeders Seeding system row unit

9. vertical Tilt Sweep TRAVEL E.g. Single disc seeding systems

10. E.g. Double disc seeding systems ± coulters

11. 2007 survey of disc seeder users Aim to document: i) disc seeder benefits and limitations experienced on-farm across a range of soil and rainfall conditions and disc seeder technologies ii) the strategies adopted to deal with disc seeder limitations

13. Sample-population contacts obtained via no-till associations, farming system groups, disc seeder suppliers etc…

14. Targeted mail-out + on-line survey form advertised across professional media (Feb-Sept 2007) and no-till associations

15. Incentives: open strategy of knowledge sharing across users and potential adopters, prize draw (NT books)

18. No soil degradation (soil erosion control)

19. Improved water infiltration & preservation in profile  enhanced water use efficiency and grain yield potential

20. Improved soil health and biological activity

21. No stubble management, harvesting & seeding made easier (fuel/labour savings), improved efficiency at harvest

23. More even, rapid and reliable crop establishment

24. Seedbed moisture conservation = longer sowing window

25. Lower weed seed germination

26. Smoother paddocks

27. Better ability to establish or regenerate pastures

28. Reduced seed inputs

30. Handling stony soils (10%)  Improved cropping results in stony paddocks no stone harvesting or paddock rolling needed  smoother stony paddocks after seeding

32. Inadequate herbicide incorporation* (38%)

33. Lack of ground penetration ability (35%)

34. Residue pinning (34%)

35. Early bearings failure * (34%)

36. Damage and high wear in stony soils*

37. Irregular seed placement*

38. Poor furrow closure in wet compact clays*

39. Pre-emergence herbicide crop damage*

40. Poor disc drive in soft soils*

41. High draft in compacted soils*

42. Furrow smearing & compaction in wet clay**Technology specific limitations

43. E.g. management strategies “residue hairpinning”

48. E.g. management strategies for “sticky soils”  Excessive soil build-up can significantly impair seeding system functions

49. i) Field operation - Timing: delay seeding until ‘dry surface crust’ is formed - Shallow depth - Faster speed - minimise gauge wheel loading - start & stop out of the ground

50. ii) Technology upgrade - Maximise disc driving ability with:  Higher speed (momentum)  Reduced friction resistance - remove poor design scrapers - increase clearances between rotating components - upgrade with effective & well located scrapers - Reduce mud collection (open wheel rim designs) - Promote mud shedding (flexing gauge tyres)

52. Disc seeder adoption is motivated by many short and long term benefits, affecting cropping efficiency, sustainability and productivity

53. Technological solutions and optimised field practices help manage limitations found in challenging soil/residue conditions

55. Further information: State No-Till Associations WANTFA: www.wantfa.com.au SANTFA: www.santfa.com.au VNTFA: www.vicnotill.com.au CANFA: www.canfa.com.au CFI: www.cfi.org.au GRDC Groundcover-Direct Catalogue 2011:  www.grdc.com.au/uploads/documents/GRDC-GroundcoverDirectCatalogue201105-101.pdf