disc seeders in conservation agriculture - an australian survey
DESCRIPTION
Jack Desboilles University of South AustraliaTRANSCRIPT
UNIVERSITY OF SOUTH AUSTRALIA
Disc Seeders in Conservation Agriculture
- An Australian survey
Dr Jack Desbiolles
Engineering for Sustainable Agriculture
Barbara Hardy Institute
Institute for Sustainable Systems and Technologies
ISST
• Background on Australian no-till and disc seeder technology
• Benefits and limitations (2007 disc seeder user survey)
• Example on-farm strategies for challenging soil/residue situations
Institute for Sustainable Systems and Technologies
ISST% farmers using no-till/zero-till in 2008
(after Llewellyn and D’Emden, 2010)
77-94% (88%)
n=6
55-85% (76%)
n=5
68-81% (75%)
n=3
45-89% (78%)
n=4
72% n=1
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ISST Australian no-till seeding
1. Narrow opener & press wheel system
2. Water harvesting press-wheel furrows
3. Soil applied pre-emergence herbicides ‘incorporated by sowing’ (IBS)
Herbicide-free seed
row
Herbicideconcentration on inter-row
Institute for Sustainable Systems and Technologies
ISST
• Disc seeder ownership in Australia (2008)(after Llewellyn and D’Emden, 2010) 19 regions surveyed across 5 states (1170 farmers)- 11% farmers in 17 Southern regions - 52% farmers in 2 Northern regions (summer cropping)- half of these farmers own both tine & disc seeders
• Over last 3 years, the industry is witnessing a significant increase in disc seeder interest and purchase (over 50 brands available in Australia)
Recent trends in no-till seeders
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ISST “Small” scale disc seeders
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ISST Large scale disc seeders
Seeding systemrow unit
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ISSTE.g. Single disc seeding systems
Tilt
Sweep
TRAVEL
vert
ical
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ISSTE.g. Double disc seeding systems ± coulters
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ISST2007 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
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ISSTSurvey methodology
• Questionnaire peer reviewed and pilot tested• Sample-population contacts obtained via no-till
associations, farming system groups, disc seeder suppliers etc…
• Targeted mail-out + on-line survey form advertised across professional media (Feb-Sept 2007) and no-till associations
• Incentives: open strategy of knowledge sharing across users and potential adopters, prize draw (NT books)
• Follow-up phone calls to strengthen data sets
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ISST Response overview
195 survey responses
from winter & summer cropping systems
from cropping areas of 100-18,000 ha
29% from long term no-till adopters (>12 years)
10% from recent no-till adopters (1-3 years)
26% from <250mm Growing Season Rainfall
22% from >350mm GSR
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ISST Benefits in the cropping system
• Ability to retain and handle heavy stubble (58%)
No soil degradation (soil erosion control) Improved water infiltration & preservation in profile
enhanced water use efficiency and grain yield potential Improved soil health and biological activity No stubble management, harvesting & seeding made
easier (fuel/labour savings), improved efficiency at harvest
Cropping system flexibility (opportunity crop rotations)
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ISST
• Low soil disturbance + seed placement accuracy (35%)
More even, rapid and reliable crop establishment Seedbed moisture conservation = longer sowing window Lower weed seed germination Smoother paddocks Better ability to establish
or regenerate pastures Reduced seed inputs Reduced clods under
dry-sowing
Benefits in the cropping system
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ISST Benefits in the cropping system
• High work rates (23%) faster sowing = improved timeliness & yield potential labour & fuel savings per ha = better efficiencies
• Handling stony soils (10%)
Improved cropping results in stony paddocks no stone harvesting or paddock rolling needed smoother stony paddocks after seeding
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ISST Disc seeder limitations(% responses)
*Technology specific
limitations
• Poor handling of sticky soils (68%)• Inadequate herbicide incorporation* (38%)• Lack of ground penetration ability (35%)• Residue pinning (34%)• Early bearings failure * (34%)• Damage and high wear in stony soils*• Irregular seed placement*• Poor furrow closure in wet compact clays*• Pre-emergence herbicide crop damage*• Poor disc drive in soft soils*• High draft in compacted soils*• Furrow smearing & compaction in wet clay*
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ISST E.g. management strategies“residue hairpinning”
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ISST
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ISST i) Residue avoidance techniques
Minimise residue load on the ground- maximise stubble height - uniformly spread all loose residue
Inter-row sowing to avoid the bulk of standing residue
Use row clearing residue managers to remove the excess loose/matted residue
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ISST ii) Maximising residue cutting capacity
Operate in dry residue, cutting along residue stem direction
Cutting process = wedging + sliding cut actions
Effective wedging requires a sharp cutting edge + strong soil backing
Ensure sufficient down force onto disc matches requirements
Sliding cut component is improved with a high speed ratio
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ISST E.g. Disc blade speed ratio (VT/V0)
Benefits of tangential flutes
Agricultural Machinery Research and DesignCentre
Directa blade Ingersoll - Argentina
Travel directionsStandard
modeReverse mode
VT
V0
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ISST E.g. management strategies for “sticky soils”
Excessive soil build-up can significantly impair seeding system functions
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ISST 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
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ISST 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)
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ISST
Take Home Messages
Disc seeders are being successfully adopted in Australia by an increasing number of no-till farmers
Disc seeder adoption is motivated by many short and long term benefits, affecting cropping efficiency, sustainability and productivity
Technological solutions and optimised field practices help manage limitations found in challenging soil/residue conditions
Disc seeders are seen as a tool to enable best practice in zero-till cropping, and which benefit most under controlled traffic systems
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ISSTSupport also acknowledged from
And a majority of disc seeder suppliers and farming system groups
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ISST 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