Disc Seeders in Conservation Agriculture - An Australian survey

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


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


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


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


ISST “Small” scale disc seeders


ISST Large scale disc seeders

Seeding systemrow unit


ISSTE.g. Single disc seeding systems

Tilt

Sweep

TRAVEL

vert

ical


ISSTE.g. Double disc seeding systems ± coulters


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


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


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


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)


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


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


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*


ISST E.g. management strategies“residue hairpinning”


ISST


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


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


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


ISST E.g. management strategies for “sticky soils”

Excessive soil build-up can significantly impair seeding system functions


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


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)


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


ISSTSupport also acknowledged from

And a majority of disc seeder suppliers and farming system groups


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

http://www.wantfa.com.au/

http://www.santfa.com.au/

http://www.vicnotill.com.au/

http://www.canfa.com.au/

http://www.cfi.org.au/

Disc Seeders in Conservation Agriculture - An Australian survey

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