Soil Water Repellence Long-term management solutions

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Soil Water RepellenceLong-term management
solutions

• Stephen Davies, Paul Blackwell (DAFWA Geraldton)
• Craig Scanlan, Breanne Best (DAFWA Northam)

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Managing Water Repellence
Mitigation Options Amelioration Options
Improved furrow sowing Clay spreading or delving
Banded wetting agents Soil inversion (Mouldboard plough)
Blanket-applied wetting agents Rotary spading
Full retention/minimal disturbance
On-row seeding
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Wheat yield responses 2007-11
Mouldboard Mouldboard Rotary Spader Rotary Spader
Yield response (kg/ha) Range, kg/ha (number) Yield response (kg/ha) Range, kg/ha (number)
Year 1 583 0-1965 (17) 609 -656-2000 (17)
Years 2/3 259 0-633 (9) 204 41-500 (4)
Years 4/5 764 378 1150 (2) ? ?
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Yield response summary

• 15 of 17 trials had good yield responses in year
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• Good mouldboard plough response 4 5 years
• Risks seeding depth problems, sandblasting,
  haying off and recompaction of loosened soil
• Average lupin yield response in MB 405kg/ha over
  7 trials
• Lupin response at Badgi in 2011 spaded in 2009
  was 500 kg/ha

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GSR 324 mm MARCHAGEE
Spaded 2011 Biomass 7.7 t/ha 326 heads/m2 Grain
yield 3.3 t/ha
Knife Points Biomass 3.5 t/ha 193 heads/m2 Grain
yield 1.5 t/ha
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West Moora Deep yellow Sandplain 334 mm GSR
Control
Spaded 900 kg/ha grain 2840 kg/ha biomass
Acknowledgement Erin Cahill AgVivo Moora
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Badgingarra Pale Deep Sand 485 mm GSR
Untreated Control
Mouldboard in 2010 1000 kg/ha lupin in 2011
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Visual changes in soil colour and root density
Untreated
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Visual changes in soil colour and root density
Rotary Spader
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Visual changes in soil colour and root density
Mouldboard Plough
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Root distribution
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Pale deep sand, Badgingarra
Buried topsoil
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Established late 1980s, organic carbon measured
in 2003
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Mouldboard
Nil Mouldboard
Wheat yield increases 250 kg/ha in 2010 950 kg/ha
in 2011
gt 800 brome/m2
0 brome/m2
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Modified Skimmers
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Average leaf area diseased (average of top 4
leaves) for Calingiri wheat sown on 8 June
Soil Treatment Soil Treatment Soil Treatment
Crop Growth Stage Days after sowing Nil Rotary Spader Mouldboard Plough l.s.d. (5)
Z37 (Stem elongation) 72 17 15 9 4
Z55 (Ear emergence) 118 49 39 35 10
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Negative Responses
Control Mouldboard Plough Rotary Spader
Grain Yield (t/ha) 2.9 2.9 2.4
Protein () 10.6 11.0 13.4
Screenings () 4.6 8.8 15.2
Extractable Aluminium (mg/kg) 8.0 _at_ 20-30 cm gt12
_at_ 40-50 cm
Acknowledgement Bernie Quade, Landmark, Geraldton
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Wind happens
Neridup 2011
Badgingarra 2011
Mouldboard
Control
Photos Colin DeGrussa
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Summary

• Generally good yield responses
• Best on soils with reasonable potential deep
  sandy earths, loose sandy gravel , deep sandy
  duplex
• Haying off risk check subsoil for constraints,
  variety selection, seeding rate?, N rate
• Maximise opportunities incorporate lime,
  micronutrients and other amendments weed
  control break crops

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1965 kg/ha
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Clay Spreading 2 systems
High rates gt250 t/ha
Moderate rates lt150 t subsoil/ha
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All shallow incorporation 100-150mm
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Badgingarra Clay Rate Demo Incorporation with
offset discs 100-150mm
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Clay-spreading on water repellent sands

• Lower application rates (lt150 t/ha) with shallow
  (100-150mm) incorporation
• Spread with a multi-spreader
• Incorporated with offsets or even
  cultivator/combine tines.
• Lower cost and less reliance on contractors.
• Risk of poor yield responses in drier seasons are
  reduced.
• Deep incorporation of lower application rates is
  not beneficial.
• 2. Higher application rates (gt250 t/ha) with deep
  (200-250 mm) incorporation
• Spread using carry graders then smudged
• Incorporated with spader or another deep working
  implement.
• Higher cost and reliance on contractors.
• Potentially higher yield gains, particularly in
  wetter seasons or environments.
• Shallow incorporation of higher clay rates is
  risky

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Funded by GRDC and DAFWA (DAW00204) Agronomic
strategies for water repellent soils