Effect of narrow opener geometry on

lateral surface soil movement and

implications for no-till seeding

Barbara Hardy Institute – Agricultural Machinery Research and Design, University of South Australia

2011

A. A. Solhjou, J. Fielke and J. Desbiolles

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ISSTIntroduction

Tined no-till opener

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ISSTExcessive soil disturbance

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ISST

Excessive soil disturbance by tined no-till openers leads to increased:•Depth of soil cover on alternate furrows•Pre- emergent herbicide contamination above the seed zone•Weed seed germination•Soil moisture loss

Problems of excessive soil disturbance

Poor seed germination

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ISSTMaterial and Methods

•A flat narrow point opener•Experimental design: randomized complete block design with n= 4 rep.•Treatments:Rake angles: 35°, 53°, 72° and 90°•Forward speed (v) : 8.2 km/h•Work depth (d): 120 mm

•Commercial bent leg opener•V= 8.2 km/h and d= 120 mm- n=2

Bent leg opener

Flat opener

1

2

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ISSTRake angle

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ISSTTracers location before tillage

15

Ver

tica

l int

erva

l (m

m)

0

90

75

450

0

30 -30

50

100

10 20 -20 -10

0

-2 -1 3

2

-3

30

60

1

Lateral interval (mm)

105

120

-6 -4 -5 5

4

6

120 90 60 -120 -90 -60

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ISSTX-Y-Z digitising frame

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ISSTLaser soil profile meter

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ISSTMeasuring bottom soil profile with laser

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ISSTTracer locations after tillage

90°

35°

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations- n=4

α= 35°

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations- n=4

α= 53°

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations- n=4

α= 72°

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations- n=4

α= 90°

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations - n= 2 (commercial bent leg opener)

Bent leg

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ISSTResults

1. Opener geometry strongly affects on patterns of surface soil movement.

2. Flat opener rake angles clear pre-emergent

herbicide above seed zone. However, these rake angles move pre-emergent herbicide onto the adjacent furrow.

3. Bent leg opener reduces soil movement on the

adjacent furrow (uniform seed germination).

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ISSTResults

4. Bent leg opener reduces lateral surface soil movement (pre- emergent herbicide) into adjacent furrow compare to flat openers (crop safety).

Thank you

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ISST

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ISSTCommercial bent leg opener

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ISSTEffect of rake angle on average lateral tracer movement

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ISSTTracer locations after tillage

Cross section of soil profile and tracer locations - n= 2 (commercial bent leg opener)

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ISSTEffect of rake angle on soil failure in the front of openers

35° 90°

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ISSTTracer locations after tillage for

opener rake angle of 90° and commercial bent leg opener

α= 90°

Bent leg

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ISSTEffect of rake angle on average lateral tracer movement