bmps for the wheat/soybean double-crop system part 2 ... · pdf filebmps for the wheat/soybean...

BMPs for the Wheat/SoybeanDouble-crop System

Part 2: Relay Soybean

Tony J. VynPurdue University

Tony Vyn, Purdue University 2003

Wider Wheat Row Widths

15” wheat 7.5” wheat

Wheat seeding options:1. Drill or row-crop planter2. From 10” to 20” rows3. Skip-row in tractor/sprayer tire tracks


Other Wheat Management Variables:

• Fertility similar to traditional double crop except more emphasis on avoiding lodging with excessive N fertilizer

• Herbicide restrictions for broadleaf weed control

• Variety selection


Wheat Variety Choice for Relay Cropping?Considerations:

1. Architecture2. Maturity3. Yield4. Height


0102030405060708090

100

2000Relay

2001Variety

7.5" row

15" row

15" rowplus relay

Wheat Yields in Wide RowsY

ield

s (b

u/a

c)

2001 Relay


Wheat seeding rate in 15” rows

010203040

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600,000 800,000 1,200,000

Yie

lds

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A)

Seeds per acre


Relay Soybean Management

• Variety Selection (disease resistance, stress tolerance, maturity, internodelengths?)

• Seeding rate (intermediate between full season and double-crop)

• Seed treatment beneficial• Consistent seeding depth• Weed control


Polymer Coated Soybeans for Relay Cropping?


Relay Soybean EmergenceFigure 1. 1999 Northern Indiana Soybean Emergence.

0

50

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200

0 5 10 15 20 25 30 35 40 45 50 55 60

Days After Planting

Popu

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A B C Uncoated

Figure 2. 2000 Northern Indiana Soybean Emergence

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5 10 15 20 25 30 35 40 45 50 55 60

Days After Planting

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Soybean Heights with Relay Cropping


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Full SeasonSoybeansCoated

Uncoated

Soybean Heights at Wheat Harvest

Romney 2000 (May 11)

Wanatah2000 (May 8)

Hei

ght

(in

.)


Wheat Harvest Management with Relay Soybeans

Issues:

1. Timing (earlier preferred)

2. Header height

3. Header width and wheel tracks

4. Straw Management

5. Volunteer wheat control


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WideCombine

PlotCombine

Full SeasonSoybeansBestCoatingUncoated

DoubleCrop

2000 Soybean Yields in Central Indiana

Yie

ld (

bu/a

c)


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WideCombine

PlotCombine

Full SeasonSoybeansBestCoatingUncoated

DoubleCrop

2001 Soybean Yields in Central Indiana

Soyb

ean

Yie

ld (

bu/a

c)


Soybean Yields at SEPAC(Butlerville, IN)

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2000 2001

Full SeasonSoybeansRelaySoybeansDoublecrop


Relay or Full Season or Double-crop ?

1. Location (relative to I-70)2. Equipment/Timing Issues3. Soil Moisture Availability4. Maturity5. Relative Yield

Conclusions:1. Relay soybean superior to double-crop north of Interstate 70

2. Wide row wheat is surprisingly successful

3. Minimize damage to wheat when relay planting, and to soybeanwhen harvesting wheat

4. Variety selection critical (in both wheat and soybean).

5. More profitable than wheat alone or soybean alone?


Polymer Coatings for Relay Soybeans ?

• Emergence delays with coated seed results in shorter and sturdier soybean plants at wheat harvest.

• Biggest advantage may be for early planting into winter wheat.

• Cost relative to benefit?


Acknowledgements:

• Landec Ag (Monticello and Oxford, IN)• Purdue Research Foundation• Graduate student (S. McCoy), technical

assistants and farm superintendents


References

• Kline, A.M., S.M. McCoy, T.J. Vyn, T.D. West and E. P. Christmas. 2003. Management Practices for Relay Intercropping: I. Wheat. AY-315, Purdue University Cooperative Extension Service

• McCoy, S.M., T.J. Vyn, A.M. Kline, T.D. West and E. P. Christmas. 2003. Management Practices for Relay Intercropping: II. Soybean. AY-316, Purdue University Cooperative Extension Service

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