Increasing whole-farm wheat yield and reducing risk through early sowing

Increasing whole-farm wheat yield and reducing risk through early sowing

SUSTAINABLE AGRICULTURE FLAGSHIP

James Hunt, Neil Fettell, Jon Midwood, Paul Breust, Brad Rheinheimer, Annieka Paridaen 27 February 2013

Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

Take-home messages

• Know the optimal flowering date in your location and how to achieve it with different varieties from a broad range of sowing dates.

• Slow maturing varieties sown early have a yield advantage over mid-fast varieties (average 0.8 t/ha)

• Including a slow maturing variety in a cropping program (opens sowing window to early April) increases average farm wheat yield by 13-47%

• Yield penalty from sowing later than optimal always greater than sowing earlier than optimal even in frosty springs

• Highest yields in time-of-sowing trials have ~5% frost damage


Recent research on south-east Australian rainfall

• Rainfall reductions over Southern Hemisphere semi-arid regions: the role of subtropical dry zone expansion• Wenju Cai, Tim Cowan Marcus Thatcher - CSIRO Marine and Atmospheric

Research• Published Nature Scientific Reports - October 2012• Last 17 years of dry autumns due to southward shift in sub-tropical ridge

• Southeast Australia autumn rainfall reduction: a climate-change-induced pole-ward shift of ocean-atmosphere circulation• Wenju Cai, Tim Cowan - CSIRO Marine and Atmospheric Research• Published Journal of Climate January 2013• Not connected to southern annular mode• Pole-ward shift in circulation partly attributable to climate change


Temora moves to Macquarie Marshes!!!!

• Subtropical ridge has moved 400 km south in April-May• April-May rainfall trend since 1951


Old Junee Apr-May rainfall

-80-60-40-20

020406080

100120140160180

1891 1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001 2011

Apr-

May

rai

nfal

l ano

mal

y (m

m)

Year


Old Junee Feb-March rainfall

-80-40

04080

120160200240

1891 1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001 2011

Feb-

Mar

ch r

ainf

all a

nom

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(mm

)

Year


What are we going to do about it?

• Conserve as much summer rain as possible – spray summer weeds• See results of GRDC National WUE Initiative 2008-2012

• Dry sow as much area as possible with mid-fast varieties• As much area established as possible when break comes

• Plant winter wheats from late Feb-late April when moisture available

• Plant slow maturing spring wheats from early-late April when moisture available

• Learn how to ‘moisture seek’• Learn Spanish and polo and move to Argentina


Winter & spring wheats

• Winter wheats have a ‘vernalisation’ or cold requirement before floral-initiation (~Z30) begins ~4-11°C.

• Very flexible sowing window – 2 months vs. 2 weeks• Our spring wheats do not have vernalisation, but development is

usually controlled by a ‘photoperiod’ or day-length requirement• Eaglehawk, Bolac > Bounty, Gregory > Gauntlet, Suntop > Lincoln, Axe

Emergence – Z30 Z30-Z69 Z69-maturityJan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Emergence – Z30 Z30-Z69 Z69-maturity

Winter wheat

Mid maturing spring wheat

Emergence – Z30 Z30-Z69 Z69-maturitySlow maturing spring wheat


Sowing and flowering dates

Optimal flowering window

Wedgetail sowing window (winter wheat)Eaglehawk sowing

window (slow maturing spring wheat)

Janz sowing window (early-mid maturing spring wheat


Why slow maturing wheats sown early?• Allow earlier sowing to take advantage of stored soil water without frost risk associated

with mid-fast varieties• Widen sowing window in face of decreasing sowing opportunities and larger farm sizes

• Subtropical ridge has moved 400 km south in April- May (Temora = Nyngan)

• Reduce yield losses from water-logging• Dual purpose option• Long season wheats sown early should in theory;

• Use more water (deeper roots, longer growing season)• Transpire a greater proportion of water• Transpire more efficiently (more growing during lower VPD)• Grow more dry-matter & have higher yield potential

• But they don’t yield more than short-season wheats sown late• Riffkin et al. 2003 rain-fed wheat at Hamilton• Stapper & Fischer 1990 irrigated what at Griffith


Pre-experimental modelling

• Three environments (high, medium & low rainfall)• Lake Bolac• Temora• Condobolin

• Use modelling to identify optimal flowering window• APSIM frost & heat multiplier (after Farre et al. 2010)• Minimum T 0 < 2°C Z60-69 = 10% yield loss• Minimum T -2 < 0°C Z60-75 = 20% yield loss• Minimum T < -2°C Z60-79 = 90% yield loss

• Use ToS experiments and modelling calculate how to get cultivars of different maturity to flower in correct window


Lake BolacLake Bolac - 1890-2008

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Flowering date

Yie

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YieldFrost & heat yield


Temora

Temora - 1890-2009

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Condobolin

Condobolin - 1889-2009

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Sowing times consistent across environments

Maturity group Variety (site) Optimal sowing date

Very slow Forrest (LB)Eaglehawk (T, C)

15 April

Slow Bolac (LB, T, C) 25 April

Mid Derrimut (LB, T) Gregory (T, C)

5 May

Fast Lincoln (LB, T, C) 15 May

Very fast Axe (C) 20 May


Improving WUE of early sown wheat• Management to improve harvest index

• Very low plant density• Plant growth regulators

Maturity class Sowing date15 April 27 April 9 May 19 May

Very slow (Eaglehawk)

40 pl/m² +PGR40 pl/m² -PGR100 pl/m² +PGR100 pl/m² -PGR

100 pl/m² -PGR 100 pl/m² -PGR 100 pl/m² -PGR

Slow(Bolac)

100 pl/m² -PGR 40 pl/m² +PGR40 pl/m² -PGR100 pl/m² +PGR100 pl/m² -PGR

100 pl/m² -PGR 100 pl/m² -PGR

Mid(Gregory)

100 pl/m² -PGR 100 pl/m² -PGR 40 pl/m² +PGR40 pl/m² -PGR100 pl/m² +PGR100 pl/m² -PGR

100 pl/m² -PGR

Mid-fast(Lincoln)

100 pl/m² -PGR 100 pl/m² -PGR 100 pl/m² -PGR 40 pl/m² +PGR40 pl/m² -PGR100 pl/m² +PGR100 pl/m² -PGR

Current practice

New practice


Temora 5 October 2011


Improving WUE of early sown wheat• Temora 2011 - very slow maturing variety sown early and managed for high HI yields 0.8-

0.9 t/ha more than current practice• 207 mm GSR• Slow varieties better grain quality (APH) - $35/t premium• Net benefit = $413/ha with less initial expenditure

Grain yield (t/ha) Harvest indexVariety & sow date 40 plants/m² 100 plants/m² 40 plants/m² 100 plants/m²Eaglehawk (15 April) 6.3 6.0 0.41 0.39

Bolac (27 April) 5.9 5.7 0.42 0.39Gregory (9 May) 5.0 5.4 0.44 0.43Lincoln (19 May) 4.8 5.5 0.44 0.44

P-value 0.009 0.018LSD (p=0.05) 0.5 0.01

CV% 9 3


2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

15-Apr 20-Apr 25-Apr 30-Apr 5-May 10-May 15-May

Grai

n yi

eld

(t/h

a)

Sowing date

EaglehawkBolacGregoryLincoln

5%

11%

38%

57%

4%2%

5%

21%

5%2%

4%2%

5%2%

5%

3%

Frost risk of mid-fast varieties prohibitive

All sown at 100 plants/m²

Frost sterility

Sown into good moisture after small April rain

Required irrigation to establish


Junee 2012 - Experimental design

• Low plant densities and defoliation (simulated grazing) to increase HIMaturity class Sowing date

18 April 26 April 8 May 17 MayVery slow (Eaglehawk)

50 pl/m² +defoliate50 pl/m² - defoliate100 pl/m² + defoliate100 pl/m² - defoliate

100 pl/m² -defoliate 100 pl/m² -defoliate 100 pl/m² -defoliate

Slow(Bolac)

100 pl/m² -defoliate 50 pl/m² +defoliate50 pl/m² - defoliate100 pl/m² + defoliate100 pl/m² - defoliate

100 pl/m² -defoliate 100 pl/m² -defoliate

Mid(Gregory)

100 pl/m² -defoliate 100 pl/m² -defoliate 50 pl/m² +defoliate50 pl/m² - defoliate100 pl/m² + defoliate100 pl/m² - defoliate

100 pl/m² -defoliate

Fast(Lincoln)

100 pl/m² -defoliate 100 pl/m² -defoliate 100 pl/m² -defoliate 50 pl/m² +defoliate50 pl/m² - defoliate100 pl/m² + defoliate100 pl/m² - defoliate


Early sown slow maturing wheat managed for HI

• Junee 2012 (177 mm GSR)• Deeper roots, better use of stored soil water and less evaporation• $562/ha increase in gross margin (106%)!

Grain yield (t/ha) 50 plants/m² 100 plants/m²

Variety & sow date Not defoliated Defoliated Not

defoliated Defoliated

EGA Eaglehawk (18 April) 5.9 5.6 6.1 5.4Bolac (26 April) 5.8 5.4 5.5 5.3

EGA Gregory (8 May) 5.1 4.7 5.2 4.6Lincoln (17 May) 4.3 4.1 4.0 4.1

P-value 0.034LSD (p=0.05) 0.3


3.5

4.0

4.5

5.0

5.5

6.0

6.5

15-Apr 20-Apr 25-Apr 30-Apr 5-May 10-May15-May20-May

Grai

n yi

eld

(t/h

a)

Sowing date

Eaglehawk

Bolac

Gregory

Lincoln

LSD (P=0.05)

“There are only two times to sow – on time or early”- Peter Ridge

Junee 20135%

6%

28%

45%

5%

3%

14%12%

5%4%

11%

7%

3%

8%

4%

7%

Frost damage %


What about low rainfall? - Condobolin 2011

• Stress during late winter and spring reduced grain number• Yields comparable

Grain yield (t/ha) Harvest index (%)Variety & sow date 30 plants/m² 90 plants/m² 30 plants/m² 90 plants/m²

Eaglehawk (15 April) 3.4 3.1 0.37 0.32Bolac (27 April) 3.3 2.9 0.38 0.35Gregory (5 May) 3.6 3.2 0.44 0.39Lincoln (16 May) 2.8 3.0 0.46 0.45

Axe (25 May) 2.1 2.6 0.45 0.44P-value 0.029 0.027

LSD (p=0.05) 0.4 0.02CV% 10.5 3.4


What about low rainfall? - Condobolin 2012

• Higher dry matter offset by low HI• Yield advantage not as large in low rainfall environments but still

worthwhile!

35 plants/m² 80 plants/m²Variety & sow date Un-defoliated Un-defoliated Defoliated

EGA Eaglehawk (19 April) 3.2 2.6 2.7Bolac (30 April) 3.4 3.5 3.2

EGA Gregory (9 May) 3.4 3.0 2.8Lincoln (18 May) 3.0 2.6 3.0

P-value <.001LSD (p=0.05) 0.4


Bolac – sow early for yield AND quality

12-Apr 17-Apr 22-Apr 27-Apr 02-May07-May12-May17-May22-May0.0

1.0

2.0

3.0

4.0

5.0

6.0

Temora Lake Bolac

Sowing date

Scre

enin

gs (%

)


Why do early sown crops yield more?

• Deeper roots• Less evaporation• Longer yield formation phase


Junee 2012 - roots 1.65-1.75 m depth

Eaglehawk sown 18 April Lincoln sown 17 May


Deeper roots = more water extraction


Less evaporation = higher WUE

Variety & sowing date

Water-use (mm)

Total dry matter (kg/ha)

WUE for dry matter

(kg/ha.mm)

Transpiration (mm)

Evaporation (mm)

Eaglehawk 18 April 345 11756 34 214 132Bolac 26 April 348 12556 36 228 120Gregory 8 May 344 9798 28 178 166

17 May 321 9229 29 168 153


Less evaporation = higher WUE

Gregory 100 plants/m² sown 15 April Gregory 100 plants/m² sown 19 May

Both photos taken 29 June 2010


Longer yield formation phase

Eaglehawk 15 April

Lincoln 19 May

0 50 100 150 200 250

Series1 Sowing-Z31 Z31-Z69

Days after 15 April


Yield driven by growth during stem elongation

Lake Bolac

Temora

Condobolin

Photo of site at anthesis


Temora 7 October 2011 – Eaglehawk 40 plants/m² sown 15 April20 spikelets per head


Temora 7 October 2011 – Lincoln 100 plants/m² sown 19 May16 spikelets per head


Benefits increase at farm level (CSIRO modelling, Julianne Lilley)

Strategy1. Mid-fast varieties only – sowing window opens 5

May2. Very slow + mid-fast variety – sowing window opens

10 April

LocationAverage

farm wheat yield (t/ha)

Paddock yields <1.0

t/ha (%)

Average farm wheat yield (t/ha)

Paddock yields <1.0

t/ha (%)

Years in which very

slow variety planted (%)

Average area of very slow

variety planted (%)

Condobolin 1.5 48% 2.2 34% 71% 59%

Temora 2.9 22% 3.8 14% 78% 66%

Kerang 2.1 35% 3.0 22% 49% 37%

Lake Bolac 4.5 4% 5.0 5% 98% 84%

Morchard 1.6 44% 2.3 32% 29% 19%


Increasing whole-farm wheat yield – 20 day program

15-Apr 20-Apr 25-Apr 30-Apr 5-May 10-May 15-May 20-May 25-May3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

GregoryBolac

Sowing date

Grai

n yi

eld

(t/ha

)

Start

Finish

Average yield = 4.7 t/ha

Start

Finish

Average yield = 5.5 t/ha

Very slow + mid-fast varieties

Mid-fast variety only


Putting it into practice

• Sow winter wheats late February – late April (watch WSMV)• Revenue tablelands• Wedgetail slopes• Wylah, Whistler, Rosella western plains

• Sow slow maturing spring wheats from ~10 April to late April• Bolac, Eaglehawk, Forrest

• Must have stored soil water and be sure crop will emerge!!!• Use shovel to check soil is wet to at least 30 cm• Pick paddocks that don’t need a good knock-down• Some diseases are exacerbated by early sowing, consider control options• Drop seeding rates on high N paddocks

• If it doesn’t rain, start dry-sowing main-season varieties in late April


Case study – medium rainfall zone• Tony Lehmann, Illabo• Bolac sown 15 April 2011 (John Deere disk reduces vigour, increases HI)• Yield 5.5 t/ha 13.5% protein


Wedgetail sown 2 April 201180 mm rain April-August200 sheep for 8 weeks (50 Ha)

Yield 2.2 t/ha(CLF_Justica in next paddock with same history yielded 1.7 t/ha)

Matt Curtis – 35 km west of MilduraAverage annual rain 275 mm

Photo and data courtesy Michael Moodie


Case study – medium rainfall zone

• David Kingston, The Rock NSW• Bolac sown 20 April 2012• 4.0 t/ha, 1% screenings• Main season wheat 3.0 t/ha• Won district crop competition• (Photo taken 6 July 2012 Chris

Minehan RMS consulting)


What about canola?

• Dual-purpose canola experiments un-grazed yields (John Kirkegaard, CSIRO & Kalyx)

• Young 2010• How early is too early?

Grain yield (t/ha)Crop 10 March (S1) 22 March (S2) 6 April (S3) 15 April (S4)Taurus (winter) 4.0 3.4 3.6 3.646Y78 (spring) 3.7 3.4 2.9 3.6

Sustainable Agriculture FlagshipJames HuntResearch Scientistt +61 2 6246 5066e [email protected] www.csiro.au

SUSTAINABLE AGRICULTURE FLAGSHIP

Thank you


Protein (%)

• Very low soil N at sowing (56 kg/ha N to 1.8 m)• 370 kg/ha urea (165 kg/ha N) top-dressed

• 210 kg/ha July• 160 kg/ha August

• Still not enough to make APH in highest yielding treatments!

Grain yield (t/ha) 50 plants/m² 100 plants/m²

Variety & sow date Not defoliated Defoliated Not

defoliated Defoliated

EGA Eaglehawk (18 April) 11.0 11.3 11.2 10.0Bolac (26 April) 12.7 12.3 12.8 13.1

EGA Gregory (8 May) 11.9 12.1 12.8 12.4Lincoln (17 May) 13.9 13.3 14.7 14.3


What about high rainfall? - Lake Bolac 2011

27-Apr 02-May 07-May 12-May 17-May4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

Sowing date

Gra

in y

ield

(t/h

a) Derrimut

Water limited yield potential - Py = (water-use – 60)*22

Bolac

Lincoln


What about high rainfall? - Westmere 2012

16-Apr 21-Apr 26-Apr 01-May 06-May 11-May 16-May 21-May6.0

6.5

7.0

7.5

8.0

8.5

9.0

Forrest Bolac Derrimut Lincoln

Sowing date

Grai

n yi

eld

(t/h

a)

LSD (p=0.05)

Establishment poor at first time of sowing - 58, 96, 103 and 122 plants/m²(target 160 plants/m²)


What about high rainfall? - Inverleigh 2012

4.0

4.5

5.0

5.5

6.0

6.5

26-Apr 01-May 06-May 11-May 16-May 21-May 26-May 31-May

Grai

n yi

eld

(t/h

a)

Sowing date

Forrest Bolac Derrimut Lincoln

LSD (p=0.05)

Increasing whole-farm wheat yield and reducing risk through early sowing

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