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

1. Increasing whole-farm wheat yield and reducing risk through early sowing James Hunt, Neil Fettell, Jon Midwood, Paul Breust, Brad Rheinheimer, Annieka Paridaen 27 February 2013 Sustainable Agriculture Flagship

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

3. Recent research on south-east Australian rainfall • Rainfall reductions over Southern Hemisphere semi-arid regions: the role of subtropical dry zone expansion • WenjuCai, 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 • WenjuCai, 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 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

4. Temora moves to Macquarie Marshes!!!! Subtropical ridge has moved 400 km south in April-May April-May rainfall trend since 1951 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

5. Old Junee Apr-May rainfall Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

6. Old Junee Feb-March rainfall Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

8. Winter & spring wheats Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Winter wheat Z69-maturity Z30-Z69 Emergence – Z30 Mid maturing spring wheat Z30-Z69 Emergence – Z30 Z69-maturity Slow maturing spring wheat Emergence – Z30 Z69-maturity Z30-Z69 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 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

9. Sowing and flowering dates Optimal flowering window Wedgetail sowing window (winter wheat) Janz sowing window (early-mid maturing spring wheat Eaglehawk sowing window (slow maturing spring wheat) Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

10. 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 • Riffkinet al. 2003 rain-fed wheat at Hamilton • Stapper & Fischer 1990 irrigated what at Griffith Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

12. Lake Bolac Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

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

15. Sowing times consistent across environments Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

16. Improving WUE of early sown wheat New practice Current practice • Management to improve harvest index • Very low plant density • Plant growth regulators Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

17. Temora 5 October 2011 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

19. Frost risk of mid-fast varieties prohibitive Sown into good moisture after small April rain Frost sterility Required irrigation to establish All sown at 100 plants/m² Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

20. Junee 2012 - Experimental design Low plant densities and defoliation (simulated grazing) to increase HI Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

21. 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%)! Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

22. “There are only two times to sow – on time or early”- Peter Ridge Frost damage % Junee 2013 5% 3% 6% 5% 4% 5% 3% 11% 28% 14% 8% 12% 7% 4% 45% 7% Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

23. What about low rainfall? - Condobolin 2011 Stress during late winter and spring reduced grain number Yields comparable Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

25. Bolac – sow early for yield AND quality Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

26. Why do early sown crops yield more? Deeper roots Less evaporation Longer yield formation phase Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

27. Junee 2012 - roots 1.65-1.75 m depth Lincoln sown 17 May Eaglehawk sown 18 April Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

28. Deeper roots = more water extraction Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

29. Less evaporation = higher WUE Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

30. Less evaporation = higher WUE Both photos taken 29 June 2010 Gregory 100 plants/m² sown 15 April Gregory 100 plants/m² sown 19 May Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

31. Longer yield formation phase Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

32. Yield driven by growth during stem elongation Lake Bolac Temora Condobolin Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

33. Photo of site at anthesis Temora 7 October 2011 – Eaglehawk 40 plants/m² sown 15 April 20 spikelets per head Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

34. Temora 7 October 2011 – Lincoln 100 plants/m² sown 19 May 16 spikelets per head Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

35. Benefits increase at farm level (CSIRO modelling, Julianne Lilley) Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

36. Increasing whole-farm wheat yield – 20 day program Very slow + mid-fast varieties Start Mid-fast variety only Average yield = 5.5 t/ha Start Finish Average yield = 4.7 t/ha Finish Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

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

39. Matt Curtis – 35 km west of Mildura Average annual rain 275 mm Wedgetail sown 2 April 2011 80 mm rain April-August 200 sheep for 8 weeks (50 Ha) Yield 2.2 t/ha (CLF_Justica in next paddock with same history yielded 1.7 t/ha) Photo and data courtesy Michael Moodie Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

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

41. What about canola? Dual-purpose canola experiments un-grazed yields (John Kirkegaard, CSIRO & Kalyx) Young 2010 How early is too early? Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

42. Thank you Sustainable Agriculture Flagship James HuntResearch Scientist t +61 2 6246 5066 e james.hunt@csiro.au w www.csiro.au Sustainable agriculture flagship

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

44. What about high rainfall? - Lake Bolac 2011 Water limited yield potential - Py = (water-use – 60)*22 Bolac Lincoln Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

45. What about high rainfall? - Westmere 2012 Establishment poor at first time of sowing - 58, 96, 103 and 122 plants/m² (target 160 plants/m²) Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

46. What about high rainfall? - Inverleigh 2012 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt