1. Development of CTF in WA & recent on-farm measurements Paul Blackwell, James Hagan, Steve Davies, Glen Riethmuller, Derk Bakker, Quenten Knight, Dave Hall, Jeremy Lemon, Stanley Yokwe and Bindi Isbister - March 2013

2. 4t 6t WHY CONTROL CROPPING TRAFFIC? These machines do different things on the surface……….. …. but have similar effects on the soil at one foot depth! IS CROPPING TURNING SUBSOILS INTO ROADBASE?

3. MESSAGES 1. Controlled Traffic Farming (CTF) improves the financial returns from cropping most WA soils and has environmental benefits. 2. CTF need not be compromised when increasing seeder width for improved seeding capacity. 3. Future risks of very deep compaction in sands from heavier axle loads can be reduced by CTF.

4. Less compaction More yield Less screenings better drainage better soil health less tractor capital lower input costs smoother running less fuel use LOWER COSTS BETTER INCOME BETTER GROSS MARGIN 1997-2003 WA trials: 7-14% yield increase, less screenings in cereal, more oil in canola, responses on sands, clays, loams and gravels BENEFITS OF CTF ~ $50/ha in 2000 Photo courtesy of Andrew Whitlock Precision Agriculture

5. UNCONTROLLED TRAFFIC SLOW ROOT GROWTH & WATERLOGGING CROP AND WHEELS TRAFFIC PAN CLODDY Most of the evidence we show is for deep sands There is also other WA evidence of CTF benefits on other soil types Sands usually need decompaction in CTF Other soils may only need traffic control Biology and shrinkage does the rest

6. Less fuel use and greenhouse gas production LOW ROLLING RESISTANCE CONTROLLED TRAFFIC FARMING (CTF) SOFT SOIL FOR CROP HARD SOIL FOR WHEELS EASY ROOT GROWTH & DRAINAGE GOOD TRACTION & FLOATATION MORE AERATION & BETTER SOIL HEALTH CROP ONLYWHEELS ONLY CRUMBY Less fuel use and greenhouse gas emissions

7. MIDAS model at 2012 yields & prices, 5% grain yield increase from CTF after deep ripping, 2.5% shift to a better grain grade and 10% reduction of inputs and conservative costs for central wheatbelt farms. recent MIDAS modelling of CTF for 1.2 t/ha grain yield in the central wheatbelt

8. ll Large potential benefits for High rainfall areas High rainfall years Years with high prices Each farm needs individual calculation

9. BARRIERS High costs of machinery changes Other farming system priorities (e.g. weed control, seeding and harvesting capacity) High debt levels No commercial interest (compared to agribusiness promoting VRT & precision agriculture)

10. Technical challenges Narrow widths of lime and straw spreading Windrow burning Wheeltrack erosion Wheeltrack sinkage Training staff (and consultants?) Overland flow control Guidance system compatibility Industry support Seeding and harvesting efficiency

11. Searching for new evidence in 2012 Deep ripped sand Deep ripped sand No controlled traffic No controlled traffic Measure winter cone resistance Measure winter cone resistance Measure yield and quality Measure yield and quality Sample unwheeled and wheeled Sample unwheeled and wheeled Simplified calculation of CTF benefits Simplified calculation of CTF benefits

13. SUBSOIL CONSTRAINT WARNING! It is important to identify any other subsoil constraints than compaction such as acidity, alkalinity, salt and rocks.

14. Extreme compaction conditions Deep ripped 2010 in pasture at BUNTINE Two crops sown and one harvested by July 2012 Crop at 10” spacing Compaction effect on yield narrower than wheel width due to compensatory edge effects

15. How CTF benefits were calculated Spray Seed Harvest CTF yield

16. Location Buntine (B West) Date deep ripped 2010 in pasture Wheat variety/sowing date/ GS rainfall mm Mace/9 th June/120 Yield of unwheeled, t/ha 1.90 Yield in seed/harvest traffic, t/ha (% loss) 0.75 ( 60% ) Yield in spray & seed traffic, t/ha (% loss) 0.38 ( 80% ) wheel widths for seed/spray/harvest/CTF (m) 0.5/0.25/0.5/0.5 Gross normal traffic yield, t/ha 1.64 Total** yield increase from CTF, kg/ha (%) 158 (9.6) MEASUREMENT SITES

17. Analysis of the repayment period for conversion costs for a 2,800ha p.a. of wheat yielding 2t/ha at $250/t and 8.5% interest rate knife points

18. CTF pays off on deep cultivated sands Up to 1.5-4 years are estimated to repay $200,000 conversion with yield benefits. about 50% quicker with grain quality & fuel benefits. The estimate is very sensitive to the calculated traffic patterns and the scale of machinery. Each farm needs individual estimates.

19. How long can deep ripping last? Strips of better crop growth still showed in the stubble from 10 year old deep ripping on a full CTF farm at Binnu

20. The soil in the old rip lines was still soft to excavate it had been protected by the controlled traffic system

21. MESSAGE 1.Controlled Traffic Farming (CTF) improves the financial returns from cropping most WA soils and has environmental benefits. Especially deep sands after deep cultivation (deep ripping, mouldboarding or spading)

22. Are increased seeding capacity and CTF incompatible? The growing dependence on dry seeding in dry autumns and other important seeding windows often sees the prioritisation of seeding capacity (ha/day). Some growers are not adopting, or dis-adopting, CTF to use wider seeders for higher seeding capacity.

23. Effect of speed, tank capacity and seeder width on seeding capacity

24. Possible strategies Use 2 seeders and 2 smaller tractors Double seeder width to use existing tramlines (need to cut off rows/lift tines for paddock edge overlap) Increase seeding speed by wider tines & twin row boots or disc openers. Reduce loading frequency (bigger air cart) Increase loading speed (bigger auger)

25. yield value lost by residual wheelings Poor growth from residual compaction Wheat at a CTF farm at Buntine Current tramline Wheelings off the tramlines by - guidance drift - wider seeder - cross workings Effects of a full or half residual wheeling within a harvesting width wheat Buntine lupins Binnu

26. Possible lost income from residual wheelings $10-20/ha for about a 50% increase of seeder width; depending on season and crop value $5-10/ha for about a doubling of seeder width, but no fit to the existing CTF tramlines Such losses increase over seasons and need comparing to the value of improved seeding capacity

27. Seed Hawk prototype model of the 1300 (~70t fully loaded) expected to be available for sale in late 2013 The future is coming!

28. Will very heavy gear compromise crop profitability? Larger capacity equipment with high axle loads enables improved seeding and harvesting capacity to maximise opportunities and improve efficiency. The risks of very deep compaction from these heavier axle loads need assessment. We examine two interesting cases

29. carry graders claying on the south coast (14t on one axle: loaded)

30. 30t Seismic survey trucks Mingenew 2006

31. Deeper compaction of sand by higher axle loads 7t average axle load15t axle load x 6 Carry grader Seismic trucks Restricts root growth to 35-45 cm

32. Deep compaction limits yield more on deep sands than loams (using YieldProphet with NAR soils in 2005 season) YIELDS FOR UNRESTRICTED ROOT GROWTH ROOTS LIMITED TO 600mm LOAM yield unchanged Loss of ~1t/ha for SAND

33. suggestions Well planned CTF can protect our cropping soils from such deep compaction Curative tillage to 500mm+ can be very expensive Tracks keep loads on tramlines efficiently Undersized duals can aid floatation but minimise compaction

34. MESSAGES revisited 1. Controlled Traffic Farming (CTF) improves the financial returns from cropping most WA soils and has environmental benefits. 2. CTF need not be compromised by increasing seeder width for improved seeding capacity. 3. Future risks of very deep compaction in sands from heavier axle loads can be reduced by CTF.

35. Acknowledgements Ross Kingwell and Amy Fuchsbichler; for crunching the numbers and publishing the paper which re-kindled our interest. Nadine Hollamby (Liebe), Brad West (Buntine), Simon Smart (Nabawa), Graham Harris & Murray Carson (Binnu), Rohan Ford (Balla), Brady Green (Nabawa), Brian McAlpine & Dave Jolly (Buntine), Mark Wilson, Michael O’Callaghan (Dalwallinu) Tim Chamen @controlledtrafficfarming Caring for our Country Project No. OC13-00083: ‘Increasing adoption of reduced cropping traffic’