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

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?

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.

•Less compaction

•More yield

•Less screenings•better drainage

•better soil health

•less tractor capital

•lower input costs•smoother running

•less fuel use

LOWER COSTSBETTER 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

BENEFITSOF CTF

~ $50/ha in 2000

Photo courtesy of Andrew Whitlock Precision Agriculture

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 controlBiology and shrinkage does the rest

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 ONLY WHEELS ONLY

CRUMBY

Less fuel use and greenhouse gas

emissions

Total benefit /ha

have autosteer

no

autosteer$36 $45

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

ll

0

10

20

30

40

50

60

70

80

90

100

1t/ha 1.2t/ha 1.4t/ha 1.6t/ha 1.8t/ha 2t/ha 2.2t/ha 2.4t/ha

$/ha

Ben

efit

Current yield

Benefits From CTF (10% yieild increase and 2.5% shift to better grade)

$350/t

$300/t

$250/t

$200/t

$150/t

Large potential benefits for

• High rainfall areas• High rainfall years• Years with high

prices

• Each farm needs individual calculation

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)

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

Searching for new evidence in 2012

• Deep ripped sand• No controlled traffic• Measure winter cone resistance• Measure yield and quality• Sample unwheeled and wheeled• Simplified calculation of CTF benefits

1 2 3 4 5 6 7 8 9 10 11 1220 0 2 0 0 87 84 137 0 5 53 196 8340 0 213 327 70 258 411 212 67 271 164 554 16360 40 333 312 199 265 509 310 225 308 179 613 15780 150 287 227 209 298 499 415 375 494 201 432 171

100 209 275 187 192 428 673 810 616 973 347 401 342120 239 336 197 662 1304 686 1576 1069 3172 973 679 929140 260 463 229 799 1744 707 2809 1981 4169 2188 1564 2324160 264 536 316 1516 2652 658 4203 3583 4460 4690 2730 3633180 215 615 470 1901 3271 629 5182 5709 5105 4787 3503 3874200 140 672 1781 2361 3556 586 5431 6179 5052 3817 3971220 88 640 2453 3153 3681 626 5467 6000 5072 4002 3881240 78 690 3074 3980 3626 1594 5266 6378 5072 4025 3693260 95 822 3681 4685 3508 1989 4668 6317 4957 3941 3562280 142 1391 3712 5167 3384 2998 4690 6177 4740 3882 3381300 1033 2476 4540 5272 3234 3854 4479 5931 4511 3691 3198320 2373 3578 4716 5289 3194 4267 4878 5643 4334 3555 3096340 3514 4347 4619 5012 2997 4335 4714 5573 4375 3361 2984360 4255 4494 4458 4810 2773 4312 4819 5466 4348 3230 2824380 4639 4396 4486 4630 2613 4188 4495 5073 4181 3101 2620400 4672 4319 4207 4264 2521 3904 4458 4847 3923 3009 2477420 4603 4463 4215 3872 2480 3608 4118 4637 3722 2870 2305440 4614 4443 4056 3546 2442 3402 3963 4525 3516 2667 2238460 4382 4172 3892 3362 2374 3226 3704 4288 3338 2503 2109480 4089 3962 3766 3263 2284 3039 3666 4060 3222 2392 2025500 3789 3961 3600 3118 2244 2983 3561 3645 3084 2311 1997520 3521 3989 3406 3004 2215 2920 3376 3581 2920 2274 1997540 3376 3691 3171 2796 2232 2781 3219 3469 2775 2186 1891560 3114 3312 2977 2587 2245 2657 3073 3306 2665 2105 1803580 2890 3197 2915 2442 2252 2679 3008 3238 2600 2100 1776600 2720 3221 2859 2456 2161 2647 2984 3232 2492 2107 1687620 2505 3167 2685 2452 1980 2495 2997 3216 2436 2118 1626640 2321 3049 2560 2436 1821 2418 3001 3254 2414 2104 1555660 2258 2921 2529 2391 1764 2442 3025 3192 2383 2112 1550680 2170 2879 2414 2387 1821 2402 3034 3204 2279 2101 1517700 2020 2747 2258 2416 1942 2352 2970 3263 2196 2064 1462720 1950 2594 2119 2346 1925 2260 2881 3182 2205 1990 1413740 1859 2537 1955 2258 1855 2183 2694 3057 2244 1951 1375

SUBSOIL CONSTRAINT WARNING!

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

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

How CTF benefits were calculated

yield (t/ha)2.0 NT mean

1.64t/ha

1.0

SEEDER WIDTH

Spray Spray

Seed Seed HarvestHarvest

CTF yield<UNWHEELED YIELD>

Location Buntine (B West)Date deep ripped 2010 in pastureWheat variety/sowing date/ GS rainfall mm Mace/9 th June/120Yield of unwheeled, t/ha 1.90Yield 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) 0.5/0.25/0.5/0.5Gross normal traffic yield, t/ha

1.64Total** yield increase from CTF, kg/ha (%) 158 (9.6)

MEASUREMENT SITES

$- $100,000 $200,000 $300,000 $400,000 $500,000 $600,000 0123456789

10

3%Nabawa 4.9%Binnu 8.6%Buntine 9.6%15%

Cost of moving to CTF

Repa

ymen

t pe

riod

for c

osts

(y

ears

)

discsknife points

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

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.

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

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

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)

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.

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

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)

yield value lost by residual wheelings

Poor growth from residual compaction

Wheat at a CTF farm at

BuntineCurrent 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

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

Seed Hawk prototype model of the 1300 (~70t fully loaded) expected to be available for sale in late 2013

The future is coming!

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

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

30t Seismic survey trucks Mingenew 2006

Deeper compaction of sand by higher axle loads

100

90

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60

50

40

30

20

10

00 1 2 3 4 5 6

dep

th, c

m

penetration resistance, MPa

unclayed bush clayed in a wet summer

100

90

80

70

60

50

40

30

20

10

00 1 2 3 4 5 6

dep

th, c

m

penetration resistance, MPa

unclayed bush clayed in a wet summer SoG Trk Ys Trk

7t average axle load

15t axle load x 6

Carry grader Seismic trucks

Restricts root growth to 35-45 cm

Deep compaction limits yield more on deep sands than loams(using YieldProphet with NAR soils in 2005 season)

0.0

0.5

1.0

1.5

2.0

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3.0

0 20 40 60 80 100 120 140

pred

icte

d gr

ain

yiel

d, t

/ha

max depth of root growth, cm

YIELDS FOR UNRESTRICTED ROOT GROWTHROOTS

LIMITED TO 600mm

LOAM yield unchanged

Loss of ~1t/ha for

SAND

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

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.

AcknowledgementsRoss 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’