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Wayne Pluske

Equii

Make the complex simple to make more money, make life easier and ideally both

Focus on soils, nutrition and fertiliser

Also chair of Soil Constraints – West Steering Committee

GRDC Soil Constraints – West Steering Committee

“looks after GRDC’s investment into soil constraints in the western region”

- ensure there is bang for the investment buck- provide guidance, feedback, direction on projects- check projects are integrated- make subtle recommendations to project leaders- make bigger recommendations to GRDC- do a pretty good job

Soil Constraints - West Steering Committee


- RCSN Kwinana East representative (Bob Nixon)

- RCSN Kwinana West representative (Tony White)

- RCSN Geraldton representative (Craig Topham)

- RCSN Albany representation (Mark Pearce)

- RCSN Esperance representation (Quentin Knight)

- Western Panel Representative (John Even)

- GRDC Manager (Julia Easton)

- Chair (Wayne Pluske)


Recurring items:

- the usuals:- more trials in more places in more seasons …………………- why are they doing that and not this?

- better extension of results- better economic analysis of results- better integration of information into my farming system and farming business

Economics of tackling subsoil constraints

Or how robust is the balance sheet?

Certain and large investment is needed, yet yield benefits are uncertain

because many “tech” things affect the financial outcome of subsoil amelioration

How does one justify the cost and risk?

How does one assess likely returns and risk to justify investment?

Economics of tackling subsoil constraints - how do we justify cost and risk?

- Business are good at “looking for the edge” - some can be good edges, others not so good edges

- Businesses are good at managing financial risk

Researchers and others are not good at quantifying returns and risk in a meaningful way

Economic analyses are always “done the wrong way, irrelevant to me, too simple, too complicated, modelled so not real, ………….”

When we say we need more economic analysis, what does this actually mean?

Tackling subsoil constraints – meaningful return:risk info?

- Simplistic economic analysis of trial results

- Returns on one single variable input

- Multiply “chance” results by dollars to get big dollar differences

- Different perspectives from researchers, management consultants, agronomists, agribusiness advisers, bankers, ……………

- Short term cash flow v longer term profitability

- How to prioritise where to tackle subsoil constraints (accurate diagnosis and expectations of benefits of amelioration)

- How to know it relates to my country and my management

- How to measure if it works

The eleven agricultural soil zones of south-western Australia

Economic analysis of the impacts and management of subsoil constraints Dr Elizabeth (Liz) Petersen

Economist, Department of Agriculture and Food, Western Australia

NPV ($/ha) Benefit cost ratio Annual profit ($/ha) Break even (years)

Soil type TD TD & DB TD TD & DB TD TD & DB TD TD & DB

Sandy earths 799 (670) 990 (890) 3.7 (3.2) 5.5 (5.7) 64 (54) 79 (72) 3 (6) 3 (6)

Clays & shallow loamy duplexes

745 (540) 860 (670) 3.8 (2.9) 4.8 (4.1) 60 (43) 69 (54) 3 (6) 3 (6)

Deep loamy duplexes & earths

750 (540) 860 (670) 3.8 (2.9) 4.7 (4.1) 60 (43) 69 (54) 3 (6) 3 (6)

Alkaline shallow duplex

1,030 (730) 1,150 (940) 4.3 (3.1) 5.5 (5.3) 83 (59) 92 (76) 3 (7) 3 (5)

Deep sandy duplexes

890 (n.a.) 1,060 (n.a.) 3.9 (n.a.) 5.7 (n.a.) 71 (n.a.) 85 (n.a.) 3 (n.a.) 3 (n.a.)



Subsoil acidity - economic analysis over 20 yearsIF pH < 4.5IF pH < 5.0

Benefit cost ratio

DR & DW alone DR & DW + gypsum DR & DW + CTF

0.6 0.2 4.8

Subsoil compaction- economic analysis over 20 years

Beacon: 2015 and 2016Benefit to cost ratio = (sum of benefits from year 1 and 2 – cost)/cost

Thanks to Wayne Parker, DAFWA

York gum Nil lime 5 t/ha lime

R300 R450 R450P Nil R300 R450 R450P Nil

2015 -3.1 0.6 0.0 0.0 -0.6 -1.0 0.0 -0.7

2016 -5.7 -1.2 -0.6 0.0 -0.7 -1.2 0.1 -0.5

Morrell Nil gypsum 5 t/ha gypsum

R300 R450 R450P Nil R300 R450 R450P Nil

2015 -4.1 -3.8 -0.7 0.0 -1.5 -1.8 -0.9 -4.9

2016 -3.0 -3.7 0.7 0.0 -1.4 -1.9 -0.6 -4.8

Tackling subsoil constraints – practical issues

- Soil type changes - mainly talking about parts of blocks or paddocks rather than whole blocks/paddocks

- Figuring out if there are subsoil constraints, what they are and where they start and finish

- Having confidence amelioration will work and make money

- Kill many birds with one stone? “I might as well tackle everything at once”

- Where do we start? What paddock, what gear, ……………

Tackling subsoil constraints – good diagnostics

- Spatial information: yield maps, google earth, shouldertop computer, NDVI, EM, radiometrics, …..

- Hotspots of weeds? Ryegrass and/or radish

- Shovel- Is it “tough” digging?- How deep are roots?- Do roots go sideways? Especially radish- Non-wetting?

Tackling subsoil constraints – practical issues post amelioration

- Groundcover or lack thereof

- Uneven seedbed

- Hotted up herbicides (less OC, higher pH, herbicide movement)

- Poor establishment, poor vigour, poor competitiveness and/or poor herbicide tolerance

- Induced nutrient deficiencies

- Droughting that may not otherwise occur

Subsoil Constraints: Understanding and management - David Hall

From David Hall - DPIRD

Summary of 2016 trials (many established before 2016)


Greener plots are 10 – 20 t/ha manure trenched in

2015 Esperance – proof of concept


0.16 t/ha yield increase in 20150.15 t/ha yield increase in 2016

2015/16 Esperance – grower practices

Topdown


2015 Burracoppin

Large strip trial


2016 Burracoppin

Plot trial

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

Nil lime 2.5 t lime 5 t lime Nil lime 2.5 t lime 5 t lime Nil lime 2.5 t lime 5 t lime Nil lime 2.5 t lime 5 t lime

Can

ola

yie

ld (

t/h

a)

No cultivation Disc plough Deep rip Disc plough + Deep rip

LSD at 0.001 probability level

2015 Merredin RS

Plot trial


Depth of Ripping and Tyne Design (2016ES47) – fibre optic cable layingDavid Hall , Andrew Heinrich (Farm and General) , Steve Lloyd


Depth of Ripping and Tyne Design (2016ES47)David Hall , Andrew Heinrich (Farm and General) , Steve Lloyd

All treatments Main treatments


Depth of tillage effects on deep sandplain soils – DandaraganChris Wilkins and Bill Bowden (West Midlands Group)

Large scale ripping trial Small plot ripping x N trial

46 N/ha applied at weeks:


Interaction of cultivation and lime, west Wubin 2016

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

3.00

Control Limesand Dolomite Lime +Dolomite



Mac

e w

he

at y

ield

(t/

ha)

LSD

No till Spader Grizzly

Best net margin two years in a row

Acidity (pH < 5.5) Multiple constraints

Constraints maps include:Acidity, Alkalinity, Boron toxicity, Salinity, Sodicity, Compaction, Non wetting, Waterlogging, Erosion

Source: Dennis van GoolFrom David Hall - DPIRD

Innovative approaches in managing subsoil acidity

GRDC Project DAW0252 (2016-2021)

Project Manager: Chris Gazey

DPIRD Researchers: Dr Gaus Azam and Dr Craig Scanlan

UWA Researchers: Prof Zed Rengal and Paul Demon

From Chris Gazey - DPIRD

1. Pot trial: Effects of different soil ameliorants on acidic wodjil subsoil and establishment of Al sensitive barley crop

• Subsoil only (from Kalannie)• Al sensitive crop barley only (La Trobe)• Five rates of lime x five rates of gypsum (total treatments 25) – replicated and randomised• Direct seeding of barley seeds• Grow for three weeks after germination• Measure soil pH, EC and Al (all in CaCl2 1:5 extract) and soil solution at field capacity • Measure root morphology at three weeks

Research questions:- Which ameliorant(s) is more effective to increase soil pH and reduce toxic Al?- Does lime + gypsum work better than a single ameliorant?- What happens if we bring subsoil to the top (as in MBP) and treat for acidity related issues?- How is the establishment of an Al sensitive crop (barley) affected by ameliorations?


2. Pot trial: Effects of different soil ameliorants on sub and mixed acidic soil and crop establishment

• Subsoil and mixed soil (50:50) (from Kalannie)• Three crops (wheat, barley and canola)• Five rates of lime with and without gypsum (total treatments 10) – replicated and

randomised• Direct seeding of seeds• Grow three weeks after germination• Measure soil pH, EC and Al (all in CaCl2 1:5 extract) and soil solution at field capacity • Measure root morphology at three weeks

Research questions:- How much lime do we need to correct acidic soil profile?- Does lime + gypsum work better than a single ameliorant?- What happens if we mix equal proportions of subsoil and topsoil along with the optimum

amount of soil ameliorant?- How is the establishment of common crops affected by ameliorations?


Treatments:Soils: low and high topsoil pHLime: 0, 3, 6 t/haGypsum: 0, 1.5, 3 t/ha Rainfall: 200 & 400 mm (divided into 12 applications)

Column size and count: 500 x 100 mm; 108 columnsMonthly measurement of pH, Al, Ca, S at 5 depths using soil solution extracted by Rizons

Objective: Estimate individual and combined effects of lime and gypsum at varying rates

Research questionsDoes initial soil pH influence movement of alkalinity into acidic subsoil?Do intensity and total annual rainfall affect movement of alkalinity into to acidic subsoil?Does combination of lime and gypsum works better in ameliorating acidic subsoil?

3. Column experiment - Hydro-chemical amelioration of subsoil acidityNortham Growth Room


Objective: Estimate individual and combine effects of lime and gypsum at varying rates

Treatments:Lime: 0, 2, 4, & 6 t/ha / 0 & 4 t/haGypsum: 0, 1, 2 & 3 t/ha / 0 & 2t/ha (may be repeated in future years)Incorporation: no incorporation & one-way ploughingSoil compaction will be pre-treated with deep ripper

Design: Split plot Latin square: (4x4x2) with 3 replicates / (2x2x2) with 5 replicatesPlots size and count: 20 x 1.82 m; 96 plots / 50 x 13 m; 40 plotsMeasurements: pH, Al, Ca, S at depths (in soil solution and alternative extract); plant response (growth and yield)

4 & 5. Field trials - Interactive effect of lime & gypsum towards amelioration of subsoil acidityKalannie – small plots and large plots


Objective: Minimise subsoil acidification using nitrate fertilizer in combination with lime

Treatments:Lime: plus & minus limeN sources: ammonium sulphate & calcium nitrateN placement: surface & banded at 10 cmK: plus & minus K

Design: RCBD (2x2x2x2) with 4 replicatesPlots size and count: 20x1.82 m; 64 plotsMeasurements: pH, Al, nutrients (in soil solution and alternative extract); plant response (growth and yield)

6. Field trials - Biological amelioration of subsoil acidity Merredin, Wongan Hills


Objective: Minimise subsoil acidification using different sources of N fertilizer in combination with lime

Treatments:1. Control (40N Urea TD)2. Lime + 40N Urea TD3. Lime + 40N CaNO3 TD4. Lime + 40N Urea DB5. Lime + 40N CaNO3 DBTD=topdressed; DB=banded at 10 cm

Design: RCBD with four replicatesPlots size and count: 1 x 1.2 m micro-plots; 15 plotsMeasurements: pH, Al, nutrients, root distribution using Rhizotron tubes; plant response (growth and yield)

7. Field trial - Effect of lime and nitrogen fertiliser source on root growth in an acid subsoil Wongan Hills


Objective: Estimate changes in subsoil pH under different cropping sequences and lime application rates

Treatments:Crop sequence: continuous wheat and wheat/fallowTillage: no cultivation & cultivation in 2016 with offset discsLime rate: 0, 2, 4 & 6 t/ha limesand applied before cultivation in 2016

Design: RCBD (2x2x4) with four replicatesPlots size and count: 20x1.54 m; 64 plotsMeasurements: pH, Al, nutrients (in soil solution and alternative extract); plant response (growth and yield

8. Field trial - Effect of cultivation and fallow on the rate of change of subsoil pH after lime applicationMerredin


Glasshouse trials using large Rhizoboxes for root measurements under different levels of ameliorations mainly by deep-ripping

Research objectiveto characterise the factors influencing root and shoot growth responses to slotting a curtain of ameliorated top/sub soil into acidic subsoil

9 . Collaboration with UWA


wayne pluske equii - rcsngrowernetwork.net.au/uploads/5/4/2/8/54288593/pluske... · 2018. 10....

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