Michael Cutting1, Tony Hoare2, Tapas Biswas3

1 South Australian Murray-Darling Basin Natural Resources Management Board2 Hoare Viticulture

3 Murray-Darling Basin Authority

Learning on the Run: Adaptive Salinity Management in the South Australian

Lower Murray Region

Irrigation Australia Limited Conference - Adelaide, 2012

Presentation Overview

Study Area

Finniss River

Murray Mouth

Rootzone salinity management study commenced in 2006/07 as a collaboration between the South Australian Research & Development Institute (SARDI) and the SA Murray-Darling Basin Natural Resources Management Board

Water quality was an on-going issue for low yield wine grapes

Since study started significant changes have occurred over the years: water source, water availability, water quality, water taking rules

The presentation will highlight the value that on-going measuring and monitoring can assist on-farm decision making

Project Area (Regional) & Objectives

Study Area

Finniss River

Hindmarsh Island

River Murray

1. How much salt stays within the root-zone from summer irrigation and what is its distribution?

2. How does winter rainfall move salts within the profile?

Project Area (Vineyard) & Statistics

Project Vineyard

Finniss River Variety: Cabernet SauvignonPlanting Year: 2002Water Source: Finniss River/River MurrayIrrigation System: Conventional DripFlow Rate: 1.6L/hrEmitter Spacing: 0.5mRow Spacing: 3mPlant Spacing: 1.5mApplication Rate: 1.1mm/hrSoil Type: Sandy Clay Loam over friable clay with occasional carbonate deposits

Ceramic cupCeramic cup

PVC conduitPVC conduit

Extraction tubeExtraction tube

Rootzone Salinity Monitoring with SoluSAMPLER™™

Sentek TriSCAN™ (www.sentek.com.au)

0.3m0.3m

0.6m0.6m

0.9m0.9m

Rootzone Salinity Monitoring

The Finniss River: Flow vs. Salinity

30/05/2007

01/06/2007

System responds quickly to rainfall in the Eastern Mt Lofty Ranges –

implications for salinity management!

The Finniss River Flow

Irrigation Water Salinity – 2006/07 (Finniss River)

0

1

2

3

4

5

6

7

25

/10

/20

06

8/1

1/2

00

6

22

/11

/20

06

6/1

2/2

00

6

20

/12

/20

06

3/0

1/2

00

7

17

/01

/20

07

31

/01

/20

07

14

/02

/20

07

28

/02

/20

07

14

/03

/20

07

28

/03

/20

07

11/0

4/2

00

7

25

/04

/20

07

9/0

5/2

00

7

23

/05

/20

07

6/0

6/2

00

7

20

/06

/20

07

4/0

7/2

00

7

18

/07

/20

07

1/0

8/2

00

7

Sa

lin

ity

(dS

/m)

Date

0

5

10

15

20

25

30

35

40

45

50

1/07/06 1/09/06 1/11/06 1/01/07 1/03/07 1/05/07 1/07/07 1/09/07

Irrig

atio

n/R

ain

fall

(mm

)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

EC

(d

S/m

) o

r E

To

(m

m)

IrrigationRainfallSoln 30cmSoln 60cmSoln 90cmETo

Big winter rain event

Winter Leaching Irrigation Window

>Drip: water salinity = 5.5 dS/m

Grape threshold salinity Summer Leaching Irrigation

Big summer rain event

Rootzone Salinity - 2006/07

2007/08 - 2010/11: Dry Growing…not by choice!!

March 2008

Finniss River

Impact of 2008 Heat Wave

Rootzone Salinity 2007/08 – 2010/11 (No Irrigation)

High levels of residual salts still observed in 2007/08

Rootzone Salinity - 2011/12

Irrigation water now sourced from River Murray pipeline ~200EC (0.2 dS/m)

259.2mm of rain since 1 May 2012

Rootzone Salinity Trend: 2006/07 – 2011/12

V. Poor WQ – + 6dS/m No irrigation:

4 x seasons

Irrigation resumed ~ 0.2 dS/m

Average rootzone salinity =1dS/m

Average rootzone salinity =10.9dS/m

Lessons & Conclusions

• Monitoring and managing root zone salinity is CRITICAL!

• Summer leaching irrigation largely ineffective in displacing salts beyond the rootzone

• Very low leaching efficiency if water quality is poor

• Winter rainfall holds the key for salt displacement

• Leaching irrigation in winter can leach more salts with less water

• Appears that salinity tolerance is enhanced and greater ability to exclude salt under reduced yield production regime

Acknowledgements

SA MDB NRM Board

Mr. Tony Brooks (Vineyard Owner) - Strangers Reach Vineyard, Finniss SA

SENTEK Sensor Technologies Ltd

Mr. Tim Pitt (SARDI)

Peter Zurcher (ex UniSA)