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)