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RESEARCH ARTICLE

If long fallow cropping is leaky then shallow groundwaters on the Liverpool Plains should be of recent origin

R. R. Young A E , A. Broughton B C , J. M. Bradd D and J. F. Holland A
+ Author Affiliations
- Author Affiliations

A NSW Department of Primary Industries, RMB 944, Calala Lane, Tamworth, NSW 2340, Australia.

B NSW Department of Infrastructure, Planning and Natural Resources, Gunnedah Resource Centre, Curlewis Road, Gunnedah, NSW 2380, Australia.

C Present address: Groundwater Solutions, 115 Tasman Street, Mt Cook, Wellington, New Zealand.

D Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia.

E Corresponding author. Email: rick.young@agric.nsw.gov.au

Australian Journal of Experimental Agriculture 44(10) 1051-1056 https://doi.org/10.1071/EA03133
Submitted: 25 June 2003  Accepted: 19 January 2004   Published: 25 November 2004

Abstract

Previous groundwater studies have indicated that up to 195 000 ha of the Liverpool Plains catchment, south of Gunnedah, New South Wales, Australia, are at risk from shallow saline watertables. Replacement of hydraulically stable, native perennial grasslands with more ‘leaky’ annual cropping systems since the 1950s, particularly long fallow wheat–sorghum rotations, has been held responsible for an apparent increased frequency of shallow watertables and saline discharge. If so, then it follows that shallow groundwater in the alluvium will be recent (less than about 30 years old) and the solution to the problem is a straightforward reduction in deep drainage under farming systems via increased evapotranspiration. However, in this study, we have found levels of bomb pulse tritium in shallow groundwaters that indicate that about half of the shallow groundwaters in the Mooki subcatchment pre-date current agricultural practices. A hypothesis for this unexpected outcome suggests that the problem is complex and that solutions need to be site-specific.


Acknowledgments

We thank Robert Banks and Ian Acworth for helpful discussions regarding the origins of salt and the nature of salinity on the Liverpool Plains; Jane Coram for comments regarding predictive catchment models; Carol and Harry Rose for their determination to sample from even the lowest yielding piezometers; Bob Martin for comments on an earlier draft and Peter Freckleton for production of the map (Fig. 1). Jim McDonald, Des Schroder, John Kneipp and Bob Crouch were instrumental in highlighting and supporting research into resource management issues in the Liverpool Plains catchment in the 1990s. Funds for this study were provided by the Murray–Darling Basin Natural Resources Management Strategy.


References


Abbs K, Littleboy M (1998) Recharge estimation for the Liverpool Plains. Australian Journal of Soil Research 36, 335–357.
Crossref | GoogleScholarGoogle Scholar | open url image1

Acworth RI, Jankowski J (1997) The relationship between bulk electrical conductivity and dryland salinity in the Narrabri formation at Breeza, Liverpool Plains, New South Wales, Australia. Hydrogeology Journal 5, 109–123.
Crossref | GoogleScholarGoogle Scholar | open url image1

Banks R (1995) Soil landscapes of the Curlewis 1:100,000 sheet report. Department of Conservation and Land Management, Sydney.

Banks R (1998) Soil landscapes of the Blackville 1:100,000 sheet report. Department of Conservation and Land Management, Sydney.

Bradd JM, Waite D, Turner J (1994) Determination of recharge/discharge areas and water/salt distribution in aquifers of the Liverpool Plains. Report to the NSW Department of Conservation and Land Management and the Land and Water Resources Research and Development Corporation, UNSW Department of Water Engineering, Kensington.

Broughton A (1994) Mooki River Catchment hydrogeological investigation and dryland salinity studies — Liverpool Plains, New South Wales. Department of Water Resources TS94.026, Barwon Region.

Daniells IG, Holland JF, Young RR, Alston CL, Bernardi AL (2001) Relationship between yield of grain sorghum (Sorghum bicolor) and soil salinity under field conditions. Australian Journal of Experimental Agriculture 41, 211–217.
Crossref | GoogleScholarGoogle Scholar | open url image1

Department of Land and Water Conservation, NSW (1998) ‘The constructed wetlands manual. Volumes 1 and 2.’ (New South Wales Department of Land and Water Conservation: Sydney)

Gates GWB (1980) The hydrogeology of the unconsolidated sediments in the Mooki River Valley, New South Wales. MSc Thesis, University of New South Wales, Australia.

Ingraham NL (1998) Isotopic variations in precipitation. In ‘Isotopic tracers in catchment hydrology’. (Eds C Kendall, JJ McDonnell) pp. 87–118. (Elsevier: The Netherlands)

Paydar Z, Huth NI, Ringrose-Voase AJ, Young RR, Bernardi AL, Keating BA, Cresswell HP, Holland JF, Daniells I (1999) Modelling deep drainage under different land use systems. 1. Verification and systems comparison. In ‘Proceedings of the international congress on modelling and simulation. Vol. 1’. (Eds L. Oxley, F Scrimgeour) pp. 37–42. (University of Waikato: Hamilton, New Zealand)

Ringrose-Voase AJ, Paydar Z, Huth NI, Banks RG, Cresswell HP, Keating BA, Young RR, Bernardi AL, Holland JF, Daniells I (1999) Modelling deep drainage of different land use systems. 2. Catchment wide application. In ‘Proceedings of the international congress on modelling and simulation. Vol. 1’. (Eds L. Oxley, F Scrimgeour) pp. 43–48. (University of Waikato: Hamilton, New Zealand)

Ringrose-Voase AJ, Young RR, Paydar Z, Huth NI, Bernardi AL, et al. (2003) Deep drainage under different land uses in the Liverpool Plains Catchment. NSW Agriculture Report 3, Agricultural Resource Management Report Series, NSW Agriculture, Orange, NSW.

Schroder D, Moore A, Creighton C (1991) ‘Dryland salinity — Liverpool Plains a basin in trouble.’ (Department of Conservation and Land Management: Sydney, NSW)

Stauffacher M, Walker G, Evans R (1997) Salt and water movement on the Liverpool Plains — what’s going on? Land and Water Resources Research and Development Corporation, Occasional Paper No. 14/97, Canberra.

Timms W (1998) Hydraulic linkages between shallow saline groundwaters and pressurised alluvial aquifers on the Liverpool Plains, New South Wales. NSW Department of Land and Water Conservation, Centre for Natural Resources Research Report T2816, Sydney, NSW.

Timms W, Acworth RI, Young RR (2002) Natural leakage pathways through smectite clay: a hydrogeological synthesis of data from the Hudson site on the Liverpool Plains. UNSW Ground Water Centre, Water Research Laboratory Research Report No. 209, Sydney, NSW.

Turner JV, Bradd JM, Waite TD (1991) The conjunctive use of isotopic techniques to elucidate solute concentration and flow processes in dryland salinised catchments. In ‘Proceedings of an international symposium on isotope techniques in water resources development’. pp. 33–59. (International Atomic Energy Agency: Vienna)

URS (2001) ‘Liverpool Plains Catchment Investment Strategy. A report for the Liverpool Plains Land Management Committee.’ (URS Australia Pty Ltd: Hackney, Sth Aus.)

Young RR (1999) Cropping and pasture systems to manage rising watertables and dryland salinity on the Liverpool Plains. Final Report to the Grains Research and Development Corporation on Project DAN 159N, 1993–1999, NSW Agriculture, Orange, NSW.