Responding to shifts in climate, water and environment

Take home messages

• The irrigated areas of inland south east Australia are getting warmer and drier. This trend will continue which will present some challenges and opportunities.
• Significant shifts in water management, crops and practices have occurred and will continue as water availability will vary and its value increase.
• Irrigators have work to do to secure a widespread social licence to use water.
• Crop water productivity can improve.
• The future can be better, but it will be different.

Summary

Having lived and worked in Griffith from 1980 until 1998, I was part of the rapidly changing setting that is water use in the southern Murray Darling Basin (MDB). The very substantial changes in water ownership, water distribution, irrigation practice and commodity mix that were gaining pace during that time are now obvious. In this presentation my intention is to identify several of the large-scale influences that are and will continue to affect irrigated cropping in the Riverina and Murray regions. There is the opportunity to reflect on the very evident changes in climate and highlight some consequences for water and crops. Change in water management continues to be extremely challenging and it is instructive to revisit some settings from the early 2000s to identify what shifts are occurring. A focus on water productivity at the crop scale shows that improvement is still possible. Finally, thinking about the longer term, I will illustrate that adaptation to the multiple social, economic, environmental and resource drivers is possible especially through regional scale land use adjustment.

Water in the Murray Darling Basin

The below long term average annual rainfall during 2002 to 2009 (the Millennium drought) in the MDB appears to be repeating from 2012 - broken only by the preceding three years of above average rainfall that recharged major storages. Unfortunately, the long-range forecasts for late winter and spring for the remainder of 2019 are mostly at or below average rainfall.

I noted, in a 2007 summary on the water and irrigation situation in the MDB that:

• the demand for water from all users will increase,
• there will be less total water available for irrigation,
• more research was needed to find the best mix for community, environment and production outcomes, and;
• water productivity improvement was possible provided distribution and application systems were upgraded, water trade was encouraged, policy supported more profitable enterprises and irrigators link with the rivers through environmental service to ensure their access into the future.

The first three of these four provisions have mostly occurred, but the irrigator link to the rivers that greatly increases the chances of an ongoing social licence to use water is far from established.

I offer the following four principles that should apply to water management in the MDB:

1. It’s a complex system, so:
   • there will never be simple, single or perfect fixes,
   • we cannot control, only influence, and;
   • any ‘fix’ will need adjusting, refining or replacing as we learn.
2. Increasing water use efficiency will increase demand, so:
   • a rigorous audit before and after change is imperative, and;
   • the focus needs to be on productivity (including environmental) with efficiency only as a collateral benefit.
3. Within any time period, the water resource is finite.
4. Forget ‘balance’ – negotiate trades and honestly face the consequences of managing within the limits of the resource and the time.

Figure 1 shows the shift in irrigation water diverted for different crops in the MDB.

Figure 1. Comparison of water diverted for different crops in the MDB in 2007 and 2014 (Australian Bureau of Statistics)

The comparison (Figure 1) between two years, seven years apart illustrates:

• Water use on pastures (grazed and cut) remained substantial.
• Available water was greater in 2013/14 to enable more rice.
• Cotton expansion was a standout.
• Perennial fruit and nut crops increased, but not hugely.
• Vegetable and grapevine water use remaining relatively small.

Observed shifts in irrigated areas and practices

1. The southward expansion of cotton has been substantial:
   • There is greater reliability of water, displacing rice and cotton is more profitable.
   • Cotton varieties are now more cold tolerant, insect and disease resistant.
   • Mean temperature is increasing – early season soil temperatures are warmer!
2. The area of perennial crops (nuts, fruit and vines) is increasing:
   • Water demand will increase as will the water price.
   • However – this sector only uses 16% of total water in MDB (2013/14) but is likely to increase its proportional use.
3. There is an increasing proportion of informed and adaptable irrigators:
   • Education and know-how standards have improved.
   • There is much increased technology use – enabled through better communication and social media.
   • There are greatly improved water supply and control systems.
   • There is more capital input, with notably better machinery.

Learning from the recent past

In 2005 a comprehensive study was coordinated entitled ‘The Irrigation Industry in the Murray and Murrumbidgee Basins’ (Meyer, 2005). Most of the information in that study was aggregated from census data taken in 2000/01 while current data is mostly from 2013/14. In 2000/01, the Murray and Murrumbidgee regions had a population of 533 000, a number that is unlikely to have changed greatly since then. The area irrigated was estimated at 1.2 million hectares spread over an estimated 25,000 farms. Current figures for the MDB indicate that the irrigated area represents 1.56 million hectares associated with 14,500 businesses. While the areas being compared are not exactly the same, the indications are quite clear – there has been considerable consolidation to larger irrigated businesses and shifts in commodities being grown with some new areas being irrigated and mostly replacing some that are no longer irrigated.

Despite not having an updated estimate of on-farm irrigation assets it is instructive to compare the water asset. In 2000/01 the water asset was estimated at $6.66 billion for the Murray and Murrumbidgee. With the current water volume of 8 071 GL valued at $4 million/GL the asset value is $32.3 billion.

When examining irrigated areas, it is worth restating that the economic and social data illustrate that irrigated regions support more communities relative to rain fed areas that have annual rainfall of less than 500mm. These latter areas simply cannot generate sufficient economic activity to support substantial populations.

Increasing water productivity

A few studies done in the early 2000s on a range of irrigated crops consistently showed a very large range of water productivity among producers. For example, Armstrong et al (2000) measured water use productivity of dairy farms from less than 30kg milk product/ML water to more than 100kg milk product/ML water. To their credit, the rice industry tracked its productivity over several decades and showed that with both increased yields and more controlled water management that water productivity (measured as grams of grain per kilogram of water used) had increased. As indicated earlier, a focus on water productivity, rather than water use efficiency per se is a much more informative and engaging way of considering the alternative uses of water.

Adapting to a changed future

No-one should be in any doubt that the near and mid-term future is going to be quite different to the present. Many of the drivers of change are essentially outside of our influence, let alone our control. World population growth, limits to increased resources, unstable trade and economic settings, social expectations and climate change are looming examples. Positioning ourselves so that we are adaptable should be an imperative for all regional planning. To this end, a program called ‘Adapted Future Landscapes’ (Bryan et al 2011) has been developed that aims to develop process and information tools to assist regions plan and adapt to change. The idea is to explore future land use options and the consequences and then to have these options embedded in regional planning with community support. Much time was spent in community engagement to find out what people really wanted which was used to design an information and analysis tool that could help with future planning processes. Two regional example areas showed that there were lots of possible combinations of land use that would maintain economic and social viability as well as meet conservation and productivity goals. The exercise showed that it is possible to design a land and resource use system within a region that would give a very good chance of adapting to a changed and better future, but it would be different to that which exists now. Many people and organisations find this both exciting and scary.

Useful resources

Bryan, B.A., Connor, J., Meyer, W., Crossman, N.D., King, D., McNeill, J., Wang, E., Barrett, G., Ferris, M.M., Morrison, J.B., Pettit, D., Freudenberger, D., O’Leary, G.J., Fawcett, J., Elmahdi, A., Doble, R., Stenson, M., Walker, G., Jolly, I.D., Pickett, T. and Dalby, P.R. (2007).  Lower Murray Landscape Futures. Vol 1, Executive Summary.  Land Technology Alliance, Adelaide.

Bryan, B.A., Crossman, N.D., King, D., McNeill, J., Wang, E., Barrett, G., Ferris, M.M., Morrison, J.B., Pettit, C., Freudenberger, D., O’Leary, G.J., Fawcett, J. and Meyer, W. (2007).  Lower Murray Landscape Futures, Vol II, Analysis of Regional Plans and Landscape Futures for Dryland Areas.  Land Technology Alliance, Adelaide.

Bryan, B.A., Crossman, N.D., King, D., McNeill, J., Wang, E., Barrett, G., Ferris, M.M., Morrison, J.B., Pettit, C., Freudenberger, D., O’Leary, G.J., Fawcett, J. and Meyer, W. (2007).  Lower Murray Landscape Futures, Vol III, Data Analysis, Modelling and Visualisation for Dryland Areas.

Meyer, Wayne (2018). Water and the Murray Darling Basin. Agricultural Science 30:1 p74 – 75.

Meyer, Wayne S. (2018). Increasing water productivity in agriculture: an overview. Ch. 21, Water Management V1. Oweis, T. (ed.), Water management for sustainable agriculture, Burleigh Dodds Science Publishing, Cambridge, UK (ISBN: 978 1 78676 176 7;)

Meyer, Wayne S. (2014). Irrigation in Transition – Changing Purpose, Policy, Infrastructure and Practice for Greater Productivity. Ch.3 (p. 29 – 44) in “Technological innovations in irrigation engineering: Impacts on climate change, water quality and transfer of technology”. Eds. Silvio Carlos Ribeiro Vieira Lima, Francisco de Souza, Manoel Valnir Junior, Jose Antonio Frizzone, Hans Raj Gheyi. Fortaleza, CE Brazil: INOVAGRI, 2014. 278p. il, 15.5 x 21.0 cm. ISBN 978-85-67668-04-8

References

Armstrong, DP, Knee, JE, Doyle, PT, Pritchard, KE, Gyles, OA (2000). Water-use efficiency on irrigated dairy farms in northern Victoria and southern New South Wales. Australian Journal of Experimental Agriculture. 40: 643 – 653.

Bryan, B.A., Crossman, N.D., King, D. and Meyer, W.S. (2011). Landscape futures analysis: assessing the impacts of environmental targets under alternative spatial policy options and future scenarios.  Environmental Modelling and Software 26, 83-91.

Meyer, W.S. (2005).  The Irrigation Industry in the Murray and Murrumbidgee Basins.  CRC for Irrigation Futures Technical Report No 03/05.  June 2005.  143pp. Accompanying brochure – “Irrigation in Perspective Irrigation in the Murray and Murrumbidgee Basins a bird’s eye view” CRC for Irrigation Futures and CSIRO Water for a Healthy Country. Aug 2005. 16pp.

Contact details

Wayne S Meyer
University of Adelaide, School of Biological Sciences,
PMB 1, Glen Osmond SA 5064
08 8313 8110
wayne.meyer@adelaide.edu.au