Production risks and water use benefits of summer crop production on the south coast of Western Australia
M. J. Robertson A C , D. Gaydon A , D. J. M. Hall B , A. Hills B and S. Penny BA CSIRO Sustainable Ecosystems, Queensland Bioscience Precinct, 306 Carmody Rd, St Lucia, Qld 4067, Australia.
B Western Australia Department of Agriculture, PMB 50, Melijinup Rd, Esperance, WA 6450, Australia.
C Corresponding author. Email: Michael.Robertson@csiro.au
Australian Journal of Agricultural Research 56(6) 597-612 https://doi.org/10.1071/AR04249
Submitted: 27 October 2004 Accepted: 1 April 2005 Published: 24 June 2005
Abstract
Summer crops grown during the summer fallow in a Mediterranean-type climate have the potential to produce out-of-season biomass and grain, increase water use, and reduce deep drainage. The potential effects of growing grain sorghum on components of the water balance, sorghum biomass and grain production, and yield of subsequent wheat crops were investigated by simulation using APSIM and long-term climate data from the Esperance district. Sorghum was simulated as part of 3 systems: (1) as an opportunity crop following wheat harvest, (2) as a fallow replacement after pasture removal and before entering a cropping phase, or (3) as a fallow replacement after a failed or waterlogged winter crop. Simulations were conducted for the period 1957–2003 at Myrup (mean annual rainfall 576 mm), Scaddan (408 mm), and Salmon Gums (346 mm). Sorghum was assumed to have a similar rooting depth to wheat. In order to gain confidence in using APSIM for these investigations, tests were initially conducted against field data involving summer and winter crops in sequence and measurements of soil water dynamics. Data sets also varied in summer rainfall, species (forage sorghum, grain sorghum, Japanese millet), and soil type (deep sand, and medium and shallow duplex).
Overall, the simulations showed that incorporation of a sorghum crop increased transpiration by 10–30 mm/year, made the soil profile drier by a similar amount at wheat sowing, and consequently reduced deep drainage by 3–25 mm/year, depending upon cropping system and location. Long-term average drainage results were dominated by large episodes in wet years. The increased transpiration from the summer crop, although reducing drainage in wet years, could not eliminate drainage. Following wheat yields were reduced by an average of 200–400 kg/ha, corresponding to a reduction of 10% at wetter and 30% at drier locations. In the 2 fallow replacement systems, sorghum biomass was produced in nearly every simulated season. However, averaged over all seasons, sorghum grain production was much less reliable comprising only 10–20% of biomass. In the opportunity system, sorghum produced biomass in only 1 in 3 seasons at Salmon Gums and Scaddan and 1 in 2 at Myrup. Grain was produced in 1 in 5 seasons at all 3 locations, underlining the riskiness of this opportunity niche for summer crops in the Esperance district.
Although summer cropping was shown to result in modest reductions in deep drainage, it also comes at a cost to wheat production. The largest effects on drainage and most reliable biomass production were seen in the systems where the summer crop was grown following pasture removal or a failed (waterlogged) winter crop. This research has also shown that recent farmer and researcher experiences of summer cropping are likely to be more favourably biased towards prospects for summer cropping than indicated by long-term simulations because of their longer-term perspective.
Additional keywords: simulation, deep drainage, sorghum, millet, Esperance, wheat.
Acknowledgments
We thank Owen Brownley (Mt Maddan), Chris Reichstien (Wittenoom Hills), Geoff Tidow (Scaddan), and Ken Degrussa (Neridup) for allowing this research to be conducted on their properties. Excellent technical support was provided by R. Donovan, V. Johnston, and the staff of Esperance Downs Research Station. Funding was provided by the Grains Research and Development Corporation, Department of Agriculture Western Australia, and CSIRO Sustainable Ecosystems.
Angus, JF (1991). The evolution of methods for quantifying risk in water limited environments. ‘Climatic risk in crop production: models and management for the semi-arid tropics and subtropics’. (CAB International: Wallingford, UK)
Asseng S,
Fillery IRP,
Anderson GC,
Dolling PJ,
Dunin FX, Keating BA
(1998a) Use of the APSIM wheat model to predict yield, drainage, and NO-3 leaching for a deep sand. Australian Journal of Agricultural Research 49, 363–378.
| Crossref | GoogleScholarGoogle Scholar |
Asseng S,
Keating BA,
Fillery IRP,
Gregory PJ,
Bowden JW,
Turner NC,
Palta JA, Abrecht DG
(1998b) Performance of the APSIM-wheat model in Western Australia. Field Crops Research 57, 163–179.
| Crossref | GoogleScholarGoogle Scholar |
Asseng S,
Fillery IRP,
Dunin FX,
Keating BA, Meinke H
(2001) Potential deep drainage under wheat crops in a Mediterranean climate. 1. Temporal and spatial variability. Australian Journal of Agricultural Research 52, 45–56.
| Crossref | GoogleScholarGoogle Scholar |
Dolling PJ,
Fillery IRP,
Ward PR,
Asseng S, Robertson MJ
(2005a) Consequences of rainfall during summer–autumn fallow on available soil water and subsequent drainage in annual based cropping systems. Australian Journal of Agricultural Research (In press) ,
Dolling PJ,
Latta RA,
Ward PR,
Robertson MJ, Asseng S
(2005b) Soil water extraction and biomass production by lucerne in the south of Western Australia. Australian Journal of Agricultural Research 56, 389–404.
| Crossref |
Dolling PJ,
Robertson MJ,
Asseng S,
Ward PR, Latta RA
(2005c) Simulating lucerne growth and water use on diverse soil types in a Mediterranean-type environment. Australian Journal of Agricultural Research 56, 503–515.
| Crossref |
Farré I,
Robertson MJ,
Asseng S,
French RJ, Dracup M
(2004) Simulating lupin development, growth and yield in a Mediterranean environment. Australian Journal of Agricultural Research 55, 863–877.
| Crossref | GoogleScholarGoogle Scholar |
Hammer GL, Chapman SC, Muchow RC
(1996) Modelling sorghum in Australia: the state of the science and its role in the pursuit of improved practices. ‘Proceedings of the 3rd Australian Sorghum Conference’. Tamworth, 20–22 February 1996.. (Ed. MA Foale ,
RG Henzell ,
JF Kniepp )
pp. 43–60. (Australian Institute of Agricultural Science: Melbourne, Vic.)
Hills A, Robertson MJ, Gaydon D, Hall D, Lacey T, Ryder A
(2003) Valuation of Sorghum in Western Australia. ‘Solutions for a better environment. Proceedings of the 11th Australian Agronomy Conference’. 2–6 Feb. (
:
)
www.regional.org.au/au/asa.pp.4
Keating BA,
Gaydon D,
Huth NI,
Probert ME,
Verburg K,
Smith CJ, Bond W
(2002) Use of modeling to explore the water balance of dryland farming systems. I. The Murray-Darling Basin, Australia. European Journal of Agronomy 18, 159–169.
| Crossref | GoogleScholarGoogle Scholar |
Keating BA,
Carberry PS,
Hammer GL,
Probert ME, Robertson MJ ,
et al
.
(2003) An overview of APSIM, a model designed for farming systems simulation. European Journal of Agronomy 18, 267–288.
| Crossref | GoogleScholarGoogle Scholar |
Overheu T, Nicholas B, Needham P
(1996) Soil Information Sheet for the Esperance Sandplain. Compiled by Natural Resources Assessment Group, Agriculture Western Australia.
Parkin RJ, Fisher HM
(1969) Grain sorghum production at Esperance, part II. Report on experiments 1968/69. Western Australian Department of Agriculture, Perth.
Probert ME,
Dimes JP,
Keating BA,
Dalal RC, Strong WM
(1998) APSIM’s water and nitrogen modules and simulation of the dynamics of water and nitrogen in fallow systems. Agricultural Systems 56, 1–28.
| Crossref | GoogleScholarGoogle Scholar |
Short R, Salama R, Pollock D, Hatton T, Bond W
(2000) Assessment of salinity management options for Lake Warden Catchments, Esperance, WA: Groundwater and crop water balance modelling. CSIRO Land and Water Technical Report 20/00.
