Deep drainage and land use systems. Model verification and systems comparison
Zahra Paydar A D , Neil Huth B , Anthony Ringrose-Voase A , Rick Young C , Tony Bernardi C , Brian Keating B and Hamish Cresswell AA CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia.
B CSIRO Sustainable Ecosystems/APSRU, 306 Carmody Road, St Lucia, Qld 4067, Australia.
C NSW Department of Primary Industries, Tamworth Agricultural Institute, RMB 944, Calala Lane, Tamworth, NSW 2340, Australia.
D Corresponding author. Email: Zahra.Paydar@csiro.au
Australian Journal of Agricultural Research 56(9) 995-1007 https://doi.org/10.1071/AR04303
Submitted: 10 December 2004 Accepted: 24 June 2005 Published: 28 September 2005
Abstract
Deep drainage or drainage below the bottom of the profile usually occurs when rain infiltrates moist soil with insufficient capacity to store the additional water. This drainage is believed to be contributing to watertable rise and salinity in some parts of the Liverpool Plains catchment in northern New South Wales. The effect of land use on deep drainage was investigated by comparing the traditional long fallow system with more intense ‘opportunity cropping’. Long fallowing (2 crops in 3 years) is used to store rainfall in the soil profile but risks substantial deep drainage. Opportunity cropping seeks to lessen this risk by sowing whenever there is sufficient soil moisture. Elements of the water balance and productivity were measured under various farming systems in a field experiment for 4 years in the southern part of the catchment. The experimental results were used to verify APSIM (Agricultural Production Systems Simulator) by comparing them with predictions of production, water storage, and runoff. The verification procedure also involved local farmers and agronomists who assessed the credibility of the predictions and suggested modifications. APSIM provided a realistic simulation of common farming systems in the region and could capture the main hydrological and biological processes. APSIM was then used for long-term (41 years) simulations to predict deep drainage under different systems and extrapolate experimental results. The results showed large differences between agricultural systems mostly because differences in evapotranspiration contributed to differences in profile moisture when it rained. The model predicted that traditional long fallow farming systems (2 crops in 3 years) are quite ‘leaky’, with average annual deep drainage of 34 mm. However, by planting crops in response to the depth of moist soil (opportunity or response cropping), APSIM predicted a much smaller annual drainage rate of 6 mm. Opportunity cropping resulted in overall greater water use and increased production compared with long fallowing. Furthermore, modelling indicated that average annual deep drainage under continuous sorghum (3 mm) is much less than under either long fallow cropping or continuous wheat (39 mm), demonstrating the importance of including summer cropping, as well as increasing cropping frequency, to reducing deep drainage.
Acknowledgments
We thank Robert and Edwina Duddy for use of the research site on Hudson. We gratefully acknowledge funding from the Land and Water Research and Development Corporation, the Grains Research and Development Corporation, and Salt Action. Interpolated long-term weather data were supplied by the Queensland Centre for Climate Applications and the Bureau of Meteorology (http://www.dnr.qld.gov.au/silo/datadril.html).
Abbs K, Littleboy M
(1998) Recharge estimation for the Liverpool Plains. Australian Journal of Soil Research 36, 335–357.
| Crossref | GoogleScholarGoogle Scholar |
Bradd JM
(1994) Determination of recharge/discharge areas and water/salt distribution in aquifers of the Liverpool Plains. Report to NSW Conservation and Land Management and Land and Water Resources Research and Development Corporation, University of New South Wales, Department of Water Engineering, Kensington.
Broughton, A (1994).
Greiner R
(1994) Economic assessment of dryland salinity in the Liverpool Plains. Project Report, University of New England, Armidale, NSW.
Isbell, RF (1996).
Hayman PT
(1992) Using 100 years of Gunnedah rainfall data to investigate the role of pasture in reducing water table recharge. ‘Proceedings, Grassland Society of NSW, 7th Annual Conference’. Tamworth, 8–9 July 1992. (The Grassland Society of NSW: Orange, NSW)
Jeffrey SJ,
Carter JO,
Moodie KB, Beswick AR
(2001) Using spatial interpolation to construct a comprehensive archive of Australian climate data. Environmental Modelling and Software 16, 309–330.
| Crossref | GoogleScholarGoogle Scholar |
Jones, CA ,
and
Kiniry, JR (1986).
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 |
Keating BA, McCown RL, Cresswell HP
(1995) Paddock-scale models and catchment scale problems: The role for APSIM in the Liverpool Plains. ‘Proceedings of the International Congress on Modelling and Simulation. Vol. 1: Agriculture, Catchment Hydrology and Industry’. 27–30 November 1995. (Ed. P Binning ,
H Bridgman ,
B Williams )
pp. 158–165. (The University of Newcastle: Newcastle, NSW)
Littleboy M,
Silburn DM,
Freebairn DM,
Woodruff DR,
Hammer GL, Leslie JK
(1992) Impact of soil erosion on production in cropping systems. I. Development and validation of a simulation model. Australian Journal of Soil Research 30, 757–774.
| Crossref | GoogleScholarGoogle Scholar |
Paydar Z, Gallant JC
(2003) Applying a spatial modelling framework to assess land use effects on catchment hydrology. ‘Proceedings of International Congress on Modelling and Simulation MODSIM 2003, Integrative Modelling of Biophysical, Social and Economic Systems for Resource Management Solutions’. 14–17 July 2003, Townsville, Qld. (Ed. DA Post )
pp. 491–495. (Modelling Simulatuuion Society of Australia and New Zealand Inc.: Canberra, ACT)
Ringrose-Voase AJ, Young RR, Paydar Z, Huth NI, Bernardi AL
(2003) Deep drainage under different land uses in the Liverpool Plains Catchment. Agricultural Resource Management Report No. 3, NSW Agriculture.
Ritchie JT
(1972) Model for predicting evaporation from a row crop with incomplete cover. Water Resources Research 8, 1204–1213.
Stauffacher M, Walker GR, Evans WR
(1997) Salt and water movement in the Liverpool Plains — What’s going on? Land and Water Resources Research and Development Corporation Occasional Paper No. 14/97, Canberra, ACT.
USDA (1972).
