The Lower Burdekin Delta (LBD) is located on the dry-tropical coastal strip in North Queensland,Australia. The region is Australia's largest sugar producing area with approximately 38,000 hectares of landunder sugarcane. However, the LBD also borders the Great Barrier Reef World Heritage Area (GBRWHA).Thus industry, community, and federal, regulatory and environmental organisations are interested inascertaining the magnitude of nitrate leaching from the root zone and potential implications for theGBRWHA. Direct measurement of nitrate leaching is problematic, thus it is likely that modelling will play anever-increasing role in guiding experimental work and decision-making. The difficulty in monitoring nitrateleaching also raises concerns with respect to capturing data for the purpose of calibrating and verifyingmodels. However, other crop/soil parameters that directly affect the amount of nitrate leaching are morereadily measured (e.g., soil hydraulic properties, matric potential, crop yield, fertilizer application timing, andinitial soil N). Thus, parameterising/calibrating a model to such data raises the expectation that associatedmodel outputs related to nitrate leaching will be useful. We used APSIM (Agricultural Production SystemsSimulator), with constituent crop-growth, soil-water, and nitrogen transformation modules (Sugar, APSIMSWIM,Soiln2) to model the 2001/2002 sugarcane ratoon crop at Kalamia, field 48, within the LBD andfound the measured and modelled soil water nitrate loads at 1.5 m depth to be of a similar order. This resultsuggests that the modelled nitrate leaching values are likely to be indicative of the magnitude of nitrateleaching that occurs under field 48. Subsequent sensitivity analyses identified the timing and mode offertilizer application as key parameters over which management control might be exploited to minimise theflux of nitrate to groundwater.
|Title of host publication||Integrative Modelling of Biophysical, Social and Economic Systems for Resource Management Solutions|
|Publisher||Modelling and Simulation Society of Australia and New Zealand|
|Number of pages||6|
|Publication status||Published - 2003|
|Event||MODSIM 2003 International Congress on Modelling and Simulation. - Townsville, Queensland, Australia|
Duration: 14 Jul 2003 → 17 Jul 2003
|Conference||MODSIM 2003 International Congress on Modelling and Simulation.|
|Period||14/07/03 → 17/07/03|
Stewart, L., Charlesworth, P. B., & Bristow, K. (2003). Estimating nitrate leaching under a sugarcae crop using APSIM-SWIM. In D. A. Post (Ed.), Integrative Modelling of Biophysical, Social and Economic Systems for Resource Management Solutions (pp. 218-223). Modelling and Simulation Society of Australia and New Zealand.