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Simulation of field data by a basic three-dimensional model of interactive root growth


Dunbabin, VM and Diggle, A and Rengel, Z, Simulation of field data by a basic three-dimensional model of interactive root growth, Plant and Soil, 239, (1) pp. 39-54. ISSN 0032-079X (2002) [Refereed Article]

DOI: doi:10.1023/A:1014952728942


Published field data for lupins grown in a deep sandy soil in the wheatbelt of south-western Australia were used to test the predictive ability of a model of three-dimensional root growth. The model has the capacity to simulate the growth of individual root sections in response to the supply and demand for water and nitrate. N mineralisation was not modelled explicitly, but was accounted for through the use of a seasonally variable mineralisation input derived from the field data. Simulated nitrogen and water contents and root length densities in the soil profile agreed well with observed profiles, although all were slightly under-predicted. A sensitivity analysis revealed that model predictions were most sensitive to the drained upper limit values (v/v) and the mineralisationrates (μgN m-3 s-1) incorporated as external inputs to the model, along with the unit rate of N2 fixation (mol nodule-1 s-1) and unit root growth rates (μm mol-1 s-1) which are physiological parameters previously calibrated for lupins. The amount of nitrate leached was predicted well. Spatial plots of nitrate leaching were a close inverse of the root length density plots, with the highest nitrate leaching below the inter-plant zones, and the least nitrate leaching directly below each plant. These results suggest that the root distribution of a legume species such as lupin can have an effect on the leaching of nitrate to depth. It may thus be possible to reduce the total amount of nitrate leached under lupin crops by investigating factors such as the spatial deployment of roots, planting densities and intercropping.

Item Details

Item Type:Refereed Article
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Crop and pasture production
Research Field:Crop and pasture production not elsewhere classified
Objective Division:Plant Production and Plant Primary Products
Objective Group:Grains and seeds
Objective Field:Wheat
UTAS Author:Dunbabin, VM (Dr Vanessa Dunbabin)
ID Code:45082
Year Published:2002
Web of Science® Times Cited:39
Deposited By:Agricultural Science
Deposited On:2007-07-01
Last Modified:2011-11-24

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