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Variation in water extraction with maize plant density and its impact on model application

Peake, A. S. and Huth, N. I. and Kelly, A. M. and Bell, K. L. (2013) Variation in water extraction with maize plant density and its impact on model application. Field Crops Research, 146 . pp. 31-37. ISSN 0378-4290

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Article Link(s): http://dx.doi.org/10.1016/j.fcr.2013.02.012

Abstract

The use of maize simulation models to determine the optimum plant population for rainfed environments allows the evaluation of plant populations over multiple years and locations at a lower cost than traditional field experimentation. However the APSIM maize model that has been used to conduct some of these 'virtual' experiments assumes that the maximum rate of soil water extraction by the crop root system is constant across plant populations. This untested assumption may cause grain yield to be overestimated in lower plant populations. A field experiment was conducted to determine whether maximum rates of water extraction vary with plant population, and the maximum rate of soil water extraction was estimated for three plant populations (2.4, 3.5 and 5.5 plants m(-2)) under water limited conditions. Maximum soil water extraction rates in the field experiment decreased linearly with plant population, and no difference was detected between plant populations for the crop lower limit of soil water extraction. Re-analysis of previous maize simulation experiments demonstrated that the use of inappropriately high extraction-rate parameters at low plant populations inflated predictions of grain yield, and could cause erroneous recommendations to be made for plant population. The results demonstrate the importance of validating crop simulation models across the range of intended treatments. (C) 2013 Elsevier E.V. All rights reserved.

Item Type:Article
Business groups:Crop and Food Science
Additional Information:Peake, Allan S. Huth, Neil I. Kelly, Alison M. Bell, Kerry L. Horticulture Australia Dr Craig Henderson, Mr David Schofield and field staff at the Queensland Department of Agriculture, Fisheries and Forestry, Gatton research farm are gratefully acknowledged for managing the field experiments. Mr Daniel Moye is gratefully acknowledged for his dedicated root washing and root scanning work. This research was partially funded by Horticulture Australia. Elsevier science bv Amsterdam
Keywords:Population Root length density Corn APSIM Drought Soil water simulation crop population soil sunflower patterns systems sorghum wheat apsim
Subjects:Plant culture > Field crops > Corn. Maize
Plant culture
Science > Statistics > Simulation modelling
Deposited On:01 Oct 2014 04:13
Last Modified:01 Oct 2014 04:13

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