ABSTRACT
Modelling crop growth and yield in palm oil cultivation Christopher Teh Boon Sung, Universiti Putra Malaysia, Malaysia; and Cheah See Siang, Sime Darby Research Sdn. Bhd., Malaysia
1 Introduction
2 Theory and model development
3 Modelling meteorology
4 Modelling photosynthesis
5 Modelling energy balance
6 Modelling soil water flow
7 Modelling crop growth
8 Model testing
9 Results and discussion
10 Conclusion
11 Where to look for further information
12 Acknowledgement
13 List of main symbols
14 References
The first semi-mechanistic oil palm model was OPSIM (van Kraalingen, 1985). It was developed by taking into account some aspects of oil palm physiology and the physical processes and causal relationships between the environment and crop. OPSIM was modified by Gerristma (1988) in order to propose a more rigorous approach to estimate oil palm photosynthesis and later by Dufrêne et al. (1990), whose model (SIMPALM) relied much more on measured data of oil palm vegetative parameters. GPHOT, GPHOT2, OPLFSIM3 and later OPRODSIM (Henson, 1989, 2000, 2004, 2009) were the most comprehensive models at that period, as Henson’s models progressively improved by including increasingly more effects and factors of oil palm growth and yield, including modelling the seasonal cycles of oil palm yield. Supplementary factors such as the effects of air vapour pressure deficit and available soil water on oil palm photosynthesis were also modelled. Fitted relationships, based
Modelling crop growth and yield in palm oil cultivation
cultivation
on measured data collected from various oil palm studies, were later included to better estimate oil palm root turnover, dry matter partitioning and flower sex ratios. Since then, the development of new oil palm models, such as WaNuLCAS (van Noordwijk et al., 2011), ECOPALM (Combres et al., 2013) and PALMSIM (Hoffmann et al., 2014) have increased in frequency. More recent oil palm models such as APSIM-Oil Palm (Huth et al., 2014), CLMPalm (Fan et al., 2015) and CLIMEX-Oil Palm (Paterson et al., 2015) are actually components of a larger, more general modelling framework. The APSIM-Oil Palm, for instance, is one of the 30 sub-models for various crops, trees and pastures under the APSIM model framework.
