New Zealand Journal of Agricultural Research abstracts

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Modelling pastoral farm agro-ecosystems: a review

J. R. Bryant

AgResearch Grasslands Research Centre
Private Bag 11008
Palmerston North 4442, New Zealand
jeremy.bryant@agresearch.co.nz

V. O. Snow

AgResearch Grasslands Research Centre
Private Bag 11008
Palmerston North 4442, New Zealand
val.snow@agresearch.co.nz

Abstract A pastoral farm is a complex agro-ecosystem that produces agricultural outputs such as milk, meat and wool. Detailed consideration of the complexities of agro-ecosystem components, and the interactions between these components, may be best approached with simulation modelling. We reviewed nine simulation models (APSIM, EcoMod, FASSET, GRAZPLAN, GPFARM, Hurley Pasture Model, IFSM, LINCFARM, and WFM) used primarily for research of grazing systems. GrassGro (one of the GRAZPLAN suite of decision support tools), LINCFARM, and WFM had particular strength in their simulation of animal production and farm management. The strengths of APSIM, EcoMod and FASSET lie in their simulation of soil nutrient dynamics, crop or pasture production and spatial variations in soil properties. The Hurley Pasture Model has particular capability to model nutrient cycling in the presence of climate change. The IFSM includes a comprehensive representation of machinery. GPFARM can be used to predict forage production of different plant functional groups.

We suggest that more emphasis could be placed on including the effects of pests and diseases on pasture production and animal performance, more detailed representation of management practices, inclusion of more mechanistic voluntary feed intake and rumen processes and including the effect of specific genes and gene-by-environment interactions on plant quality and yields, nutrient use and animal performance. The Common Modelling Protocol, used in APSIM and the GRAZPLAN suite, may enable the development of a powerful and flexible pastoral agro-ecosystem model which incorporates newly developed modules of the nature mentioned above.

Keywords agriculture; ecosystem; grazing; simulation; whole farm model

A07173; Online publication date 15 August 2008; Received 27 August 2007; accepted 15 April 2008

New Zealand Journal of Agricultural Research, 2008, Vol. 51: 349–363
0028–8233/08/5103–0349 © The Royal Society of New Zealand 2008

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