A comparison of the performance of nine soil organic matter models using datasets from seven long-term experiments

Smith, Peter L.; Smith, Jo; Powlson, D. S.; McGill, W. B.; Arah, J. R. M.; Chertov, Oleg; Coleman, Kevin; Franko, Uwe; Frolking, Steve; Jenkinson, D. S.; Jensen, Lars Stoumann; Kelly, Robert D.; Klein-Gunnewiek, H.; Komarov, Alexander; Li, Changsheng; Molina, J. A. E.; Müeller, Torsten; Parton, William J.; Thornley, J. H. M.; Whitmore, A. P.

doi:10.1016/s0016-7061(97)00087-6

Cited by 984 publications

(646 citation statements)

References 34 publications

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“…The change of one variable (temperature, precipitation or CO 2 ) at a time only was considered in order to investigate single factor effects. The set of statistical methods suggested by Smith et al (1997) was used to evaluate the performance of SPACSYS on the observed variables.…”

Section: Methodsmentioning

confidence: 99%

Modelling the impact of environmental changes on grassland systems with SPACSYS

Wu¹,

Whitmore²,

Bellocchi³

2015

Advances in Animal Biosciences

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Section: Methodsmentioning

confidence: 99%

Modelling the impact of environmental changes on grassland systems with SPACSYS

Wu¹,

Whitmore²,

Bellocchi³

2015

Advances in Animal Biosciences

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“…When the studies used did not provide the analyzed oP and non-phytate P (NPP) contents of their diets, then their oP and NPP contents were estimated (Sauvant et al, 2004). The statistical package MODEVAL v1.1 developed by Smith et al (1997) was used for the purposes of model evaluation in a series of statistical tests to assess their goodness-of-fit. (1) The correlation coefficients (r) is used to assess whether simulated values followed the same pattern as observed values, with the value of unity being the best fit.…”

Section: Sensitivity Analysesmentioning

confidence: 99%

Modelling phosphorus intake, digestion, retention and excretion in growing and finishing pig: model evaluation

Symeou

Leinonen

Kyriazakis

2014

Animal

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A deterministic, dynamic model was developed, to enable predictions of phosphorus (P) digested, retained and excreted for different pig genotypes and under different dietary conditions. Before confidence can be placed on the predictions of the model, its evaluation was required. A sensitivity analysis of model predictions to ±20% changes in the model parameters was undertaken using a basal UK industry standard diet and a pig genotype characterized by British Society Animal Science as being of 'intermediate growth'. Model outputs were most sensitive to the values of the efficiency of digestible P utilization for growth and the non-phytate P absorption coefficient from the small intestine into the bloodstream; all other model parameters influenced model outputs by <10%, with the majority of the parameters influencing outputs by <5%. Independent data sets of published experiments were used to evaluate model performance based on graphical comparisons and statistical analysis. The literature studies were selected on the basis of the following criteria: they were within the BW range of 20 to 120 kg, pigs grew in a thermo-neutral environment; and they provided information on P intake, retention and excretion. In general, the model predicted satisfactorily the quantitative pig responses, in terms of P digested, retained and excreted, to variation in dietary inorganic P supply, Ca and phytase supplementation. The model performed well with 'conventional', European feed ingredients and poorly with 'less conventional' ones, such as dried distillers grains with solubles and canola meal. Explanations for these inconsistencies in the predictions are offered in the paper and they are expected to lead to further model development and improvement. The latter would include the characterization of the origin of phytate in pig diets. Keywords: mathematical model, phosphorus, phytate, pig, sensitivity analysis ImplicationsThe model developed in the companion paper (Symeou et al., 2014) and evaluated here predicts adequately the P digestion, retention and excretion of growing-finishing pigs for a wide range of dietary compositions and for pigs of different genotypes. Consequently, the model can be applied to develop feeding strategies to optimize phosphorus (P) utilization and minimize the different forms of P excreted to the environment. The model can be further improved, by considering 'reactive' as opposed to total phytate content of the diet, as well as experimentally establishing the net efficiency of digestible P utilization for growth and the non-phytate P absorption coefficient from the small intestine into the bloodstream, for pigs offered access to different diets.

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“…The above mentioned model components in SoilGen have a good verification status (c.f. Addiscott & Wagenet, 1985;Smith et al, 1997;Jalali & Rowell, 2003;Dann et al, 2006;Jabro, Jabro, & Fox, 2006;Finke & Hutson, 2008). Ideally, the calibrated model is verified at independent test locations in the study area as well.…”

Section: Pedogenesis Modelmentioning

confidence: 99%

On the use of integrated process models to reconstruct prehistoric occupation, with examples from Sandy Flanders, Belgium

et al. 2010

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A major problem in palaeolandscape reconstruction is that basic data useable for inference are scattered in both the temporal and spatial sense. To improve the understanding of occupational patterns by means of landscape reconstruction methods, we propose the application of different process-models in the soil-water-landscape reconstruction in an interdisciplinary approach. These process-models include a digital elevation model, a hydrological model, a pedogenesis model and a land evaluation model. Due to the multiple disciplines involved, no single model can be used but a model framework is defined in which the various discipline-specific models are integrated. In this paper, each of these models is explained and illustrated for a case-study in Flanders (Belgium) and difficulties occurring when integrating the different models, e.g. grain, extent, coverage, are discussed.

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A comparison of the performance of nine soil organic matter models using datasets from seven long-term experiments

Cited by 984 publications

References 34 publications

Modelling the impact of environmental changes on grassland systems with SPACSYS

Modelling the impact of environmental changes on grassland systems with SPACSYS

Modelling phosphorus intake, digestion, retention and excretion in growing and finishing pig: model evaluation

On the use of integrated process models to reconstruct prehistoric occupation, with examples from Sandy Flanders, Belgium

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