1. General Model Information

Name: SUNDIAL

Acronym: SUNDIAL

Main medium: terrestrial
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: ordinary differential equations
Main application:
Keywords: soil, decomposition, plant, plant debris, animal debris, organic matter

Contact:

Nicola Bradbury & Jo Smith

Soil Science Department, IACR-Rothamsted, Harpenden, GB
phone: +44 1582 763133
fax: +44 1582 760981
email: nicola.bradbury@bbsrc.ac.uk and josmith@bbsrc.ac.uk

Author(s):

Abstract:

The model simulates the decomposition of soil organic matter.
a) Description of the decomposition of plant and animal debris
Decomposition of plant and animal debris described by a single pool obtained by fitting

b) Description of the decomposition of soil organic matter
Decomposition of soil organic matter described by multiple pools as follows:

BIO

HUM

c) Factors assumed to affect organic matter decomposition

Soil moisture
Clay content
Air temperature

d) Soil layers used in the model
The model divides the soil into 12 layers as follows:

5 cm layers between 0-50cm; 50 cm layers between 50-100 and 100-150cm. Organic matter contained 80% in 0-25cm, 20% in 25-50cm.

MODEL EVALUATION
Sensitivity analyses have been performed as follows:

see Bradbury et al. (1993) in reference list
Model output has been compared to measured data which were independent of the data used in model development
Model output has been compared to measured data quantitatively

Good model performance has been defined by simulated results falling within the standard error or standard deviation of the measured data

Statistical methods are used to determine good model performance. as follows:

see Bradbury et al. (1993) and Whitmore (1991) J.Soil.Sci 42(2): 289-300.

The model has met the criteria for good model performance in the following ecosystems / climatic regions:

Arable ecosystem in a cool temperate climate
see Bradbury et al. (1993) and Jenkinson et al. (1994)

Source of the Abstract: GCTE SOMNET Soil Organic Matter Network Database

II. Technical Information

II.1 Executables:

Operating System(s): DOS 5

II.2 Source-code:

Programming Language(s):

II.3 Manuals:

II.4 Data:

see input/output table for GCTE models

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

a) Weather data used to run the model i) Data type

Rainfall - essential
Air temperature - essential
Evapotranspiration over grass - essential

ii) Temporal resolution of weather data

Weekly - essential

b) Soil data used to run the model

Soil description - desirable
Soil layers - desirable
Soil impermeable layer - essential
Water holding capacity - essential
Clay content - essential

c) Plant and animal inputs used to run the model

Plant nitrogen uptake - desirable
Nitrogen in plant components desirable
Crop yield - essential

d) Land-use and management inputs used to run the model

Crop rotation - timing - essential
Inorganic fertilizer - timing - essential
Inorganic fertilizer - amount - essential
Inorganic fertilizer - type - essential
Organic manure - timing - essential
Organic manure - amount - essential
Organic manure - type - essential
Residue incorporation - timing - desirable
Residue incorporation - amount - desirable
Residue incorporation - type - desirable
Irrigation - timing - desirable
Irrigation - amount - desirable
Atmospheric nitrogen desposition rate

III.2.2 Output

a) Soil outputs

Total carbon
Biomass carbon
Carbon dioxide
Total nitrogen
Biomass nitrogen
Total nitrogen 15
Biomass nitrogen 15
Nitrate
Nitrate nitrogen 15
Ammonium
Ammonium nitrogen 15
Total mineral nitrogen
Total mineral nitrogen 15
Nitrate leaching
Soil water dynamics
Humus C and N, N15 and Residue C and N, N15

b) Plant outputs

Nitrogen removed in agricultural products
Nitrogen uptake by plants
Carbon input to soil in plant debris
Nitrogen input to soil in plant debris
Gaseous losses

c) Animal outputs

d) Other outputs

Denitrification, Volatilization from ammoniacal fertilizers

IV. References

Bradbury, N.J., Whitmore, A.P., Hart, P.B.S. and Jenkinson, D.S.(1993) Modelling the fate of nitrogen in crop and soil in the yearsfollowing application of 15N-labelled fertilizer to winter wheat. J. Agric.Sci., Camb. 121, 363-379.

Bradbury, N.J. and Powlson, D.S. (1994) The potential impact of globalenvironmental change on nitrogen dynamics in arable systems. In: SoilResponses to Climate Change (eds M.D.A. Rounsevell and P.J.Loveland), NATO ASI Series, Springer, Heidelberg.

Jenkinson, D.S., Bradbury, N.J. and Coleman, K. (1994) How theRothamsted Classical Experiments have been used to develop and testmodels for the turnover of carbon and nitrogen in soil. In: Long-termExperiments in Agricultural and Ecological Sciences (eds R.A. Leigh andA.E. Johnston), CAB International.

Smith, J.U., Bradbury, N.J. and Addiscott, T.M. (1995) SUNDIAL:Simulation of Nitrogen Dynamics in Arable Land. A user-friendly,PC-based version of the Rothamsted Nitrogen Turnover model.Agronomy J. (in press).

Whitmore, A.P., Coleman, K.W., Bradbury, N.J. and Addiscott, T.M.(1991) Simulation of nitrogen in soil and winter wheat crops: modellingnitrogen turnover through organic matter. Fertilizer Research 27,283-291.

V. Further information in the World-Wide-Web

GCTE SOMNET Soil Organic Matter Network Database
http://www.res.bbsrc.ac.uk/soils/sundial

VI. Additional remarks

Last review of this document by: T. Gabele : Tue Oct 7 1997
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:50 CEST 2002