We have started updating the documentation. Finished chapters are linked to the list of content below. For chapters not yet updated, relevant sources of information are listed.


Soil Plant Atmosphere System Model

Technical Description

Editors: M.E. Styczen, P. Abrahamsen, M. Holbak and E. Diamantopoulos


List of content

1. System and modelling concepts

2. Weather and reference ET

3. Surface processes

4. Water flow in soils

General info: Daisy description
Macropores, Holbak et al. (2021)
Drainage 1D/2D, Mollerup et al. (2014)
3 domain system, Hansen et al. (2012b), D3_2_safir
Root water uptake, Hansen and Abrahamsen (2009)

5. Heat transport

6. Solute transport

General info:  Daisy description
Macropores/Matrix, Holbak et al. (2021)
Drainage 1D/2D, Mollerup et al. (2014)
3 domain system, Hansen et al. (2012b), D3_2_safir

7. Mineral Nitrogen

General info:  Daisy description, Hansen et al. (1991)

8. Pesticide transport

9. Soil organic matter model

General info: Hansen et al. (1991), Hansen et al. (2012a)
Document on initialisation of SOC pools in Daisy

10. Crop model

General info:  Daisy description
Root water uptake, Hansen and Abrahamsen (2009)
Hansen et al. (2012a)

11. System management model

General info:  Daisy description
Hansen et al. (2012b)

12. Integrated model

Hansen et al. (2012a)
Abrahamsen and Hansen (2000)


  • Abrahamsen, P and Hansen, S. (2000): Daisy: an open soil-crop-atmosphere system model. Environmental Modelling & Software 15: 313-330.
  • Hansen, S. and Abrahamsen, P. (2009). Modeling water and nitrogen uptake using a single-root concept: Exemplified by the use in the Daisy model. In: Quantifying and Understanding Plant Nitrogen Uptake for Systems Modeling. Ed. by Liwang Ma, Lajpat R. Ahuja, and Thomas W. Bruulsema. CRC Press, pp. 169-195
  • Hansen, S., Abrahamsen, P., Petersen, C.T., and Styczen, M. (2012a). Daisy: Model use, calibration and validation. ASABE 55 (4): 1315-1333. 
  • Hansen, S., Petersen, C. T., Mollerup, M.1, Abrahamsen, P., Gjettermann, B., Nielsen, M.H., Styczen, M., Poulsen, R., Lørup, J.K., Yamagata, K. and Butts, M. (2012b). Flerdimensional modellering af vandstrømning og stoftransport i de øverste 1-2m af jorden i systemer med markdræn. Bekæmpelsesmiddelforskning fra Miljøstyrelsen nr. 138
  • Hansen, Søren, Henry E. Jensen, Niels Erik Nielsen, and Henrik Svendsen (1990). DAISY - Soil Plant Atmostphere System Model. Tech. rep. A10. Miljøstyrelsen.
  • Hansen, S., Jensen, H.E., Nielsen, N.E. and Svendsen, H. (1991). Simulation of nitrogen dynamics and biomass production in winter wheat using the Danish simulation model DAISY. Fertilizer Research 27: 245-259, 1991.
  • Holbak, M., Abrahamsen, P., Hansen, S., Diamantopoulos, E., 2021. A physically based model for preferential water flow and solute transport in drained agricultural fields. Water Resources Research 57, e2020WR027954. https://doi.org/10.1029/2020WR027954
  • Jansson, P.E., Halldin, S., 1980. Soil water and heat model. Technical description. (Technical Report No. 26), Coniferous Forest Project. Dept. of Ecology and Environment Research. Swedish University of Agricultural Sciences, Uppsala, Sweden.
  • Mollerup, M., Abrahamsen, P., Petersen, C.T., Hansen, S., 2014. Comparison of simulated water, nitrate, and bromide transport using a Hooghoudt-based and a dynamic drainage model. Water Resources Research 50, 1080–1094. https://doi.org/10.1002/2012WR013318
  • Plauborg, F., Abrahamsen, P., Gjettermann, B., Mollerup, M., Iversen, B.V., Liu, F., Andersen, M.N., Hansen, S., 2010. Modelling of root ABA synthesis, stomatal conductance, transpiration and potato production under water saving irrigation regimes. Agricultural Water Management, SAFIR - Safe and high quality food production using low quality waters and improved irrigation systems and management 98, 425–439. https://doi.org/10.1016/j.agwat.2010.10.006
  • van der Keur, P., Hansen, S., Schelde, K., Thomsen, A., 2001. Modification of DAISY SVAT model for potential use of remotely sensed data. Agricultural and Forest Meteorology 106, 215–231. https://doi.org/10.1016/S0168-1923(00)00212-4