1. General Model Information

Name: ORYZA_W 2.1 - Rice model for irrigated and water-limited conditions.

Acronym: ORYZA_W21

Main medium: terrestrial
Main subject: agriculture
Organization level: ecosystem, population
Type of model: not specified
Main application:
Keywords: crop growth, rice, irrigation, rainfed, lowland, upland, drought stress, biomass, Et, seepage, percolation, water content


Dr.ir. B.A.M. Bouman.
Research Institute for Agrobiology and Soil Fertility (AB-DLO), Dept. Agrosystems Research, P.O.Box 14, 6700 AA Wageningen, THE NETHERLANDS.
Phone: +31.317.475972
Fax: +31.317.423110
email: b.a.m.bouman@ab.dlo.nl



The model simulates growth and development of rice in irrigated and rainfed lowland and in rainfed upland conditions, with ample supply of nutrient and with no pests, diseases or weeds. The above-ground part of the model is based on ORYZA1*, extended with the effects of drought stress on crop growth and development. Daily dry matter increase is simulated based on underlying physical and physiological processes (e.g. light interception, leaf and canopy photosynthesis, maintenance respiration (e.g. light interception, leaf and canopy photosynthesis, maintenance respiration, conversion). Leaf photosynthesis is a function of irradiation and leaf nitrogen content. Soil evaporation and crop transpiration are calculated on the basis on the Penman equations. Drought stress effects include leaf rolling, delay in phenological development, inhibited leaf growth and reduced photosynthesis. Switches are used to control the production environment. In lowland, the above-ground module is combined with the water balance model LOWBAL*, and in upland with SAHEL. In irrigated lowland, irrigation is treated as dynamically simulated variable. ORYZA_W can be used for experimental studies (leaf area index as forcing function; comparison with measurements) and for extrapolation purposes (e.g. agro-ecological zonation, scenario studies).

Purpose of the model:

Model parentage: ORYZA_W* (1.0), ORYZA1*, SUCROS*, MACROS*, and INTERCOM*.

Source of the AbstractCAMASE Register of Agro-ecosystems Models

II. Technical Information

II.1 Executables:

Operating System(s): VAX computers, IBM compatible PC/AT >= 640 Kb RAM. Contract necessary: Costs: : Dfl. 270,=. Comments:

II.2 Source-code:

Programming Language(s): Microsoft FORTRAN-77 (in FSE*).

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

Rate variables: Above ground: phenological development, leaf and canopy photosynthesis (gross, net), maintenance and growth respiration, crop growth, growth of plant organs, evaporation, transpiration (and others); Below-ground: seepage and percolation rate, water content, irrigation.

State variables: Above ground: biomass (total, and per crop organ e.g. leaf, stem, root, ear), leaf area index, intercepted light (and others); Below-ground: ponded water depth, content and amount of water in puddled layer.

III.2.1 Input

Geographical latitude and longitude, weather data (daily radiation, minimum and maximum temperature), wind speed, rainfall, vapour pressure), crop specific physiological and morphological properties, physical and hydrological soil properties, crop and soil management information.

III.2.2 Output

Crop rate and state variable (e.g. leaf area index, soil cover, biomass), soil rate and state variables (e.g. ponded water depth, irrigation water).
Basic spatial unit: m2 - ha.
Time interval of simulation: 1 day.

IV. References

Bouman, B.A.M., 1993. ORYZA_W, Rice growth model for irrigated and water-limited conditions. SARP report, March 1993. AB-DLO. 67 pp.
Bouman, B.A.M., 1994. ORYZA_W rice growth model. SARP Internal paper, April 1994. (45 pp.) [Formal description to appear in 1994]

V. Further information in the World-Wide-Web

  • Methane Emissions from Rice in Asia with Climate Change
  • ORYZA_0
  • ORYZA 1

    VI. Additional remarks

    Parentage: ORYZA_W (1.0),ORYZA1, SUCROS , MACROS , and INTERCOM.
    Last review of this document by: Fri Sep 26
    Status of the document:
    last modified by Joachim Benz Mon Jul 2 18:31:37 CEST 2007

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