ORYZA: A crop growth simulation model for rice

ORYZA version 3 is an ecophysiological model which simulates growth and development of rice including water, C, and N balance (Bouman et al., 2001; IRRI, 2013) in lowland, upland, and aerobic rice ecosystems. It works in potential, water-limited, nitrogen-limited, and NxW-limited conditions. And it was calibrated and validated for 18 popular rice varieties in 15 locations throughout Asia.

Since 2009, ORYZA2000 has been modified from a crop model toward a cropping model aimed mainly at abiotic stress. The modeling group in International Rice Research Institute encourages tests and applications of ORYZA ver.3 and welcomes feedback. The modeling group also provides minor tech support to users.


The model development

Following the “School of de Wit”, ORYZA ver. 3 evolved from its earlier versions (ORYZA2000 v2.13, v2.12, v2 and v1), which are the integrated successors of ORYZA1 (Kropff et al., 1994), ORYZA_W (Wopereis et al., 1996) and ORYZA_N (Drenth et al., 1994). ORYZA2000 v2.12 and V2.13 were respectively integrated into cropping system models APSIM and DSSAT as APSIM-ORYZA (2005) and DSSAT-ORYZA (2012) to handle rice simulations in different cropping systems.


Current status and capabilities

ORYZA now has extended range of application from single to multiple rice crop simulations. Comparing ORYZA ver.3 and v2.x , ORYZA ver.3 generates outputs that include effects coming from combined irrigation water management options, interacting water and N uptake, soil carbon and nitrogen dynamics, nitrogen balance based on N-fertilizer management , organic fertilizer input, daily minimum and maximum temperature, soil temperature, plant density, rice root growth, climatic and abiotic stresses, greenhouse gas (CO2 and N2O), and plant responses to drought and nitrogen deficiency stresses. ORYZA ver.3 also has Linux edition specifically useful for numerous simulations.