Dr.ir. H.F.M. ten Berge
Research Institute for Agrobiology and Soil Fertility (AB-DLO)
Dept. Agrosystems Research
6700 AA Wageningen
ORYZA1 is an ecophysiological model for irrigated rice production. The main structure and basic routines are from the Wageningen models for potential production (INTERCOM - Kropff & van Laar, 1993; SUCROS - Spitters et al., 1989; van Laar et al., 1992; MACROS module L1D - Penning de Vries et al., 1989). An important advantage of the current model is that it can be used to simulate realistic yields and to assess the impact of planting date, weather, latitude at measured leaf N contents. This is in contrast to models for potential production, that have a fixed pattern of leaf photosynthesis in time. The model follows the daily calculation scheme for the rates of dry matter production of the plant organs, and the rate of phenological development. By integrating these rates over time, dry matter production of the crop is simulated throughout the growing season. The model ORYZA1 can be used as a tool in rice research for different types of studies: 1. Detailed physiological analysis of field experiments. It enables interpretation of treatment differences in yield in terms of LAI development, leaf N content, weather conditions and varietal characteristics determining physiological and morphological processes. For this purpose, detailed measurements are required on LAI and leaf N content, preferably throughout the growing season, although a single measurement at flowering can be seen as a minimum data set. 2. Extrapolation of experimental findings to other environments. Given the N content oie leaves throughout the growing season and the varietal characteristics, attainable yields can be estimated for other environments (planting date, irradiation, temperature). 3. Estimation of yield potential for a given environment (planting date, latitude, radiation, temperature, variety as input) based on the leaf N content of the highest yielding experiments. The leaf N contents measured in the recent IRRI experiments used for model development can be used as a starting point. 4. Estimation of the effect of climate change on yield potential.
Author of the abstract:
CAMASE Register of Agro-ecosystems Models
Kropff, H.H. van Laar & R.B. Matthews (Eds.), 1994.
ORYZA1 rice production.
SARP Research Proceedings, IRRI, TPE-WAU, AB-DLO. 110 pp.