Modeling Rice Response for Agro-technology Transfer.

Crop growth simulation models are used to predict the performance of a particular rice cultivar sown at any time on any soil in any agro-climatic region.  The model once calibrated for a particular set of soil, weather and crop management conditions can help in accomplishing technology transfer across soil and climate boundaries. Field experiments were conducted in Tamil Nadu Agricultural University, India using rice as test crop. Objectives of the study were to evaluate the response of major rice cultivars, viz., CO 47 and ADT 45, to nitrogen fertilization, to optimize the nitrogen requirement of these cultivars and to employ and calibrate DSSAT (Decision Support System for Agro technology Transfer) rice simulation model and to explore the possibility of using it as a tool for technology transfer across soil and climate boundary. Field experiments were conducted with these two rice genotypes and four N levels viz., 0, 120, 150 and 180 kg N ha^-1.  The calibrated CERES - rice model for CO 47 and ADT 45 rice cultivars were employed to generate scenarios on potential production of these cultivars in different soil and climate situations in five different rice growing tracts within Tamil Nadu. The results revealed that in all the soil and climate situations CO 47 rice cultivar recorded higher potential yield compared to ADT 45 rice cultivar. The results of the present study indicated that the calibrated models can help to fine tune the nitrogen fertilizer application in rice ecosystems of the state.