Evaluation and application of the ORYZA rice model under different crop managements with high-yielding rice cultivars in central China

ORYZA version 3, as the successor to ORYZA2000, is an ecophysiological model that can simulate rice growth and development for targeted yield with different nitrogen (N) fertilizer rates and planting densities in a given rice production system. Currently, there is little published information on the application of ORYZA (v3) and ORYZA2000 in simulating high-yielding rice cultivars under different N rates and planting density schemes in central China. This paper combines field experimentation with ORYZA (v3) to calibrate the crop growth characteristics of widely grown high-yielding inbred and hybrid rice cultivars. The calibrated model was applied to simulate yields under different N rates, planting densities, and seedlings per hill, using historical weather data from 1986 to 2015. ORYZA (v3) reliably simulated the dynamics of crop biomass and leaf area index, and seasonal yield, with relatively small normalized root mean square error (RMSEn) and high adjusted linear correlation coefficient (R2), but slightly over-estimated leaf N concentration. Scenario analyses indicated that the maximum differences in simulated yields were 72.1 kg ha−1 due to planting density, 112.8 kg ha−1 due to seedlings per hill, and 3266.2 kg ha−1 due to N rates. The simulations demonstrated that further field experiments are crucial in investigating the effects of rice genotype, N management and their interactions on yield for optimal crop management.