Rice (Oryza sativa L.) is the most important grain crop in China, its planting area accounting for 30% of all grain crops, and its yield for 40% of the grain yields. More than half of world's population relies on rice as its primary food staple. China and other rice producing countries face problems of feeding an increasing population, global warming and a reduction in rice planting area. Accurate prediction of rice growth and productivity under varying environmental conditions will be helpful in developing appropriate agricultural policies and ensuring adequate food production.
Crop simulation models can dynamically describe the biophysical and physiological processes of growth, development and yield, and provide a quantitative tool for predicting the productivity level of a crop in relation to genotype, environment and management [1], [2] and [3]. Several growth simulation models have been developed for rice, including SIMRIW [4], CERES-Rice [5] and [6] and ORYZA [7] and [8], each performing well. These models use development stage (DS) or a development index to predict phenology, and use partitioning coefficients to estimate organ biomass. Some coefficients have different values at different stages, which complicates their application. Cao et al. [9] and [10] developed a wheat growth model using physiological development time (PDT) as a scaler for phenology and a partitioning index for organ growth, resulting in fewer parameters while providing good predictability and applicability.
The primary objectives of this study were (1) to develop an eco-physiological process-based simulation model of rice growth, development, and yield (RiceGrow) by quantifying and integrating the fundamental relations of developmental and growth processes with environmental factors, genotypic parameters and management practices by using physiological development time and a partitioning index, and (2) to compare results from the RiceGrow model with results from the ORYZA2000 model using the same datasets to determine if RiceGrow, with fewer input parameters, would provide similar or improved results compared with ORYZA2000 [8].