水稻氮素分配指数的试验研究与动态模拟

提出养分分配指数即某一时刻地上部各器官的吸氮量与地上部总吸氮量的比例的概念来描述水稻氮素的分配．在扬州大学实验农场进行了不同品种与不同氮肥用量对水稻氮素分配影响的试验，结果表明，水稻氮素分配指数表现出一致的规律性变化．根据分配指数的变化特点，构建了叶片、茎鞘、穗部氮素分配指数随水稻生理发育时间变化的动态关系模型，从而较简明地反映水稻植株各器官氮分配指数的连续变化，提高了模拟的可用性．将品种特征参数和施氮水平作为调节因子引入模型，提高了模型的适应能力．对叶片和穗氮素分配指数模拟的相对误差分别为7．2％和6．3％，模拟效果良好．

Experimental Researches and Dynamic Modeling on the Partitioning Index of Nitrogen in Rice

The concept of nitrogen partitioning index were put forward to describe the nitrogen partitioning in rice.The nitrogen-partitioning index was defined as the proportions of respective nitrogen amounts in various organs to the total nitrogen amount in the aboveground plants.The field experiments with four rice cultivars at four nitrogen rates was carried out in the Experimental Farm of Yangzhou University in 2002 and 2003 to study the dynamics of nitrogen partitioning indexes.Based on the experimental results,the simulation models of nitrogen partitioning were developed.The genetic parameter and nitrogen nutrient effects were joined in the models and as a result the adaptability of the models were improved.Test of the simulation model indicated good agreements between the simulated values and the observed values well,with average relative errors(ARE) for the nitrogen-partitioning index to leaves and stem plus sheath being 7.2% and 6.3% respectively.