作物氮素吸收与分配的动态模拟

Simulation on nitrogen uptake and partitioning in crops

对作物氮素的吸收和分配的模拟作了一些改进:假定作物地上部与根系的生长总是处于基本平衡状态,作物根系本身不成为限制养分吸收的因素,从而避免了对根系生长和功能变化模拟的困难;采用高产条件下的作物氮素相对吸收速率反映作物对土壤养分要求随生育期的变化;用氮素分配指数描述氮素的分配。采用江苏响水、扬州两地的试验资料对模型检验,表明模型对小麦植株含氮率动态有较好的预测效果。图5,参15。

This paper deals with the improvement in the simulation models of nitrogen uptake and partitioning in crops. To get rid of the difficulty in crop root growth simulation, an assumption was made that the crop roots could not be a limiting factor as the result of coordinative growth of shoot and roots The relative nitrogen uptake rates varying with physiological development time (PDT) under high-yielding conditions were used to calculate the critical nitrogen concentrations in soils. Nitrogen partitioning indexes in crop organs were defined for the dynamic simulation of nitrogen partitioning in cereal crops. The models were tested with field experiment data for nitrogen concentrations in wheat plant, with a good performance.