作物钾素养分的动态模拟

Dynamic simulation on potassium nutrient in crop-soil systems

定义土壤水溶性钾、交换性钾、缓效性钾是土壤中作物可利用的钾,将交换性钾、缓效性钾与外源钾吸附量的总和作为土壤最大吸附量的估计,从而综合反映土壤各种钾素状态和土壤性质对钾有效性的影响。用线性方程描述最大吸附量与土壤黏粒含量的关系,用Langmuir方程描述土壤固定钾量与土壤溶液钾浓度的关系,通过土壤供钾因子反映土壤钾素状况对作物吸钾的影响。建立了小麦植株临界钾浓度与生理发育时间的动态模型。初步检验表明,模型对小麦植株含钾率的动态变化有较好的预测效果。图2,参15。

The dynamic simulation models of potassium nutrient flow in crop-soil systems were developed at a simplified system level. For potassium dynamics in soils, the maximum potassium absorption capacity is defined as the sum of soluble, exchangeable, non-exchangeable potassium and adsorbed potassium to reflect the integrated effects of different forms of potassium on soil potassium availability. The relationships between total available potassium and equilibrium solution potassium concentrations were described by the Langmuir function. Relative potassium uptake rates varying with physiological development time (PDT) were used to adjust the critical potassium concentrations in soils. The functional relationships of top critical potassium concentrations and potassium partitioning indexes to PDT in wheat were established. The models were tested with field experiment data for potassium concentrations in wheat plant, with a good performance.