大白菜氮磷钾吸收动态模型及其吸收特性研究

N,P and K Absorption Characteristics of Chinese Cabbage and Its Simulation Model

通过大田试验定量研究大白菜一个种植周期的氮磷钾吸收特性．改进的氮磷钾吸收动态模型具有最佳的拟合效果，由该模型定量分析可得到最大养分吸收速率、最大养分吸收量及其出现的时间等大白菜氮磷钾吸收特征参数。结果表明。平衡施肥明显提高大白菜氮磷钾的最大吸收速率和最大吸收量；大白菜氮磷钾吸收过程基本同步，吸收特性主要是由品种的营养特性决定；氮磷钾最大吸收速率出现在播种后7l一83d，最大吸收量出现在播种后90～109d。

Field experiment was conducted for quantitative studies of N, P and K absorption characteristics during the whole growth period of Chinese cabbage. The improved dynamic model of NPK uptake had the best fitting effect. According to quantitive analysis from simulation model, the nutrient uptake characteristic parameters including the maximum nutrient uptake velocity and the maximum nutrient uptake and their present time were gained. The results showed that the maximum nutrient uptake velocity and the maximum nutrient uptake of Chinese eabbage were improved by balanced fertilization. NPK uptake process in Chinese cabbage was almost synchronous, absorption characteristics depended mainly on nutrition characteristic of the varieties. NPK uptake velocity in Chinese cabbage reached their maximum value at 71 th-83 th day after the transplanting. But the maximum uptake eapaeity for NPK reached their maximum value at 90 th-109 th day after the transplanting.