传统的植株营养诊断多采用养分临界值的方法。即通过大量试验确定某一植物在某一生长时期某一养分的临界浓度,若实测值大于该临界值,就不必施肥;若实测值低于该临界值则应施肥。该法一个十分突出的缺点是受取样部位、时期、品种等因子影响。另外,该法还忽视了养分之间的相互作用,在实际应用中受到限制。 Traditional diagnosis of plant nutrition to use more critical value of the method. That is, through a large number of experiments to determine the critical concentration of a certain nutrient in a certain growth period, if the measured value is greater than the critical value, no fertilization is needed; if the measured value is lower than the critical value, fertilization should be performed. A very prominent shortcoming of this method is that it is influenced by factors such as sampling site, period and variety. In addition, the law also ignores the interaction between nutrients, limited in the practical application.