通过田间试验研究土娄土冬小麦和夏玉米氮肥施用量以及反射仪法在两种作物氮营养诊断中的应用。结果表明 ,冬小麦和夏玉米氮肥最适施用量为 2 0 0～ 2 2 6.6kg/hm2 和 1 1 2 .3～ 2 0 5kg/hm2 。反射仪法测得的 NO- 3和流动注射法比较 ,证明反射仪法可作为一种快速常规分析方法。两种作物采用反射仪法进行氮素营养诊断的临界值分别为冬小麦 1 1 0 0～ 1 650 mg/kg,夏玉米 1 2 0 0～ 1 60 0 mg/kg Field experiments were conducted to study the application of nitrogen fertilizers in winter wheat and summer maize and the application of reflectometry in the diagnosis of nitrogen nutrition in two crops. The results showed that the optimum nitrogen application rates for winter wheat and summer maize were 220 ~ 222.6kg / hm2 and 112 ~ 205kg / hm2. Reflectometry measured by the NO-3 and flow injection compared to prove that reflectometry can be used as a fast routine analysis. The critical values ​​for the diagnosis of nitrogen nutrition by reflectometry in two crops were 1 1 0 0 ~ 1 650 mg / kg for winter wheat and 1 200 ~ 1 60 0 mg / kg for summer maize