Abstract:Use the SPAD-502 chlorophyll meter to rapid,on-farm analysis crop chlorophyll status and nitrogen fertilizer recommendation.The result showed that the middle of the last opened wheat leaves was a suitable position for testing of winter wheat N nutrition by chlorophyll meter,which gave a significant relationship with total N in wheat,rate of N fertilizer and crop grain yields.Because the varieties influenced greatly on the values of chlorophyll meter,so the meter was therefore promising for the detection of winter wheat N deficiency by comparison of production fields to well-fertilized plots or strips.