我国北方地区几种主要作物氮营养诊断及追肥推荐研究　Ⅲ.春小麦氮营养诊断及追肥推荐体系的研究

NITROGEN NUTRITIONAL DIAGNOSIS AND RECOMMENDATION AS TOPDRESSING FERTXLIZER N FOR SEVERAL CROPS IN NORTH CHINA Ⅲ. Nitrogen nutritional diagnosis and recommendation as topdressing fertilizer N for spring wheat

通过田间试验研究了两种快速诊断方法，二苯胺法和反射仪法在春小麦氮营养诊断中的应用。提出春小麦最佳氮营养诊断时期和诊断部位为拔节前茎基部节间组织。确定了春小麦用两种方法进行氮素诊断的临界值分别为2.55（NO3-N色阶，二苯胺法）和2600mgkg-1（NO3-，反射仪法）。同时建立了氮营养诊断的追肥推荐模型。

Two quick test methods (diphenylamine method and nitrate test strip) for diagnosising nitrogen nutritional status under condition of rotatiori cropping with winter wheat-summer corn were studied in field expriment. The results suggested that the optimum diagnosis parts of plants was the stem base for wheat arid the midrib of near matured leaf for corn, both just prior to jointing stage, arid the critical values of nitrate was considered to be 2.00(diphenylamine method) and 1500mgkg-1No3- (nitrate test stripe) for wheat and 2. 40(diphenylamine method) and 1240mgkg-1NO3-(nitrate test stripe) for corn. Based upon the results from nitrogen nutritional diagnosis, series fertilizer N topdressing recommendation model was set up as following:wheat:Nd=220. 2-95. 8Td(diphenylamirie method) Nd=220. 2-0. 147Tr(nitrate test strip) corn:Nd=185. 9-72. 5Td(Yuncheng, diphenylamine method) Nd=185. 9-0. 13Tr(Yuncheng, nitrate test strip) Nd=176. 2-80. 5Td(Yongji, diphenylamine method)