不同冬小麦品种氮素营养诊断指标研究

Study on Nutrition Diagnosis Index of Different Winter Wheat Cultivars

为建立冬小麦氮素营养诊断指标,以豫麦49和豫农949为供试材料,在河南两个试点,设置施氮水平分别为0、90、180、270和360kg·hm^-2,研究了不同氮肥用量对冬小麦产量和茎基部硝酸盐浓度的影响。结果表明,两个冬小麦品种的产量均随施氮量的增加先增加后下降,豫麦49在施氮量为180kg·hm^-2时最高,而豫农949在270kg·hm^-2时最高;不同试点的两个冬小麦品种的产量差异显著,但最高产量的施肥水平表现一致。两个小麦品种在返青期、拔节期和孕穗期茎基部硝酸盐浓度与施氮量均极显著相关,两个试点两个小麦品种在返青期茎基部硝酸盐浓度与产量均显著相关。返青期可作为小麦硝态氮氮素营养的诊断期,豫麦49诊断临界范围为1 847-1 978mg·kg^-1,豫农949为1 488-1 592mg·kg^-1。

To establish the winter wheat nitrogen status diagnostic index,the effects of different amounts of nitrogen fertilizer on winter wheat yield and concentrations of nitrate-nitrogen in stem base were studied using reflectometer,with wheat cultivars Yumai 49 and Yunong 949 as materials at two experimental sites in Henan.Five fertilization rates（N 0,90,180,270,360kg· hm^-2）were set up.The results showed that the yield of two cultivars firstly increased,then decreased with increase of the nitrogen rate.The yield of Yumai 49 and Yunong 949 respectively reached the maximum when the amount of fertilizer was 180kg·hm^-2 and 270kg·hm^-2.There was a significant linear correlation between stem nitrate nitrogen content and nitrogen fertilizer at regreening,jointing and booting stages.The stem nitrate nitrogen content at regreening stage was significantly correlated with wheat yield.The results suggested that the regreening stage could be tested as the diagnosis time of nitrate-N nutrition and the critical range was suggested to be 1 847-1 978mg·kg^-1 for Yumai 49 and 1 488-1 592mg·kg^-1 for Yunong 949,respectively.