氮肥施用期对春小麦氮素利用和蛋白质产量的效应

春小麦生育期间植株各器官土壤氮与肥料氮变化趋势基本一致。各器官吸收总氮量中,土壤氮约为肥料氮的2～3倍,肥料氮对土壤有激发效应。肥料利用率随氮肥施用期的后移和施用量的增加而逐渐提高。氮肥不同施用期对提高籽粒蛋白质含量有极显著效应(F=31.3>F_(0.01)=4.22),籽粒蛋白质含量随氮肥施用期推迟而显著增加;对籽粒蛋白质产量的效应则差异不显著。生育前期施氮有利于籽粒产量形成,开花期叶面喷施氮肥显著提高籽粒蛋白质含量。

EFFECTS OF NITROGEN APPLICATION TIME ON NITROGEN UTILIZATION ANDNPROTEIN YIELD IN SPRING WHEAT

The studies were carried out in 1988～1989 on the campus of NEAC.The pot exper-iment consisted of seven fertilization treatments (T1:control;T2:fertilizer at seeding;T3:fertilizer at 3-leaf stage;T4:fertilizer at anthesis;T5:3/4 T2+1/4 T3;T6:3/4T2+1/4T4;T7:1/2T2+1/4T3+1/4T4)。The objectives of the experiment were(a) the effect of nitrogen application time on the utilization of ~(15)N-labeled urea.(b) themeasure of fertilization for increasing protein yield perunit area in spring wheat inHeilongjiang province.During the process of plant growth and development,the change of soil nitrogen had asimilar trend to that of fertilizer nitrogen in different organs of spring wheat plants,of totalnitrogen accumulation,three fourths were derived from the soil,and the rest fromfertilizer.Moreover,at maturity,the efficiency of fertilizer utilization was raised by delayingand increasing fertilizer application.The effects of nitrogen application time on the increase of grain protein content were sig-nificant (F=31.3>F=4.22) but not on grain protein yied.Grain protein content was in-creased by delaying nitrogen appilcation.In different treatments,early appiocation of nitro-gen fertilizer was efficient for the formation of grain yield,and grain protein contern wassignificantly increased by foliar-spraying of nitrogen fertiliaer at anthesis。