氮肥运筹方式对孕穗期受渍冬小麦穗部结实特性与产量的影响

以小麦品种皖麦54为试验材料，连续两个生长季进行了氮肥运筹方式对孕穗期渍水冬小麦不同小穗位、粒位的结实粒数和粒重影响的观测。结果表明，不同氮肥运筹方式显著影响穗部结实特性，主茎穗结实特性优于分蘖穗。全部基施的氮肥运筹方式较基肥50%+拔节肥50%和基肥30%+拔节肥50%+孕穗肥20%的运筹方式显著增加了不孕小穗数，降低结实小穗数和结实粒数，2008—2010两年度全部基肥运筹方式较基肥30%+拔节肥50%+孕穗肥20%氮肥运筹方式处理不孕小穗数分别增加25.5%和29.8%，结实小穗数均降低5.7%。孕穗期渍水逆境对分蘖穗结实特性影响大于主茎穗，渍水逆境显著增加不孕小穗数，较对照处理，2008—2010两年度，不孕小穗数分别增加10.6%和4.6%；结实小穗数分别降低2.8%和1.4%。孕穗期渍水降低主茎穗结实4粒的小穗数比例和分蘖穗结实3、4粒小穗数的比例及第3、第4粒位籽粒粒重和第3、第4粒位粒重对单穗粒重的贡献率。氮肥后移运筹方式显著提高孕穗期受渍小麦主茎、分蘖穗结实小穗数和粒重，增加主茎和分蘖穗结实3、4粒小穗的比例和结实小穗第3、4粒位的粒重，提高第3、4粒位粒重对单穗粒重的贡献率，减少不孕小穗数，进而较氮肥前移处理显著提高经济产量。氮肥后移运筹方式有利于减轻孕穗期渍害对小麦穗部结实特性的影响。

Effects of Nitrogen Fertilization on Seed-setting Characteristics of Spike and Grain Yield in Winter Wheat under Waterlogging at Booting Stage

Waterlogging has great influence on yield reduction in winter wheat production in some areas of China. Nitrogen (N) application is believed to be able to improve dry matter translocation in wheat, as a result to increase final yield. In a field experiment across two growing seasons, we used winter wheat cultivar Wanmai 54 to investigate the effect of waterlogging at booting stage and N fertilizing strategy on number and weight of grain at different spikelet positions and grain positions. Under both waterlog...