雨养与灌溉条件下施氮对小麦花后氮素累积与转运的影响

为给冀东平原冬小麦雨养和灌溉栽培中合理施氮提供依据,以小麦品种京冬8号和宝麦38为材料,在雨养、灌溉条件下各设置4个施氮水平(0、120、240、360kg·hm-2),研究了两种水分条件下施氮量对小麦植株氮素吸收、累积和转运的影响。结果表明,施氮可显著增加小麦的籽粒产量和蛋白质含量,但过多施氮会导致产量下降。增施氮肥明显提高了小麦花后各器官的氮素累积量及叶、茎、鞘的花前贮存氮素转运量,同时增加了成熟期叶、茎、鞘的氮素残留量。营养器官的氮素累积量及花前贮存氮素的转运量在水分条件间和品种间也存在明显的差异。综合分析,在雨养条件下,京冬8号和宝麦38最适施氮量分别为240和120kg·hm-2,灌溉条件下均为120kg·hm-2。

Effects of Nitrogen Fertilizer Rates on Nitrogen Accumulation and Translocation after Anthesis in Wheat under Rain fed and Irrigated Conditions

In order to provide theoretical basis for nitrogen application under rain fed and irrigated conditions in eastern of Hebei province. A field experiment was conducted to investigate the characters of nitrogen (N) uptake, accumulation and translocation in two winter wheat cultivars: Jingdong 8 and Baomai 38 after anthesis at 4 N levels (0, 120, 240 and 360 kgN·hm^-2) under the rain fed and irrigated conditions. The results showed that the grain yield and the total protein content of the grain were increased significantly with the increasing of N rate, but under the rain fed condition, the yield of Jingdong 8 and Baomai 38 began to decline at 360 and 240 kgN·hm^-2 respectively, and the yield of both Jingdong 8 and Baomai 38 began to decline at 240 kgN·hm^-2 under the irrigation condition. The N fertilization obviously increased N accumulation in aerial parts of wheat after anthesis and the N translocation in leaves, stems, and sheaths of wheat. However, the N accumulation in wheat vegetative organs and the N translocation in leaves, stems and sheaths were different between two wheat cultivars under the same N fertilizer level or different water treatment. And the residual N in leaves, stems, and sheaths at the maturing stage showed an obvious upward trend with the increasing of N rate. The final results showed that, applying 240 kgN·hm^-2 for Jingdong8 and 120 kgN·hm^-2 for Baomai 38 were the best treatments under both rain fed and irrigation conditions.