水氮互作对冬小麦氮素吸收分配及土壤硝态氮积累的影响

Effects of Nitrogen and Irrigation Interaction on Nitrogen Uptake and Distribution in Winter Wheat and Nitrate Accumulation in Soil

试验采用完全随机裂区设计,研究不同灌水和施氮处理对田间冬小麦氮素吸收转运分配以及成熟期土壤剖面硝态氮分布积累的影响。结果表明:冬小麦氮素吸收速率在拔节-开花期达到最大;阶段氮素吸收量、籽粒氮素积累量和氮收获指数均随灌水量的增加而增加,表现为W1500>W1200>W900>W0;施氮量超过150kg/hm2时,籽粒氮素积累量、氮收获指数,拔节-成熟期的氮素吸收量不再显著增加;灌水和施氮均能增加冬小麦营养器官氮素转移量,氮素转运率随施氮量增加而增加,氮素转运贡献率随灌水量的增加而降低;冬小麦成熟期表层(0-20cm)土壤硝态氮含量随着灌水量增加而降低,表现为W0>W900>W1200>W1500;相同灌水处理下,各土层硝态氮含量随施氮量的增加而增加,施氮处理能显著增加0-120cm土层硝态氮含量,当施氮量超过150kg/hm2时,随灌水量增加,土壤剖面中的硝态氮由上层向下层移动。

This field experiment was performed using split-plot design to investigate the effects of different nitrogen and irrigation interaction on nitrogen uptake and distribution in winter wheat and nitrogen accumulation in soil.In this study,four irrigation levels（0 m3/hm2（W0）,900 m3/hm2（W900）,1 200 m3/hm2（W1200）,1 500 m3/hm2（W1500）） in main plots and five nitrogen levels（0 kg/hm2（N0）,90 kg/hm2（N90）,150 kg/hm2（N150）,210 kg/hm2（N210）,270 kg/hm2（N270）） in sub-plots were used.The results showed that the maximum rate of N uptake in the growth stage occurred from jointing to flowering.Nitrogen uptake at winter wheat growth stage,grain nitrogen accumulation and nitrogen harvest index were increased with increasing irrigation amount（W1500 W1200 W900 W0）.Grain nitrogen accumulation,nitrogen harvest index and amount of nitrogen accumulation from jointing stage to mature stage did not significantly increase when nitrogen rate exceed 150 kg/hm2.Irrigation and nitrogen application could increase wheat nutritional organs nitrogen translocation amount.Nitrogen translocation efficiency was increased with increasing nitrogen application rate,and nitrogen translocation contribution proportion was decreased with increasing irrigation amount.Nitrate content in surface soil（0-20 cm） was decreased with increasing irrigation amount at the mature period of winter wheat（W0 W900 W1200 W1500）.Nitrogen application was significantly increased the soil nitrate nitrogen content in the 0-120 cm soil layer in the same irrigation treatment.While the nitrogen exceeded 150 kg/hm2,nitrate nitrogen in soil profile moved from upper to lower layers with increasing irrigation amount.