膜下滴灌水氮耦合对干物质积累和氮素吸收及水氮利用效率的影响.doc

膜下滴灌水氮耦合对干物质积累和氮素吸收及 水氮利用效率的影响 谢志良,2，田长彦 1* 1.中国科学院新疆生态与地理研究所,乌鲁木齐 830011; 2.中国科学院研究生院,北京 100049 摘要:通过大田试验，研究了膜下滴灌水氮耦合对花铃期至吐絮期根冠生物量，养分吸收及产量、水氮利用效率的影响。结果表明：水氮供应促进花铃期根冠生长。随生育期的推延，水分胁迫作用加强，氮素的促进效应受到明显的抑制。吐絮期水分胁迫下施氮对地上部的影响不大，根干重以N276最高。水分充分增加氮素供应，根干重减少，地上部生物量和养分吸收增加但以N276最高。花铃期至吐絮期间，水氮促进根冠生物量，养分积累量增加。无论灌水如何，高氮抑制了根冠干重在这段生育期积累。产量、水氮利用效率的最高点不一致。灌水量增加，产量和氮素利用效率增加，水分利用效率下降。增加氮素的供应，氮素利用率下降，水分利用率增加；水分胁迫时产量差异不大，正常灌水产量增加但以N276最高。水氮耦合以施氮276kg/hm2灌水600mm获得最大的产量，水氮利用效率较高。 关键词:氮素吸收；水氮利用效率；皮棉产量；棉花 Coupling Effects of Water and Nitrogen on Dry Matter Accumulation,Nitrogen Uptake,Water and Nitrogen Use Efficiency under Mulched Drip Irrigation Xie Zhi-liang1,2 Tian Chang-yan1 (1 Xinjiang Institute of Ecology and Geography, Chinese Academy of Science, Urumqi 830011,Xinjiang, China; 2 Graduate University of Chinese Academy of Science, Beijing 10049,China ) Abstract: Field trials were conducted to study the coupling effects of water and nitrogen on the dynamics of nutrient uptake and dry matter accumulation from flowering and boll setting stage to boll opening stage, lint yield, water and nitrogen use efficiency. Experimental results showed that during flowering and boll-setting stage, water and nitrogen supply promoted root and shoot growth. With growth stage developing, the effect of water stress enhancd,the promotive effect of nitrogen was? issubjected to significant limit. Boll opening stage, nitrogen supply had no effect on above-ground, root dry weight was maximum at 276kg/hm2 nitrogen level under water stress; root dry weight was reduced with nitrogen supply, above-ground dry weight and nutrient uptake were maximum at 276kg/hm2 nitrogen level under sufficient water supply. From flowering and boll setting stage to boll opening stage, water and nitrogen supply promoted root and shoot dry weight accumulation during this growth stage. At two irrigation amount levels, too much nitrogen supply inhibited root and shoot accumulation during this growth stage.?The high