水氮供应对棉花花铃期净光合速率及产量的调控效应

为揭示水氮供应对黑河中游边缘绿洲沙地农田棉花光合特性和产量的调控效应，采用3种灌溉水平和5种氮素水平的田间试验，研究水氮供应对花铃期棉花净光合速率及产量的影响。结果表明，在施N 0～300 kg/hm2范围内，棉花花铃期日均净光合速率和蒸腾速率均随施氮量增加而增加，超过N 300 kg/hm2时略有下降。施N 150、225、300和375 kg/hm2较不施氮处理籽棉产量分别增加33.9%、45.8%、50.9%和49.2%；灌溉水生产力分别提高33.3%、45.8%、50%和50%。3个灌溉处理间籽棉产量差异不显著，灌溉水生产力依I1（10800 m3/hm2）、I2（9450 m3/hm2）、I3（8100 m3/hm2）顺序递增。棉花花铃期净光合速率与籽棉产量、秸秆生物量、单株铃数、铃重和籽指间均存在极显著正相关关系。在黑河中游边缘绿洲沙地农田，施N 300 kg/hm2能够促进棉花花铃期净光合速率，有利于籽棉产量和水生产力的提高；与当地采用的10800 m3/hm2灌溉量相比，降低灌溉量至8100 m3/hm2不降低籽棉产量，使灌溉水的生产力提高27.5%。

Responses of net photosynthetic rate in flowering and boll-forming stages, and cotton yield to irrigation and nitrogen fertilizer application

The regulating effects of irrigation and nitrogen fertilizer application on net photosynthetic rate in flowering and boll-forming stages and cotton yield were studied on a sandy farmland in the marginal oasis in the middle of Heihe River basin.Two factors including 3 irrigation levels and 5 nitrogen fertilizer levels were set up.The results showed that both average daily net photosynthetic and transpiration rates of cotton leaves in flowering and boll-forming stages increased with nitrogen fertilizer applic...