中文摘要：

水分、盐分和施氮量是影响作物生长的主要因素,基于在内蒙古河套灌区开展的盆栽实验,对水、盐、氮交互作用下向日葵对水分的吸收和利用进行了初步探讨。具体而言,土壤水分、盐分和施氮量各设置两个水平,分别为：轻度盐分胁迫（S0：0.2%~0.45%）和中度盐分胁迫（S1：0.45%~0.7%）;水分胁迫处理（W0：田间持水量的35%~55%）和充分灌溉处理（W1：田间持水量的75%~100%）;全生育期不施用氮肥的氮素胁迫处理（N0）和播种前按135kg/hm2（以纯N计）的施氮的无胁迫处理（N1）。实验结果表明：中度盐分胁迫（S1）在蕾期对根系储水量有明显的抑制作用,并降低了向日葵蕾期和花期的水分利用率,此外,S1处理还降低了向日葵花期和成熟期的腾发量;水分胁迫（W0）处理降低了向日葵根系储水量,在开花时充分灌溉会显著提高向日葵的腾发量和水分利用率;与土壤盐分和水分相比,施氮量对向日葵水分利用的影响较小,但氮素胁迫（N0）在实验中对根系吸水量、腾发量和水分利用率也有一定的抑制作用。

英文摘要：

The coupling effects of water,nitrogen and salinity on crops are complicated.Based on pot experiments,this paper mainly discusses the water use of sunflowers（LD5009）under the influence of water,salinity and nitrogen.And we focus on Root Water Uptake（RWU）,Evapotranspiration（ET）,and Water Use Efficiency（WUE）,which are closely linked to the water use of crop.There are two treatments of salinities levels,i e.light salt stress（0.2%~0.45%）,moderate salt stress（0.45%~0.7%）,two irrigation amount levels,i.e.deficit irrigation（35%~55%）,full irrigation（75%~100%）and without applying nitrogen during growth period and apply with 135kg/hm2 before planting.The experimental results indicate that moderate salt stress decreases RWU observably in bud,reduced WUEin bud and flowering,and decreases ETin flowering and mature.On the other hand,deficit irrigation brought down RWU.However,full irrigation has significantly improved ETand WUE.In contrast to water and salinity,although the effect of nitrogen was weaker than water and salinity,nitrogen stress has also slightly decreased RWU,ETand WUE.