中文摘要：

通过田间试验研究了不同氮肥运筹方式对砂田西瓜产量、品质及氮素和干物质积累与转运的影响.结果表明：基肥氮过低或过高均不利于砂田西瓜苗期生长,伸蔓期或膨果期不施氮肥则限制了西瓜＂源＂或＂库＂的形成,在相同的施氮量水平下,T4（30%基肥＋30%伸蔓肥＋40%膨瓜肥）和T6[100%基肥＋长效复合肥添加剂（NAM）]处理较传统施肥模式T1（30%基肥＋70%伸蔓肥）西瓜坐果后茎叶干物质和氮素积累量显著降低,而果实干物质和氮素积累量显著增加.其中,T4处理的氮素运转率和氮素贡献率分别达到33.6%和12.0%,T4和T6处理的氮素收获指数、氮肥偏生产力和氮肥利用率较传统施肥模式T1分别显著提高14.1%和12.7%、11.6%和12.5%、5.3%和8.7%.T4和T6处理较T1西瓜分别增产11.6%和12.5%,可溶性糖含量分别显著提高16.5%和11.7%,有效酸度分别提高4.5%和2.8%,糖酸比分别提高19.4%和13.4%,Vc含量分别提高35.6%和19.0%.因此,T4和T6处理为砂田西瓜高产优质的较优氮肥运筹模式,若减轻砂田施肥难度,延长砂田使用年限,可采用100%基肥＋NAM（T6）的施肥方式.

英文摘要：

The effects of nitrogen management on yield,quality,nitrogen and dry matter accumulation and transportation of watermelon in sand field were studied based on a field experiment. The results showed that too low or too high basal nitrogen fertili-zation was unfavorable to seedling growth of watermelon in sand field,and no nitrogen application at vine extension or fruiting stages limited the formation of ‘source＇or ‘sink＇. At the same nitrogen rate,compared with the traditional T1 treatment（ 30% basal N fertilizer ＋ 70% N fertilizer in vine extension）,the nitrogen and dry matter accumulation of vegetative organs of T4treatment（ 30% basal N fertilizer ＋ 30% N fertilizer in vine extension ＋ 40% N fertilizer in fruiting） and T6treatment（ 100% basal N fertilizer ＋ NAM） were reduced significantly,but the nitrogen and dry matter accumulation of fruit were increased significantly in the flushing period. The nitrogen transportation ratio and nitrogen contribution ratio of T4 were 33.6% and 12.0%,respectively. Compared to T1,the nitrogen harvest index,nitrogen fertilizer partial factor productivity and nitrogen fertilizer recovery efficiency of T4 and T6treatments increased by 14.1% and 12.7%,11.6% and 12.5%,5.3% and 8.7%,respectively,and yield of watermelon increased by 11.6% and 12.5%,the soluble sugar,effective acid,the ratio of sugar and acid,Vc content increased by 16.5% and 11.7%,4.5% and 2.8%,19.4% and 13.4%,35.6% and19.0%,respectively. Therefore,T4 and T6treatments were the optimal nitrogen fertilizer management mode which could not only achieve high yield and quality but also obtain high nitrogen fertilizer use efficiency in sand field. T6 treatment was the best nitrogen fertilizer management mode considering reduction of fertilizing labor intensity and extending service time of gravel-mulched field.