为明确不同形态氮肥及配比对西瓜生产性能的影响，为西瓜栽培中氮肥选择提供依据。以陇抗9号为供材，在等氮水平(N 200 kg/hm2)下，设3种形态氮肥(酰胺态氮、硝态氮、铵态氮)和3种硝铵配比(70%硝态氮+30%铵态氮、50%硝态氮+50%铵态氮、30%硝态氮+70%铵态氮)处理，研究了不同施肥处理对西瓜干物质积累、产量、品质及氮素养分积累利用指标的影响。结果表明，单一氮肥种类对西瓜植株干物质积累、产量、氮素养分积累及利用的影响为硝态氮＞酰胺态氮＞铵态氮；70%硝态氮+30%铵态氮能够维持较好的果实品质，其西瓜产量、经济收益、氮肥利用率和偏生产力最高，与酰胺态氮相比，西瓜产量提高了15.24%、经济收入增加了 6 056元/hm2、氮肥利用率提高了7.95个百分点、氮肥偏生产力增加了15.24%。综上所述，西瓜生产在施氮200 kg/hm2水平下以70%硝态氮+30%铵态氮的比例投入为佳，适宜在实际生产中应用。

In order to explore the effect of different forms of nitrogen fertilizer and their ratios on the production performance of watermelon, so as to provide a basis for nitrogen fertilizer selection in watermelon cultivation, Longkang 9 was selected as the experimental material. The effects of different fertilization treatments on dry matter accumulation, yield, quality and nitrogen accumulation and utilization indexes of watermelon were studied by using three nitrogen fertilizer treatments(amide nitrogen, nitrate nitrogen and ammonium nitrogen) and three ammonium nitrate ratios(70% nitrate nitrogen+30% ammonium nitrogen, 50% nitrate nitrogen+50% ammonium nitrogen, 30% nitrate nitrogen+70% ammonium nitrogen) with same amount of nitrogen application rate applied(N 200 kg/ha). The results showed that the effects of single nitrogen fertilizer on dry matter accumulation, yield, nitrogen accumulation and utilization of watermelon plants were nitrate nitrogen > amide nitrogen > ammonium nitrogen. 70% nitrate nitrogen+30% ammonium nitrogen could maintain better fruit quality, and watermelon yield, economic benefit, nitrogen utilization rate and partial productivity were the highest. Compared with amide nitrogen, watermelon yield increased by 15.24%, economic income increased by 6 056 Yuan/ha, nitrogen utilization rate increased by 7.95%, and nitrogen partial productivity increased by 15.24%. Therefore, it is better to use 70% nitrate nitrogen+30% ammonium nitrogen in watermelon production at the nitrogen application level of 200 kg/ha, which is suitable for practical application.

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甘肃省农业科学院博士基金项目(2022GAAS61)；国家西甜瓜产业技术体系-土壤与养分管理岗位(CARS-25)。