【目的】本试验采用自行设计的新型负压水肥一体化灌溉系统,进行了系统供水负压对土壤硝态氮分布和黄瓜水氮利用效率影响的研究,以期为实际应用和管理提供理论依据和技术参考。【方法】在遮雨网室内进行了供水和施氮双因素盆栽试验。以常规灌溉为对照(CK),设4个供水水平:0(W1)、–5(W2)、–10(W3)和–15 k Pa(W4),2个施氮水平(N1,N 0.3 g/kg土;N0,不施氮),共10个处理。分析检测了黄瓜生育期内0—25土壤水分变化动态、土壤硝态氮的空间分布特征,计算了黄瓜的水、氮利用效率。【结果】随着黄瓜耗水量的增加,系统供水量也增大,系统累计供水量与黄瓜累计耗水量之间存在极显著线性关系y=0.96x+3.4(R2=0.99,P<0.01)。不同供水负压对同一时期土壤含水量变化有极显著影响(P<0.01),当供水负压设定在0、–5、–10和–15 k Pa时,土壤平均质量含水量分别为28.7%、22.7%、20.0%和15.6%,而在同一系统供水负压下黄瓜整个生育期土壤含水量保持相对稳定,其变化属于弱变异(变异系数CV≤0.1)。负压灌溉水肥一体化能显著提高0—25 cm土壤氮素分布的均匀性,土壤硝态氮沿垂直方向的平均变差系数分别比常规灌溉降低了58.6%~71.2%。同一系统供水负压下,施氮处理(N1)黄瓜植株干物质量、产量和水分利用效率比不施氮处理(N0)分别提高了4.6%~256.1%、12.6%~196.6%和7.76%~86.27%。当供水负压为–5 k Pa时,黄瓜植株平均干重和产量均为最高,分别为153 g/pot和1406 g/pot,黄瓜平均水分利用效率和氮肥表观利用率分别比常规灌溉提高了136.8%和52.32%。【结论】适宜的供水负压下,负压灌溉系统通过土壤水分平衡供应机制,实现了作物对水分的连续自动获取,黄瓜整个生长期间,灌溉系统可以保持平稳均匀与适时适量供水,因而,负压灌溉水肥一体化显著提高了黄瓜的水、氮利用效率。本试验条件下,系统供水负压为–5 k Pa更有利于黄瓜的产量和氮素利用率的提高。 【Objective】 In this experiment, a new type of integrated negative pressure water and fertilizer irrigation system designed by ourselves was used to study the effect of negative pressure of system water supply on soil nitrate nitrogen distribution and cucumber water and nitrogen use efficiency, in order to provide theoretical basis for practical application and management and Technical reference. 【Method】 The two-factor pot experiment with water supply and nitrogen application was conducted in the shelter. Based on the conventional irrigation control (CK), four water supply levels were set at 0 (W1), -5 (W2), -10 (W3) and -15 kPa g / kg soil; N0, no nitrogen), a total of 10 treatment. The dynamic changes of 0-25 soil water content and the spatial distribution of soil nitrate nitrogen during the growth and development of cucumber were analyzed. The water and nitrogen use efficiency of cucumber was calculated. 【Result】 With the increase of cucumber water consumption, the system water supply also increased. There was a very significant linear relationship between the cumulative water supply of cucumber and water consumption of cucumber y = 0.96x + 3.4 (R2 = 0.99, P <0.01). The negative pressure of different water supply had a very significant effect on the change of soil water content in the same period (P <0.01). When the negative pressure of water supply was set at 0, -5, -10 and -15 kPa, the average soil water content was 28.7 %, 22.7%, 20.0% and 15.6%, respectively. However, the soil water content of cucumber remained relatively stable throughout the growth period under the negative pressure of water supply in the same system, and its variation was weak variation (coefficient of variation CV≤0.1). The integration of water and fertilizer under negative pressure irrigation can significantly improve the uniformity of nitrogen distribution in 0-25 cm soil, and the average coefficient of variation along the vertical direction of nitrate nitrogen in soil decreased by 58.6% -71.2% compared with conventional irrigation. Under the same system water supply pressure, the dry matter yield, water use efficiency and NUE of cucumber increased by 4.6% ~ 256.1%, 12.6% ~ 196.6% and 7.76% ~ 86.27 %. When the negative pressure of water supply was -5 kPa, the average dry weight and yield of cucumber plants were the highest, which were 153 g / pot and 1406 g / pot respectively. The average water use efficiency and apparent nitrogen use efficiency of cucumber were higher than conventional irrigation 136.8% and 52.32% respectively. 【Conclusion】 Under suitable water supply pressure, the negative pressure irrigation system can achieve continuous automatic crop water harvesting through the mechanism of soil water balance supply. During the whole growing period of cucumber, the irrigation system can maintain a steady and even water supply. Therefore, negative pressure Pressure irrigation water and fertilizer integration significantly increased cucumber water and nitrogen use efficiency. Under the experimental conditions, the negative pressure of water supply in the system is -5 kPa, which is more conducive to the increase of cucumber yield and nitrogen utilization rate.