为探讨固定道小麦栽培方式下适宜的水氮组合,以低水1200(W_1)、中水2400(W_2)、高水3600 m3·hm~(-2)(W_3)为主处理,0(N_0)、低氮90(N_1)、中氮180(N_2)、高氮270kg·hm~(-2)(N_3)为副处理,采用裂区设计,对固定道垄作栽培方式下水氮互作对春小麦根系生长及产量的影响进行了研究.结果表明:水氮互作能显著影响春小麦根干质量密度(RWD),RWD随着小麦生育期的进程表现为先增大后减小的趋势,在灌浆期达最大;RWD对施氮量的响应取决于灌溉量,在W_1下,RWD在N_1处理下最大,在W_2下,RWD随着施氮量的增加在N_2处理下最大,在W_3下,RWD随着施氮量的增加在N_3处理下最大;不同灌溉处理下RWD表现为W_2>W_3>W_1;施氮与灌水显著影响RWD,表现为灌水>氮肥>水氮互作,在W_2N_2处理下最大.根冠比随着灌水量与施氮量的增加逐渐减小,在W_1N_0处理下根冠比最大;85%以上的小麦根系分布于0~40 cm土层,产量与0~40 cm土层RWD呈显著抛物线回归关系,与40~60cm土层RWD呈显著线性正回归关系.W_2灌溉条件可以促进小麦根系向中下层(40~60 cm)分布;灌水施氮能显著影响春小麦籽粒产量与生物产量,生物产量随着施氮量和灌水量的增加而增加,籽粒产量在W_2N_2最大;灌水生产力随灌水量的增加逐渐降低,氮肥农学利用率随施氮量的增加而减小.因此,在固定道垄作栽培方式下,施肥量与灌水量控制在N_2(180kg·hm~(-2))与W_2(2400 m~3·hm~(-2))条件下有利于促进根系生长,进而提高春小麦籽粒产量及水氮利用效率,是河西灌区固定道小麦栽培方式下适宜的水氮组合. In order to explore the suitable combination of water and nitrogen in fixed - field wheat cultivation, the main treatments were low water 1200 (W_1), middle water 2400 (W_2) and high water 3600 m 3 · hm -2 (W_3), 0 (N_0 ), Low nitrogen 90 (N_1), middle nitrogen 180 (N_2), and high nitrogen 270kg · hm -2 (N_3) as the secondary treatment. Using split-plot design, Growth and yield were studied.The results showed that water and nitrogen interactions significantly affected root dry weight density (RWD) of spring wheat, RWD showed the trend of first increasing and then decreasing with the growth of wheat during the growth period, The RWD response to N application was dependent on the amount of irrigation. Under W_1, RWD was the highest under N_1 treatment. Under W_2, RWD was the highest under N_2 treatment with increasing N application rate. Under W_3, RWD The increase of N application rate was the largest under the treatment of N_3. The RWD performance was W_2> W_3> W_1 under different irrigation treatments. The effects of N application and irrigation on RWD were significant as follows: irrigation> N application> water and nitrogen interaction. The ratio of root to shoot decreased with the increase of irrigation amount and nitrogen application rate, and the ratio of root and shoot was highest under the treatment of W_1N_0. More than 85% of the wheat roots were distributed in 0-40 cm soil layer, and the yield was 0-40 cm soil RWD showed a significant linear regression relationship with RWD in 40 ~ 60cm soil layer.W_2 irrigation conditions could promote the distribution of wheat roots to the middle and lower layers (40-60 cm); irrigation and nitrogen application could significantly affect grain yield and biomass of spring wheat The yield and biological yield increased with the increase of nitrogen application rate and irrigation volume, and the grain yield was the highest in W_2N_2. The irrigation productivity decreased with the increase of irrigation rate, and the utilization rate of nitrogen fertilizer decreased with the increase of nitrogen application rate Under the condition of fixed ridge and ridge cultivation, under the condition of N 2 (180 kg · hm -2) and W 2 (2400 m -3 · hm -2), the growth of root system was promoted and then increased Spring wheat grain yield and water and nitrogen use efficiency, is a suitable water and nitrogen combination under fixed-field wheat cultivation in Hexi Irrigation Area.