土默特平原灌区玉米种植普遍采用膜下滴灌模式，浅埋滴灌技术尚不成熟，为探究浅埋滴灌氮肥运筹对玉米农艺性状与产量的影响，本研究在不同氮肥用量（240 kg/hm2、300 kg/hm2、360 kg/hm2）下设置3个分次追施处理，分别为3次追施、5次追施、7次追施。结果表明：氮肥用量增加，株高、穗位高、叶面积指数（LAI）明显增加。240 kg/hm2氮肥用量下追施次数增加，株高、穗位高、LAI明显降低；300 kg/hm2、360 kg/hm2氮肥用量下，不同追施次数间吐丝期株高无明显差异，穗位高表现为7次追施大于3次追施。240 kg/hm2氮肥用量下，3次追施的干物质量较7次追施增加了4.57%-22.47%；300 kg/hm2氮肥用量下，3次追施的乳熟期干物质量较7次追施两年分别降低了6.65%和25.84%；360 kg/hm2用量下追施次数间干物质量趋势与300 kg/hm2类似。300 kg/hm2用量下分7次追施处理两年的玉米产量分别为15.07 t/hm2、15.21 t/hm2，与360 kg/hm2用量下产量无显著差异，较240 kg/hm2用量下分7次追施处理明显增加了4.5%、14.97%。土默特地区玉米无膜浅埋滴灌下可推荐生育期追施氮肥300 kg/hm2，分7次施入，节肥的同时保障高产。

Maize drip irrigation under mulch was generally adopted in the Tumote Plain irrigation area, while the shallow-buried drip irrigation technology was still not mature. To explore the effects of nitrogen fertilizer management on maize agronomic traits and grain yield, this study set up different dressing frequency treatments (3 topdressing, 5 topdressing, and 7 topdressing) under different nitrogen fertilizer levels (240, 300, and 360 kg/hm2). The results show that the maize plant height, ear height and leaf area index (LAI) increased significantly with nitrogen fertilizer rates increased. Under the nitrogen fertilizer application rate of 240 kg/hm2, the plant height, ear height and LAI decreased significantly with the number of topdressing applications increased. Under the nitrogen fertilizer application rates of 300 kg/hm2 and 360 kg/hm2, there were no significant differences in plant height at silking stage, but ear height of 7 topdressing was higher than that of 3 topdressing. Under the nitrogen fertilizer application rate of 240 kg/hm2, dry matter of 3 topdressing increased by 4.57%-22.47% compared with 7 topdressing. Under the nitrogen rate of 300 kg/hm2, dry matter of 3 topdressing decreased by 6.65% and 25.84% respectively compared with 7 topdressing at the milk-mature stage in two years. The trend of dry matter between the application times at 360 kg/hm2 was similar to that at 300 kg/hm2. The 7 top-dressing maize yields of 300 kg/hm2 were 15.07 t/hm2 and 15.21 t/hm2 respectively, were not significantly different from those of 360 kg/hm2, but increased significantly by 4.5% and 14.97% compared with7 top-dressing of 240 kg/hm2 in 2022 and 2023. It was recommended that 300 kg/hm2 nitrogen fertilizer application during the growth period, divided into 7 applications, can save fertilizer while ensuring high yields in shallow-buried drip irrigation in Tumote plain.

S274；S513

中央引导地方科技发展资金项目(2024ZY0038),集宁师范学院科学研究项目(jsky202225)