The limited availability of water resources severely restricts agricultural development in the semiarid and arid regions of Northwest China. A two-year field experiment was conducted to investigate the effects of irrigation and planting density on the soil water content (SWC), growth and development, yield, water use efficiency (WUE) and economic benefits of spring maize in arid areas under mulch drip irrigation system. The optimized combination of irrigation and planting densities for high grain yield, WUE and net return were obtained by multiple regression analysis. Experiment included three irrigation treatments (HI: 450 mm; MI: 337.5 mm; LI: 225 mm) and four planting densities (D1: 75,000 plants ha⁻¹; D2: 90,000 plants ha⁻¹; D3: 105,000 plants ha⁻¹; D4: 120,000 plants ha⁻¹). The results showed that the reduction of irrigation decreased SWC, leaf area index (LAI), aboveground biomass, yield and evapotranspiration (ET), but improved WUE. HI and MI were significantly different from LI. Increasing planting density increased LAI and ET, but reduced SWC and aboveground biomass. Planting density had significant effects on yield and WUE, which differed in both years. The overall yield, WUE and net return were greater than the two-year average of HI-D1 under an irrigation amount of 271.9–500.2 mm and a planting density range of 7.1–14.3 × 10⁴ plants ha^-1. MI-D2, with 25 % reduced irrigation, increased the two-year average yield, WUE and net return by 5.2 %, 20.2 % and 27.2 %, respectively, compared to HI-D1. Therefore, irrigation of 337.5 mm at a medium planting density of 90,000 plants ha^-1 under mulch drip irrigation is recommended for spring maize production in the drylands of Northwest China in our research.

水资源有限，严重制约了西北半干旱和干旱地区的农业发展。进行了为期两年的田间试验，以研究灌溉和种植密度对覆盖膜下滴灌干旱地区春玉米土壤水分（SWC），生长发育，产量，水分利用效率（WUE）和经济效益的影响。灌溉系统。通过多元回归分析，获得了高密度灌溉与种植密度的组合，以实现高谷物产量，水分利用效率和净收益。实验包括3种灌溉处理（HI：450 mm; MI：337.5 mm; LI：225 mm）和4种种植密度（D1：75,000株ha ^-1 ; D2：90,000株ha ^-1 ; D3：105,000株ha ^-1; D4：120,000植物ha ^-1）。结果表明，减少灌溉可降低水质系数，叶面积指数（LAI），地上生物量，产量和蒸散量（ET），但提高了水分利用效率。HI和MI与LI显着不同。种植密度的增加增加了LAI和ET，但减少了SWC和地上生物量。种植密度对单产和WUE有显着影响，这在两年中都不同。在271.9–500.2 mm的灌溉量和7.1–14.3×10 ⁴种植面积ha ^-1的灌溉量下，总产量，WUE和净收益均高于HI-D1的两年平均值。。与HI-D1相比，MI-D2的灌溉减少了25％，两年平均产量，WUE和净收益分别增加了5.2％，20.2％和27.2％。因此，在我们的研究中，建议在覆盖滴灌条件下以中等种植密度90,000株ha ^-1进行337.5 mm的灌溉，以便在西北干旱地区生产春玉米。