| The study aimed to investigate the effects of intercropping green manure on maize agronomic traits, yield, and soil total nitrogen under reduced irrigation conditions. To provide practical references for exploring the efficient production pattern of maize intercropping green manure with water resources carrying security in arid irrigation areas. Split-district experiment was conducted, the maize||common vetch (M||V) and monoculture maize (SM) two cropping patterns in the main district, and high (I3, 400 mm), medium (I2, 340 mm), and low (I1, 280 mm) three irrigation levels in the secondary district. The study monitored maize agronomic traits, yield, and soil total nitrogen content from 2020 to 2022. The findings indicate that: the M||V significantly enhanced maize plant height, stem thickness, and ear height, showing increases ranging from 6.3%-14.3%, 5.4%-12.0%, and 12.5%-22.1%, respectively, compared to SM. Moreover, intercropping led to improvements in maize spike length, spike thickness, number of rows, and number of grains per row increased by 5.7%-20.2%, 3.7%-13.6%, 2.7%-5.9% and 6.8%-17.7%, respectively. Compared to high irrigation, medium and low irrigation had adverse effects on monocropping maize the traits such as plant height, stem thickness, and ear height, with reductions ranging from 5.4%-13.1%, 3.3%-10.1%, and 7.9%-17.5%, respectively. Reduced irrigation led to decreases in maize spike length, spike thickness, number of rows, and number of grains per row by 4.7%-11.7%, 3.9%-9.0%, 2.2%-4.0%, and 4.5%-12.5%, the differences between medium and high irrigation in the intercropping were not significant for maize plant height, stem thickness, spike height, spike length, spike thickness, number of rows in the spike, and number of grains per row. M||V demonstrated significant yield improvements compared to SM, with increases in grain yield and biomass ranging from 7.7%-27.4% and 6.2%-19.2%, respectively. In monocropping, medium and low irrigation led to reductions in grain yield and biomass by 3.7%-19.3% and 3.7%-13.7% when compared to high irrigation. Interestingly, there was no significant difference between medium and high irrigation treatments in grain yield and biomass within the intercropping system. Intercropping also led to a notable increase in soil total nitrogen content in the 0~40 cm soil layer by 5.8%-7.9% when compared to monoculture. The study observed that intercropping common vetch had synergistic effects on enhancing soil total nitrogen content, leading to improvements in maize plant characteristics such as height, stem thickness, ear height, ear length, ear thickness, and ear rows. These enhancements ultimately increased the number of kernels in the ear and the 1000-kernel weight, ensuring that maize yield was maintained under medium irrigation (340 mm). Overall, intercropping common vetch under medium irrigation (340 mm) resulted in similar plant height, stem thickness, spike height, spike length, spike thickness, number of rows of spikes, and the number of rows of grains as those under high irrigation (400 mm), thus promoting overall growth and maintaining maize yield. Therefore, intercropping green manure can be recommended as an efficient production pattern for areas with limited irrigation. |