| To clarify the response of maize growth and yield to intercropping fresh peas and biochar under nitrogen reduction, and to provide practical basis and theoretical support for the research and development of biochar enhancement technology for nitrogen-saving effect of intercropping fresh peas with maize. The study was conducted in 2022-2023 using a split-zone experiment, with the main zone being maize intercropped with fresh peas (M||P) and monocropping maize (SM), the split zones being the locally recommended nitrogen application (N1,360 kg N·hm-2), 30% reduction in nitrogen application (N2,250 kg N·hm-2), and the split zones being the application of biochar (C) and no biochar (A), to investigate the effects of biochar and intercropped with fresh peas on maize photosynthesis sources, dry matter accumulation, and yield. The results showed that under the reduced N application, intercropping fresh pea with biochar application could result in higher LAI in the pre-growth period of maize, and compared with the single crop of maize without biochar under the locally recommended N application, the LAI at 90-150 d after seedling emergence of maize and maize LAD at the whole reproductive stage were significantly increased by an average of 11.1% and 10.8%, respectively, which effectively slowed down the decrease of maize LAI and significantly increased maize LAD at the whole reproductive stage. This effectively slowed down the decrease of maize LAI and significantly increased maize LAD during the whole reproductive period. The intercropping of maize with fresh peas with biochar under reduced N application increased maize dry matter accumulation and dry matter accumulation rate by 13.0%, 15.3% and 16.2%, 19.5% at 60-90 d post emergence and 90-150 d post emergence, respectively, compared with monocropping maize without biochar under locally recommended N application rates. Maize grain yield of M||PN2C treatment was significantly increased by 6.3% and 17.8% (P<0.05) compared with M||PN1A and SMN1A treatments, respectively, and was not significantly different from that of M||PN1C treatment. Maize 1000-kernel weight in intercropping increased by an average of 5.2% compared to monocropping, and biochar could increase the number of ears and 1000-kernel weight of maize at a reduced level of 30% N application, and there was no significant difference in the number of ears and 1000-kernel weight of N2 maize under maize intercropped with fresh pea with biochar treatment compared to N1. Analysis by yield components and throughput showed that intercropped fresh pea with biochar was able to achieve a higher level of grain yield under nitrogen fertilizer reduction by increasing 1000-kernel weight of maize under nitrogen reduction, thus intercropped maize with biochar. The maize yield of the M||PN2C treatment was significantly higher than that of the SMN1A treatment and obtained a yield level that was not significantly different from that of the M||PN1C treatment, so that the M||PN2C treatment can be used as a reference for the nitrogen-saving and high-efficiency production model of the arid oasis irrigation area in this experiment. |