Effects of different fertilizer combinations on yield and nitrogen use efficiency of summer maize in Jiangsu province

Rational application of nitrogen fertilizer plays a crucial role in promoting crop growth and increasing yields. The application of slow-release fertilizer has emerged as an important agronomic measure to increase yield and production efficiency further. In this study, a field trial with maize hybrid Jiangyu877 as material was conducted to investigate the effects of six fertilizer combinations [no fertilizer (P1), common nitrogen fertilizer application (P2), slow-release nitrogen fertilizer application (P3), common nitrogen fertilizer and slow-release nitrogen fertilizer 1:1 application (P4), 1:2 application (P5) and 2:1 application (P6)] on yield and nitrogen use efficiency. Fertilization significantly increased maize yield, with the best increase in the treatment combining common and slow-release nitrogen fertilizers. Among all treatments receiving equal amounts of nitrogen, the P5 treatment exhibited superior yield and higher nitrogen use efficiency than other treatments. Compared with the P3 treatment, the dry matter accumulation of P5 increased by 6.6 ~ 13.7%, nitrogen accumulation increased by 13.0 ~ 16.3%, and nitrogen use efficiency increased by 8.1 ~ 11.5%. Therefore, compared with the P3 treatment, the 1000-grain weight and the number of grains per panicle were significantly increased, the test increased yield by 2.6 ~ 4.5%, and the net income increased by 17.1%~80.4% in three years. In conclusion, in the actual production of summer maize in Jiangsu Province, under the planting density of 75,000 plants ha ^− 1 , the recommended fertilization method was common nitrogen and slow-release nitrogen (1:2) (common nitrogen 75 kg ha ^− 1 : slow-release nitrogen 150 kg ha ^− 1 ) one-time base application, which synergistic improvement of yield and efficiency could be realized.