Agrochemical Nitrogen Cycles, Photosynthesis Performance of Nitrogen Use Efficiency, and Yield of Maize

Nitrogen (N), as a macro-element, plays a vital role in plant growth and development. N deficiency affects plant productivity by decreasing the photosynthesis, leaf area, and longevity of green leaf. The experimental design was a randomized complete block design with four replicates: N0 (0 kg N ha−1), N90 (90 kg N ha−1), N180 (180 kg N ha−1), and N210 (210 kg N ha−1), respectively, i.e., the effects of different N application levels on photosynthetic physiology, leaf characteristics, yield, and production. The findings of the present study underscore the importance of optimizing nitrogen application to maximize light capture, photosynthetic efficiency, and crop productivity. Under N-treated groups (N90, N180, and N210), the average photosynthetically active radiation (PAR) of panicle leaves at all levels, N210, was determined to be higher than that of other treated groups, as well as the N0 level and the upper, middle, and lower regions of N0, N90, and N180 plants under the same leaf area index (LAI), and it was noted to be higher under N210, respectively. Dry matter accumulation under N180, and N210 increased, respectively, and under N210, the dry matter accumulation of the population was significantly higher than that under N180, respectively. The nitrogen use efficiency (NUE), nitrogen recovery efficiency (NRE), nitrogen internal efficiency (NIE), and partial factor productivity of nitrogen (PFPN) under different nitrogen (N) application rates were significantly higher than N0, where the NIE of N180 was significantly higher than that of N210, the NUE and NRE of N180 and N210 were higher than those of N0, and the difference from PFPN was not significant, respectively.