Effect of Nitrogen Management Practices on Photosynthetic Characteristics and Grain Yield of Wheat in High-Fertility Soil

Abstract

The uneven soil fertility made it difficult to implement the recommended nitrogen (N) management practices in the North China Plain (NCP). In order to clarify the effect of N managements in high-fertility soil with a perennial wheat yield of 10,500 kg ha−1 on photosynthetic characteristics, grain yield, N agronomic efficiency (NAE), and water use efficiency (WUE), a trial was conducted from 2022 to 2024. Main plots were N rates of 0 (N1), 150 (N2), 210 (N3), and 270 (N4) kg N ha−1; The sub-plots adopted fertigation (F) and traditional fertilization method (T). The results showed that, compared with T, F increased the intercept rate of photosynthetic effective radiation of canopy, net photosynthetic rate, stomatal conductance, and transpiration rate of flag leaves, as well as the activity of phosphate sucrose synthase and sucrose content. It enhanced dry matter transport and contribution to grain. Under N2, the time required to reach the maximum grain filling rate, duration of grain filling and active grain-filling period of F were improved. Grain yield of N2 was increased by 27.81% and 6.75% compared to N1 and N3, respectively. NAE was improved by 48.63% and 51.47%, and WUE was improved by 20.71% and 9.85%. Therefore, the best effect was achieved by using fertigation and the N rate of 210 kg ha−1 in high-fertility soil.

Keywords

• high soil fertility field
• grain yield
• photosynthetic characteristics
• accumulation and remobilization of dry matter
• grain filling traits
• water and N use efficiency