Objective The aim is to explore the application of“big formula and small adjustment” in rice production under the light and simple nitrogen application management pattern, in order to realize the goal of precise fertilization in rice.

Methods “Meixiangzhan No.2” was selected as the experimental material, and a randomized block design was employed to conduct field experiments for rice cultivation. In the early season of 2022, six treatments were set up, namely, large and small formulations (ZMP1 and ZAP1) for high nitrogen-fertile plots, large and small formulations (ZMP2 and ZAP2) for medium nitrogen-fertile plots, and large and small formulations (ZMP3 and ZAP3) for low-nitrogen-fertile plots. In the late season of 2022, six treatments of large and small formulations (WMP1 and WAP1) in high nitrogen fertility plots, large and small formulations (WMP2 and WAP2) in medium nitrogen fertility plots and large and small formulations (WMP3 and WAP3) in low nitrogen fertility plots were also set up to investigate the effects of light and simple application of nitrogen in large and small formulations on major physiological indices and yield components of rice.

Results Under the condition of equal nitrogen level, the effects of large and small formulations on rice leaf area index, inverted 4-leaf SPAD value and effective number of spikes at the early stage of young spike differentiation were significantly different (P<0.05), and there was no significant difference in the effects on rice yield (P>0.05). Among them, the leaf area index, inverted 4-leaf SPAD value and effective number of spikes of early rice of large formula were 4.30%, 3.84% and 3.39% higher than those of small formula, respectively. The three indices of late rice of large formula were 12.31%, 3.15% and 1.97% higher than those of small formula, respectively. Under different nitrogen levels, the aboveground dry matter accumulation of rice with high nitrogen level was higher than that with low nitrogen level at the early stage of young spike differentiation, while the fruiting rate and thousand-grain weight were lower than that with low nitrogen level at the later stage, and there were significant differences in multiple comparisons (P<0.05), but there was no significant difference in the t-tests between the large and the small formulas at the same nitrogen level (P>0.05).

Conclusion Using the nitrogen fertilizer transport method of light and simple nitrogen application, the large and small formulations had different effects on the growth rhythm and yield composition of rice, but there was no significant effect on yield. Fertilizer application of small formulations was more precise and yield was stable, which has the value of popularization and application.