Abstract:

To investigate the responses of yield and nutrient use efficiency of different rice varieties to the “one-basal-one-topdressing” fertilization mode，field experiments were conducted with two rice varieties，Huruanyu 1 and Sujing 4699. Two treatments were established：conventional fertilization mode（T1）with broadcasting of basal fertilizer，tillering fertilizer，and panicle fertilizer，and the “one-basal-one-topdressing” mode（T2）with side-deep basal fertilization and broadcasting of panicle fertilizer. The yield，yield components，panicle setting rate，and nutrient use efficiency were compared between treatments. The results showed that under T2，the yields per 667 m² of Huruanyu 1 and Sujing 4699 were 623.5 and 611.8 kg，respectively，with no significant difference from T1. The panicle setting rate under T2 were 76.5% for Huruanyu 1 and 70.1% for Sujing 4699，which were significantly increased by 6.6 and 6.9 percentage points compared with T1. Regarding fertilizer use efficiency，T2 significantly increased the uptake of nitrogen，phosphorus，and potassium，as well as grain production efficiency and dry matter production efficiency for both varieties. Specifically，the partial factor productivity of nitrogen fertilizer for Huruanyu 1 and Sujing 4699 under T2 increased by 40.7% and 20.3%，respectively，compared with T1；that of phosphorus fertilizer increased by 307.3% and 249.3%，respectively，and that of potassium fertilizer increased by 103.8% and 74.6%，respectively. Variety comparison indicated that Huruanyu 1 exhibited generally higher nutrient use efficiency than Sujing 4699 under T2. In conclusion，the “one-basal-one-topdressing” mode with side-deep basal fertilization and broadcasting of panicle fertilizer can achieve both stable rice yield and improved nutrient uptake and utilization even under reduced N，P₂O₅，and K₂O application rates. This mode is more suitable for high-efficiency production of Huruanyu 1. For Sujing 4699，it is suggested to appropriately reduce the proportion of basal nutrients to control unproductive tillers and increase the amount of panicle fertilizer to promote the formation of productive panicles，thereby further improving its yield stability and nutrient use efficiency.

Key words: rice, fertilization, yield, nutrient use efficiency, variety