Abstract:

The irrational application of chemical fertilizers is one of the major issues in China's agricultural environment. Exploring region-specific fertilizer reduction technologies, determining appropriate reduction ratios, and improving fertilizer use efficiency are of significant importance. In this study, the late rice cultivar Yongyou 1540 was used as experimental material. A field experiment was conducted with five treatments: no fertilization (CK), no nitrogen (N0), no phosphorus (P0), no potassium (K0), and optimized fertilization (NPK). The effects of different treatments on rice yield, nutrient uptake, and fertilizer utilization efficiency were investigated.The results showed that there was no significant difference in rice yield between CK and N0 treatments. Similarly, no significant differences were observed among P0, K0, and NPK treatments, but their yields were significantly higher than those of CK and N0. Compared with CK, the P0, K0, and NPK treatments increased rice yield by 25.1%, 22.2%, and 24.7%, respectively; straw biomass increased by 27.9%, 31.4%, and 25.0%, respectively; grain nitrogen content increased by 35.8%, 33.7%, and 37.4%, respectively; and straw nitrogen content increased by 102.4%, 60.7%, and 79.3%, respectively. The nitrogen, phosphorus, and potassium fertilizer use efficiencies were 44.9%, 8.9%, and 25.2%, respectively. This study demonstrates that, under the current experimental conditions, nitrogen is the decisive factor affecting rice yield, whereas phosphorus and potassium exhibit no significant yield-increasing effects. Future fertilization strategies should prioritize ensuring nitrogen supply while reducing phosphorus and potassium application rates.

Key words: fertilizer reduction, fertilizer utilization rate, optimized fertilization, rice yield, nutrient uptake