Recommended Fertilization Rates of Nitrogen, Phosphorus, and Potassium Fertilizers for Next Generation Dryland Rice Based on a “3414” Fertilizer Experiment

Purpose This study aimed to analyze the effects of different nitrogen (N), phosphorus (P), and potassium (K) fertilization rates on agronomic traits, yield, nutrient uptake, and rice blast incidence of next generation dryland rice (NGDR), thereby providing a scientific basis and data support for its rational fertilization of NGDR.

Methods A “3414” soil testing and formulated fertilization experiment was conducted in Lancang Lahu Autonomous County, Yunnan Province, using the rice variety Dianheyou 615. Measurements and statistics were collected on the agronomic traits, yield, nutrient uptake, and rice blast incidence of NGDR. Using the quadratic function and the trivariate quadratic function for fertilizer effect, the recommended fertilization rate for NGDR in the Lancang mountain area was proposed.

Results Fertilization improved the biomass and grain yield of NGDR. The N₂P₂K₁ treatment (N 45.00 kg/hm², P₂O₅ 45.00 kg/hm², K₂O 22.50 kg/hm²) achieved the maximum biomass, while the N₂P₁K₁ treatment (N 45.00 kg/hm², P₂O₅ 22.50 kg/hm², K₂O 22.50 kg/hm²) produced the highest grain yield. In terms of nutrient uptake, the N₂P₂K₂ treatment (N, P₂O₅, and K₂O were all 45.00 kg/hm²) exhibited the optimal comprehensive nutrient absorption performance. In addition, the N₀P₂K₂ treatment (N 0.00 kg/hm², P₂O₅ 45.00 kg/hm², K₂O 45.00 kg/hm²) had the lowest incidence of rice blast disease.

Conclusion Based on the trivariate quadratic fertilizer effect function, the economically optimum fertilization rates for NGDR grown under environmental conditions in the Lancang mountain area of Lancang are N 31.96 kg/hm², P₂O₅ 55.94 kg/hm², and K₂O 52.66 kg/hm², corresponding to an optimal economic grain yield of 6031.81 kg/hm².