Objectives In the past 25 years, agricultural technology has advanced rapidly. Studying the changes in fertilizer application amount, yield, nutrient uptake and fertilizer use efficiency of rice in Heilongjiang Province can provide technical support and theoretical basis for the efficient application of fertilizers.

Methods A total of 255 rice field experiments from 1999 to 2023 were collected, and the fertilizer application rate, yield, nutrient uptake, and fertilizer use efficiency data were extracted from 5 treatments like CK, NP, NK, PK and NPK, and 1130 sets of data were obtained. Each 5-year period was designated as a stage (Ⅰ, Ⅱ, Ⅲ, IV, V). A total of 1,130 sets of data on fertilizer application rates, yields, nutrient uptake, and fertilizer use efficiency for each treatment were compiled.The changes in rice yields and fertilizer use efficiency in Heilongjiang Province, as well as their driving factors were analyzed.

Results From 1999 to 2023, the rice yield under NPK treatment in Heilongjiang Province showed a fluctuating yet upward trend, averaging 8,434 kg/hm² annually with an average yearly increase of 1.6%. Compared with NPK, the yields in PK, NK, NP and CK treatments were annual reduced by 37.0%, 15.1%, 13.7% and 38.0% respectively (P<0.05). The fertilizer application rate of rice demonstrated a slightly fluctuating upward trend. The average fertilization rates of N, P₂O₅ and K₂O were 137.2, 66.5 and 78.4 kg/hm² respectively, with annual average increases of 1.8%, 2.9% and 2.0% respectively; the economic optimal fertilization rates for rice were N 133.9, P₂O₅ 63.7, K₂O 74.2 kg/hm², with the ratio of N∶P₂O₅∶K₂O at 2.1∶1∶1.2. The uptake amounts of N, P and K nutrients in rice under NPK treatment showed a slightly fluctuating upward trend.The average uptake of N, P₂O₅ and K₂O was 133.1, 55.3 and 126.9 kg/hm², with an average annual increase of 2.4%. 2.6% and 1.7%, respectively; while the nutrient uptake of rice plants in PK, NK, NP and CK treatments were significantly reduced, relative to NPK treatment. The yield of rice was positively (P< 0.05) correlated with the uptake of N, P and K by the plants, and the degree of correlation was N>P>K. The nutrient recovery rates, agronomic efficiency and partial productivity of N, P and K in rice showed a slightly fluctuating upward trend. The average N recovery efficiency, agronomic efficiency, and partial productivity of nitrogen fertilizer were 37.6%, 25.8 kg/kg, and 66.1 kg/kg respectively, with an average annual increase of 0.3%, 2.6%, and 0.1% respectively. For P fertilizer, the corresponding values were 25.0%, 32.7 kg/kg, and 135.4 kg/kg, respectively, with annual average increases of 0.4%, 2.9%, and 1.5%, respectively; and for K fertilizer, they were 46.1%, 24.2 kg/kg, and 115.9 kg/kg respectively, with an average annual increase of 0.7%, 3.8%, and 1.8% respectively.

Conclusions Over the past 25 years, the rice yield, fertilizer application rate, nutrient uptake amount and fertilizer use efficiency in Heilongjiang Province had kept increased with fluctuations, the optimal economic fertilization rates stand at N 133.9, P₂O₅ 63.7and K₂O 74.2 kg/hm², maintaining a ratio of N∶P₂O₅∶K₂O at 2.1∶1∶1.2. The increase in fertilizer application rate, nutrient uptake and the improvement of fertilizer use efficiency have been the key factors contributing to the increase in rice production.