Objectives Fertilization in cucumber production is commonly characterized by high application rates and imbalances, significantly affecting cucumber yields and fertilizer use efficiency in China. Determining nutrient requirements is a prerequisite for establishing scientific and effective fertilization recommendations for cucumbers and serves as the foundation for precise fertilization, which is crucial for sustainable cucumber production in China.

Methods We collected and summarized data from field experiments conducted by the International Plant Nutrition Institute (IPNI), the China National Knowledge Infrastructure (CNKI) database, and our research team in major cucumber-producing regions of China, using keywords such as “cucumber”, “cucumber + yield”, and “cucumber + nutrient absorption”. The QUEFTS model was applied to estimate optimal nutrient requirements for cucumbers at different target yields. Field experiments were conducted in Tianjin, Beijing, Hebei, and Jiangsu to validate the model-derived nutrient requirements for cucumbers.

Results The average cucumber yield reached 86.2 t/hm² but varied widely, ranging from 2.9 to 339.5 t/hm². The average N, P, and K absorption by cucumber fruits were 175.6, 44.1, and 236.6 kg/hm², respectively, with ranges of 44.8−459.0, 16.0−119.6, and 34.7−554.8 kg/hm², respectively. The average total N, P, and K absorption by the aboveground parts were 260.6, 64.7, and 326.9 kg/hm², respectively, with ranges of 52.0−525.3, 11.2−146.4, and 53.0−632.4 kg/hm², respectively. Differences in climate, soil conditions, cucumber varieties, irrigation amounts, and nutrient management practices across different planting areas contributed to the high variation in yields and nutrient absorption. By excluding the top and bottom 2.5% of nutrient internal efficiency values, we obtained the maximum dilution boundary (d) and maximum accumulation boundary (a) parameters. Using the QUEFTS model to simulate optimal nutrient requirements for cucumbers at different target yields, we found that for every 1000 kg of cucumber produced, the aboveground nutrient requirements were 2.25 kg of N, 0.48 kg of P, and 2.84 kg of K, with corresponding nutrient internal efficiencies of 444.9, 2074.3, and 352.1 kg/kg for N, P, and K, respectively. Field validation experiments showed that the simulated and measured nutrient absorption values for N, P, and K were consistent, with fitting index (d) values of 0.996, 0.978, and 0.997, respectively.

Conclusions The QUEFTS model was used to simulate optimal nutrient requirements for cucumbers at different target yields, establishing a quantitative relationship between cucumber yield and nutrient absorption in China. This provides nutrient requirement parameters for the establishment of recommended fertilization methods for cucumbers in China.