The changes of soybean protein and oil content were studied on chernozem soils in different crop years (2017–2019), for two genotypes (Pannónia kincse, Boglár), under different agrotechnical conditions (irrigation, fertilization). Soybean content values were influenced differently by crop year, agrotechnical elements, and genotype. The protein content decreased in the crop year with a favorable water supply (33.83–38.53% in 2019), while higher protein content was measured in the drier (34.93–41.13% in 2017) and warmer years (22.60–40.17% in 2018). As a result of fertilization, the protein content of soybean varieties increased by 1.5–4.7% in absolute terms. Of the different agrotechnical factors, a moderate positive correlation (0.515**) was detected only between fertilization×protein. Irrigation increased protein content only in the dry crop year (2017). There was a difference in the protein content of the two genotypes, i.e. the protein content of the Pannónia kincse variety significantly exceeded the values of the Boglár variety by 0.4–4.1% in absolute terms. The crop year did not affect the oil content of soybeans (21.43–23.63% in 2017, 21.77–23.50% in 2018, 19.10–21.90% in 2019). Fertilization reduced the oil content by 0.1–1.1%, while irrigation did not affect it. There was no significant difference in oil content between the examined varieties. PO values (protein%+oil%) exceeded 60 in 2017 and 2018 in the N140+PK high-dose fertilizer treatment, while they ranged from 56 to 59 in 2019.