The effect of Long-Term Fertilization on Soil Agrochemical Properties has been studied in a strila started in 1971 In both 1971 and 2021, the application of mineral NPK fertilizers increased the yields of winter wheat, spring barley, sugar beet, and other crops by 21.5-47.0 GJ ha?¹. The average annual nitrate leaching without N fertilization was 68 kg ha?¹, while an N216 rate increased N loss to 299 kg ha?¹. When N216 was applied without K and P fertilization, N loss increased to 510 kg ha?¹. After 50 years, a P50 fertilization rate did not change the concentration of soil mobile P2O5, while a P95 rate increased P2O5 content by 324 kg ha?¹, and a P180 rate increased it by up to 529 kg ha?¹. On loamy soil, even at the highest fertilizer rates, soil phosphate (PO4) leached down to a depth of 40 cm, amounting to 4.2-4.9 kg ha?¹, while potassium ion (K?) loss was up to 6.8-8.0 kg ha?¹. At optimum fertilization rates, the leaching was only one-third of these amounts. For soils with moderate concentrations of mobile P and K, the optimum rate of fertilizers in crop rotation is N 108, P 64, K 96.