The article is devoted to researching the fertility of the soils served by the Chief Shirvan Collector in the Republic of Azerbaijan based on agrochemical indicators. For the purpose of research, cuttings were placed in characteristic places and soil samples were analyzed in the laboratory and agrochemical indicators were determined. Taking into account the change of parameters affecting productivity according to the stochastic scheme, the parameters were selected as primary and secondary parameters using the rules of Probability, Reliability theories and Mathematical Statistics, and the block diagram of productivity was built based on this. In the block diagram, the first-order elements are connected in series, and the second-order elements are connected in parallel. 0–25 cm according to the mathematical model according to the block diagram; 25–50 cm; The probability of soil fertility in 50–100 cm layers was determined as 0.46, 0.47 and 0.13, respectively. The obtained result shows that the soil fertility in the studied areas is very low.