The article discusses the problems and substantiates the need to take into account environmental factors in the state cadastral assessment of agricultural lands. A Methodology for calculating the environmental factor is presented. Such factor is considered as the economic equivalent of the restoration and improvement of the fertility in terms of expenses for bringing a land plot to the state of maximum use efficiency; the aim of the process is eliminating the negative consequences of an irrational use of land plots. The calculation of the expenses for bringing a land plot to the state of maximum use efficiency was carried out on the example of a land plot located in the Moskalensky District of the Omsk Region. Recommendations are given for improving the methodology for calculating the cadastral value of agricultural lands as regards farmlands by taking into account the level of expenses for bringing a land plot to the state of maximum use efficiency.