The ultimate goal of application of yield maps is profitable crop output in many farming systems. Yield maps are the starting point in the precision farming system, and provide the final record indicating the effectiveness of any management changes.

Researches on yield mapping shown, that positions and boundaries of zones with different levels of yield change grossly from year to year.

Recently several methods and tools have been developed to generalization of a long-standing data on yield mapping. However, the applications of there methods are often troublesome when we try to take into account effects of external weather in any year or violating the agro rules on any locations of field during one or another year of observations.

This paper presents methodology of evaluation of yield maps using fuzzy indicators, which gives opportunity to to take into account an atypical phenomena and expert opinions.