Evaluates relations existing between intensified crop production, with emphasis on the use of fertilizers, and the increasing content of nitrates in drinking water resources. Using a given area, it specifies the farmland affected by hydrological interests and quantifies the theoretical drop in crop production when the application of fertilizers has been restricted. From the production proportions found the mutual relationship and influence on the production agricultural function, as well as the specific hydrological functions of the examined area are derived.