Known data relative to nitrate levels in leaf vegetables can hardly be compared. In fact, results may be
influenced by a large number of parameters (temperature, brightness, types and amounts of fertilizers
and/or manure employed in soils, characteristics and composition of irrigation water and/or of nutritive
solutions used for basin growing, variety of vegetable grown, etc.). All these parameters play an important
role as far as plant metabolism is concerned and therefore may significantly influence nitrate heap. Our
research has been carried on for two years in a row; nitrate levels, color and firmness have been determined
in wild rocket and leaf lettuce grown by employing different techniques in some farms of the Friuli Venezia
Giulia region. Furthermore, total N, total P and total K have been determined in samples of soils and of
nutritive solutions.
