Summary:

Nowadays in Poland as well as in many parts of the world a number of research, aiming at comparing the quality of raw material produced by organic and conventional agriculture is being conducted. Relating to that, in this study the size and quality of potato tubers, wheat grains and carrot roots cultivated in two agricultural systems: organic and conventional have been compared. Research has been performed on raw material samples, gathered from five production fields located in the Kuyavian-Pomeranian Voivoidship (in years 2010-2012), two of which have been organic while three conventional. The representative samples of plants considered in study were analyzed for the content of: total protein in winter wheat grains and nitrates(V) and starch in the fresh mass of potato tubers and carrot roots. According to obtained results the yield of starch and total protein has been calculated. Conducted studies have proved that the yield and the amount of total protein in carrot roots, wheat grains and potato tuber varied depending on different agricultural system. The highest yield have occurred in conventionally farmed crops. Total protein content was highest in organically farmed carrot roots, while the highest nitrates(V) level was detected in conventionally farmed potato tubers. Wheat from conventional farming had only trace amounts of nitrates(V). The starch content of the organic system in carrot roots and potato tubers was higher compared to the cultivation of such crops conventionally grown.