[A comparison of selected parameters of potatoes health quality from ecologically oriented and conventional farms].

The aim of work was to compare nutritional quality and wholesomeness of the potatoes from ecological (ECO) and conventional (CONV) farms. Other aim was to check if the west-european data telling about better nutritional quality of ECO potatoes can be confirmed in Polish agricultural conditions. Nine ECO farms located in Toruń and Sieradz provinces, having EKOLAND's certification were selected to study. A neighbour CONV farm with similar production conditions was selected to each ECO farm. ECO farmers manured potatoes with composted cow manure or compost giving on average 30 t/ha. CONV farmers used mineral fertilizers NPK in 1:1:1,5 ratio giving 100 kg N/ha. In the autumn several compounds were determined in potatoes: the contents of dry matter according to PN-88/R-04013, the contents of nitrates and nitrites according to Draft International Standard ISO, the contents of Pb and Cd by means of ASA method and the contents of vitamin C as L-ascorbic acid according to PN-90/A-75101/11. The ECO potatoes contained in both years significantly less nitrates than CONV potatoes. In 1992 the nitrates contents was much higher in both kinds of potatoes than in 1993. The nitrites contents was in both years higher in CONV potatoes but the difference was statistically significant only in 1993. The lead contents was low in both kinds of potatoes and didn't exceed permissible level. The cadmium contents was in 1992 significantly higher in CONV tubers than in ECO tubers and exceeded permissible level. In 1991 and 1993 both kinds of tubers contained similar cadmium levels. The contents of dry matter and vitamin C was similar in both kinds of tubers. The study has shown that ECO potatoes were more wholesome than CONV potatoes. The results obtained in Polish agricultural conditions confirmed west-european data.