Effect of alternative organic fertilizers on the nutritional value and yield of head cabbage

Commercial brands of alternative, organic fertilizers were compared with conventional, mineral fertilizers using head cabbage. There were six different treatments: conventional farmyard manure, Agro (made from poultry bedding and molasses), Dvorecký agroferm (granulated, made from dried, aerobically-fermented farmyard manure), Agormin (an organo-mineral fertilizer), compost manufactured from plant waste material, mineral fertilizer, and an unfertilized control. All the treatments were applied at rates providing approximately the same level of nutrients. After harvest, the levels of the minerals (K, Na, Ca, and Mg), ascorbic acid, nitrates and yield were measured. There were no significant differences between the treatments in levels of K, Na and Ca in case of organic fertilizers (farmyard manure, Agro, Agormin and compost). The unfertilized control had the highest levels of ascorbic acid; it was significantly higher than in case of farmyard manure which, in turn, had significantly higher values than compost. Significant differences between the treatments were found in the levels of nitrates; the lowest in case of Dvorecký agroferm and in the control. The highest marketable yields were recorded with farmyard manure and Dvorecký agroferm, the latter being significantly higher than the control. This study shows that alternative, organic fertilizers (except compost) have similar qualities as farmyard manure.