Quality differences between organic and conventional field grown vegetables - experiences from a Swedish long-term field trial

There is a debate regarding differences in quality between conventionally and organically grown vegetables. Sometimes the arguments are ideology driven rather than fact based. It is complicated to compare trials performed with different cultivars grown under different climate and management conditions. Usually the results are hard to generalize. To get rid of some of the confounding factors, a long-term crop rotation trial has been performed at Önnestad in southern Sweden. A number of conventional and organic rotations have been grown at the same site for more than 25 years (started in 1987). Some of the rotations contain field grown vegetable crops. In order to evaluate the impact on produce quality samples of carrots (Daucus carota) (1 conventional, 2 organic rotations), beet root (Beta vulgaris) (1 conventional, 1 organic rotation), potato (Solanum tuberosum) (2 conventional, 1 organic rotation) and onion (Allium cepa) (1 conventional, 2 organic rotations) were collected in 2014 and 2015. Yield was documented at harvest. Samples were frozen for soluble solids content analysis and freeze-dried for dry matter content determination. In general quality differences were small and inconsistent when the vegetables from the different crop rotations were compared. The largest differences were found between years, but the different crops did not respond in the same way.