Morphological and dimensional traits in vegetables: raised bed vs. flat soil

The quick dynamics of the vegetable production sector, characterized by rapid cropping successions and species with very different cultural needs, usually results in intensive soil tillage and management. These processes are necessary to ensure the best conditions for the crop and adequate development throughout the crop cycle from sowing, or transplanting, to harvest. Different types of soil tillage are often used in the creation of raised seed- or transplant beds. The reported experiment was aimed at evaluating the effect of raised beds, in comparison to traditional soil management, on the morpho-dimensional traits of different vegetable species. Seven vegetable crops were considered: lettuce, zucchini, green beans, rocket salad, variegated-leaved Italian chicory, long-stemmed Italian chicory and chard, transplanted and seeded in raised beds and on flat soil. At marketable size the crops were harvested and sampled in order to evaluate morphological and dimensional characteristics specific for each crop including the root system. Results showed the positive effect of raised beds, especially for transplanted crops (lettuce and zucchini), which increased yield by more than 15% in the first case. Direct sown crops were more variable. Positive results for raised bed were recorded for rocket salad, with a weight gain of the aerial part higher than 50%; whereas green bean did not respond significantly to soil tillage. The tillage effect was also significant on root system dimensions that, in the case of beds, was generally higher compared to the flat soil.