The present study is part of a medium-term experimental series launched in 2006 and aimed at developing a suitable cropping system for organic vegetables under the Mediterranean climate. A split plot design was adopted for testing the effect of three soil building crops (bean, pea and zucchini) and of two types of organic fertilizer (FertiCompost and AlterOrga) on the growth, yield, and fruit quality of melon as the main crop. Organic fertilizers were applied as liquid and solid forms. Zucchini, bean, and pea yielded 40, 6, 3.5 ton/ha respectively, and melon about 32 tons/ha with no significant difference between SBCs and organic fertilizers. Leaf mineral analysis showed higher calcium concentration in melon tissues when preceded by pea as soil-building crops.
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Higher potassium content was also found in residues of melon after zucchini and fertilized by AlterOrga, and lower nitrogen in those after bean. At the end of the 30-week rotation, soil nitrogen level increased by 0.02% in pea plots. In addition, lower pH was associated with AlterOrga. Zucchini reduced weed emergence by 48%, while bean reduced by 45% and pea by 25% throughout the two cropping seasons. The highest gross margin was gained from zucchini-AlterOrga (55.06 euro/subplot), and the lowest from pea-AlterOrga (5.64 euro/subplot).