YIELD AND SOIL RESPONSES OF MELON GROWN WITH DIFFERENT ORGANIC FERTILIZERS

A three-year field experiment (2006–2008) was carried out in Mediterranean conditions to study the effects of organic fertilizers application on yield performance and plant nitrogen (N) status of melon crops. Soil properties at the end of experiment were further investigated. In a strip-plot experimental design, two irrigations and the following four fertilizer treatments were compared: mineral fertilizer (Min); commercial stable manure (Org); anaerobic digestate (WDD); composted municipal solid organic wastes (SUW). The results showed no statistical differences among the four different treatments on melon yields. Conversely, the highest irrigation treatment showed a significantly higher total yield (34%) and fruits number (26%). During cropping cycles, the Min treatment reached the highest mean nitrate content with an increase of about 59% and 154% respectively compared with Org and mean of WDD and SUW. The WDD and SUW significantly increased soil total, extracted and humified organic carbon of the 14, 22 and 12% compared with Min. Among treatments, no significant difference was found for heavy metals excepted for Cu, which reached the highest level in WDD treatment.