Use of Composted Olive Waste as Soil Conditioner and its Effects on the Soil

摘要

The protection of agro-ecosystems necessitates the use of soil management techniques targeted to fertility preservation. This study was aimed to assess the cumulative effect of mineral fertilization and of the incorporation of increasing doses of composted olive pomace on the sandy-loam soil. The trial involved a split-plot design with 3 replicates and was aimed at comparing 2 types of compost (in large plots), the untreated control (0), mineral fertilization (Min), the conditioner made from composted olive pomace at the rates of 15-30-45-60 mg ha-1 of dry matter and the integration of 30 mg ha-1 with ? of the N rate used for the Min treatment. As compared to the non-conditioned soil, the spreading of 60 mg ha-1 leads to increase organic matter by 100%, total nitrogen by 1.29 g kg-1, available phosphorus by 11.5 g kg-1, exchangeable potassium by 251 mg kg-1. Moreover, the land spreading with increasing doses of olive pomace seems to increase the structure stability index (+71% without pre-treatment and+30% with alcohol pre-treatment) favoring particle aggregation. This leads to improve pore distribution, which is extremely important for hot arid environments where soils have depleting organic matter levels so they are more and more de-structured. The application of composted olive pomace as fertilizer has been an effective alternative to mineral fertilization and a valuable tool to achieve a threefold objective: storing carbon in the soil, improving soil quality and reducing the environmental impacts associated with the disposal of organic materials.