**5.5. General findings**

In the experimental conditions of southern Italy, the findings of the studies on repeated applications of WW indicate that it could be possible both to sustain herbaceous crops performance and support soil fertility, valorizing these wastes as organic amendment and reducing the risks of soil degradation, giving also a useful practice to reuse purposes as EU provides.

Also the composting experiences of olive mill and olive orchard wastes carried out in natural conditions, demonstrate as relatively easy feasible and noticeable effective the production of stabilized organic amendment of elevated agronomic value to very contained costs. These materials have their natural utilization to maintain soil organic fertility, as well as substrate for olive nursery, in perspective as substitute of peat. According to the modern principles of the energetic and economic sustainability of agro industrial processes, the olive mill and olive orchard wastes composting has been confirmed as a valid alternative to the raw waste water and pomace shedding on the soil. In particular, a higher efficiency was found in stabilizing the organic matter, which works better in the restoration and in longterm maintenance of soil fertility. Furthermore must be considered that the nutritional effect of compost can allow to reduce the use of chemical fertilizers in fertilization plans, mostly raising the value of this kind of agro industrial by-products management. So could be a better solution also to fit EU prescriptions concerning wastes reuse.
