Chapter 5 - Reuse of olive mill waste as soil amendment

Abstract

The environmental impact of olive oil production is important as oil extraction can require a considerable amount of water and generates high quantities of olive mill wastes (OMW). In many olive-producer countries (e.g., Italy), OMW could be applied as amendment on the agricultural soils under specific requirements. Such application has raised interest not only because of its relatively low cost, but also for its potential to enhance soil fertility. Indeed, OMW high content in phosphorous, potassium, and organic matter could positively affect soil’s physicochemical characteristics improving crop productivity. However, OMW application to soils should be implemented with rationality since the high concentration of polymeric phenols have a well-known bacteriostatic effect on microorganisms and some phytotoxic effect on cultivations. In addition, a careful management of that application is required due to OMW acidic nature and high concentration in salts. In this chapter, the benefits and risks of using OMW as a soil amendment are discussed and recommendations on their proper application are also provided.