Recent studies on preparation of humified compost using olive mill waste for horticultural purposes

This paper is a brief review of recent studies on the feasibility of using olive mill solid waste (OMW) as a major ingredient in the preparation of humified compost (HC), and the application of the HC to soil on the growth of horticultural crops such as Olea europaea (olive), Lycopersicon esculentum (tomato), Lactuca sativa (lettuce), Fragaria vesca (strawberry) and Agaricus bisporus (white button mushroom). OMW-based compost subjected to thermal composting process resulted in significant decrease in the level of polyphenols making it non-phytotoxic. Addition of the compost to olive orchard soil significantly increased total organic carbon and humic substances by 40% and 58% respectively. Similar results on elevated nutritional status and enhanced crop productivity were obtained in trials with other horticultural crops and the cultivated mushrooms. The outcomes of these studies have been the integration of soil health and environmental management practices to achieve sustainable crop production.