Environmental Benefits of Olive By-Products in Energy, Soil, and Sustainable Management

This study aimed to evaluate the environmental benefits of utilizing by-products from olive farms and olive oil mills within the framework of sustainable resource management and the reduction in agricultural waste, through an integrated circular approach that involves composting and bioenergy recovery. A total of 10.7–11.2 t/ha of biomass, including pruning residues and olive pomace, was generated, with a utilization efficiency of 63.5–67.5%. The energy potential of olive biomass was highlighted through assessments that revealed a theoretical generation potential of approximately 96 GJ/ha (25–28 MW·h/ha), primarily from repurposed woody biomass and pomace. The environmental analysis showed a 50–60% reduction in greenhouse gas emissions compared to conventional disposal, due to avoided open burning, carbon stabilization via compost, and the displacement of fossil fuels. Economically, the circular strategy yielded a net benefit of ~70 $/ha, with revenues from bioenergy and compost exceeding processing costs. Soil organic matter increased from 1.3% to 1.5% after compost application, improving fertility and water retention. The waste reduction percentage reached ~65%, significantly decreasing the volume of unutilized biomass. These outcomes, confirmed through statistical and correlation analyses, demonstrate a robust model for circular agriculture that enhances energy self-sufficiency, mitigates the environmental impact, and supports economic and agronomic sustainability. The findings offer a replicable framework for transforming olive farming waste into valuable bioresources.