Vincent de Leijster

60 Chapter 4 and reduce soil erosion by 51-95% (Durán Zuazo and Rodríguez Pleguezuelo, 2008; Martínez- Mena et al., 2019). The effects of agroecological management on farm’s economic performance metrics, such as management and investment costs, labor, and long-term profitability is barely known, as economic assessments tend to be limited to crop yields disregarding management costs and externalities (Bommarco et al., 2013). Examples of such studies on agroecological management and crop yields in Mediterranean tree-crops reported trade-offs between understory vegetation covers and crop productivity (De Leijster et al., 2019; Martin-Gorriz et al., 2020; Martínez-Mena et al., 2013). Another study showed that the implementation of no tillage with natural understory vegetation in a Spanish almond plantation reduced yield by 63% compared to conventional tillage management (Martin- Gorriz et al., 2020). Crop yield, however, is not a comprehensive indicator of farm economic benefits, as operational costs, investment costs, market price and subsidies also have a significant influence on farm profitability (Jezeer et al., 2018, 2017; Sgroi et al., 2015). Therefore, long-term profitability metrics that consider all the costs and income generated during the project lifetime such as, Net Present Value (NPV), Internal Rate on Return (IRR) and Discounted Payback Time (DPBT) are more appropriate economic metrics. For example in Italian lemon orchards, organic management resulted in lower yields than conventional management, but still provided higher NPV because of lower management costs and higher market price (Testa et al., 2015). Similar results were found for Italian olive orchards (Sgroi et al., 2015) and for coffee and cocoa (Jezeer et al., 2017). These are examples of organic and tropical agroforestry management, and to our knowledge there is no research that assesses the economic performance of agroecological management in Mediterranean woody crops. Yet, there is another reason why long-term consideration is needed for financial assessments. Economic settings are not static as market prices and costs of, e.g., labor and materials fluctuate. Therefore, it is important to incorporate these annual fluctuations in costs and revenues in order to project whether years with negative financial metrics are expected to occur more regularly. The production of agricultural commodities often results in environmental externalities that are not integrated in the market process (Bommarco et al., 2013). In the Mediterranean woody crop sector, decrease in soil organic carbon content and accelerated erosion rates are considered externalities with the strongest effect on land degradation (Montanaro et al., 2017). The magnitude of the externalities is management specific; as mentioned before, conventional tillage management results in higher erosion rates and lower soil organic carbon content than agroecological management (Cucci et al., 2016; Durán Zuazo