Vincent de Leijster

79 Almond farm profitability under agroecological management 4 nor the restoration costs of off-site sedimentation. The erosion costs of Görlach et al. (2004), which we used in the current study, incorporated these additional costs. However, this study also has strong limitations as erosion costs were generalised for the entire European land surface and calculated per hectare without relating to quantity of lost soil. Therefore, more research is needed to estimate the costs of erosion per land use type and per quantity of lost soil. In another study, the erosion costs in Italian vineyards were estimated at €1,575 ha -1 y -1 (Galati et al., 2015), which is much higher than the values we report. This can be explained by the 10-fold erosion rates in the Italian study compared to our study, making the costs per ton lost soil comparable. Moreover, Galati et al. (2015) reported that agroecological management reduced erosion by 61% in Italian vineyards, which is comparable to what we found. Despite the significant reduction in erosion rates through implementing agroecological practices, long-term profitability did not improve when erosion costs were accounted for, as low levels of erosion persisted and still resulted in costs, consequently NT and GM were associated to lower NPV than CT (Table 4-4). 4.4.4 Recommendations Based on our findings we make recommendations on how to overcome barriers that hamper large scale adoption of agroecological management. First, we suggest that organic certification schemes should incorporate additional criteria on farm soil and vegetation management. By doing so, organically produced almonds will lead to lower negative environmental impact, which will provide a stronger contrast between the environmental performance of conventionally versus organically produced almonds. Secondly, we call for more research on a wider range of vegetation cover practices. More knowledge is needed on how ecological and economic performance can be optimized by either varying in the distribution of tilled soil versus vegetation covered soil (e.g. full cover, narrow vegetation strips, alternating alleys, etc.), or by combining vegetation covers with organic amendments. Finally, it is necessary to reconsider whether the value that is attributed by society to the environment of agroecological landscapes is high enough to sustain agricultural production in the future. In some regions more financial compensation, either through public investment or through private investment, is needed than is currently paid in order to match the observed opportunity costs of some types of agroecological management.