Vincent de Leijster

30 Chapter 3 ABSTRACT There is an increasing body of studies that show that land use intensification and homogenization in agriculture landscapes, aimed at increasing food provisioning, decline other ecosystem services. Agroecological management has been proposed as an alternative to conventional agricultural management because of its presumed capacity to rehabilitate degraded ecosystem services. In this study we tested whether the agroecological principles of minimum mechanical soil disturbance, maintaining understory cover and application of organic amendments can improve the provisioning of ecosystem services and whether bundles of ecosystem services emerged. We experimentally implemented no tillage (NT), green manure (GM), compost (CM) and conventional tillage (CT) as a control in five almond orchards in south-eastern Spain and monitored nutrient cycling, carbon stock, habitat provisioning, food provisioning, pest control and pollination after one year. We found that CM and NT had a higher overall ecosystem service performance than CT, and that GM did not differ from CT. The treatments significantly improved ecosystem services such as nutrient cycling, carbon stock, habitat provisioning and food provisioning, but not pest control and pollination. CM treatment resulted in higher soil enzyme activity (glucosidase and phosphatase), soil nutrient content (total N and extractable K), leaf nutrient content (P and K concentrations), soil organic carbon (SOC) content and almond kernel weight compared to other treatments. GM treatment resulted in higher phosphatase activity, understory carbon content and more understory cover than CT. NT treatment resulted in higher glucosidase, phosphatase and urease activity, understory plant diversity and more understory cover than CT. We also found an emerging bundle between SOC and soil enzyme activity and between individual almond weight and soil nutrient levels and SOC. This study shows that ecosystem services can rehabilitate rather quickly, given the one-year time frame of the study. Further, each agroecological practice may enhance a specific set of ecosystem services.