Vincent de Leijster

10 Chapter 1 approaches include conservation agriculture (Knowler & Bradshaw, 2007), agroecology (Altieri, 2002), ecological intensification (Bommarco et al., 2013; Tittonell, 2014), and regenerative agriculture (La Canne & Lundgren, 2018). Each of these approaches aims at improving and maintaining ecological functionality and is closely related regarding the type of agricultural management practices it promotes. For example, ecological intensification, which is the youngest term, is defined by González de Molina and Guzmán Casado (2017) as “the intensification in the use of the natural functionalities that ecosystems offer for the maximization of primary production per unit area without compromising the ability of the system to sustain its productive capacity”. Conservation agriculture aims to minimize disturbances to the soil to conserve natural resources (Hobbs et al., 2008), and agroecology aims to improve internal ecological processes and services in the food system (Aguilera et al., 2020). In addition to being a scientific discipline, agroecology is also a social movement, which is the most striking difference with ecological intensification (Tittonell, 2014). In this dissertation I study agroecology as it is the oldest, and in my opinion, most comprehensive approach, and I focus on its principles related to land management. Agroecology is not based on a fixed set of land management practices, but rather promotes several concepts, such as minimizing soil disturbance, securing favorable soil conditions, diversifying species (including crops), recycling biomass, and minimizing the loss of resources (Altieri, 2002). In order to find the specific land management practices, adaptation to local biophysical and cultural conditions is required (FAO, 2018). Examples of land management practices that are applied according to agroecological principles; include permanent vegetation covers, application of soil amendments, no tillage, intercropping, and agroforestry (Rosa-Schleich et al., 2019). Agroforestry systems are productive land-use systems that combine woody perennials and agriculture or livestock in the same land unit, and thus they follow the agroecological concept of species diversification (Nair, 1993). The ecological impact of agroecological management is now being studied more frequently; for example, a recent meta-analysis on agroecological management in Mediterranean fruit crops demonstrated that the agroecological approaches of no tillage, organic soil amendments and intercropping each improved the soil organic carbon content, when compared to conventional management (Morugán-Coronado et al., 2020). Furthermore, agroforestry has been demonstrated to enhance biodiversity in Europe and in the tropics (De Beenhouwer et al., 2013; Torralba et al., 2016). Effectiveness of practices may differ between regions; for example, a global analysis showed that permanent vegetation cover improves soil water retention, but this effect is more pronounced in dry regions than in humid regions (Basche & DeLonge, 2017). Some practices may improve one outcome but negatively affect another, and this is referred to as a trade-off (Bennett et al., 2009).