| Summary: | Short-term fertility-building legume-grass leys are essential to organic farming as they provide the major nitrogen input into the system. Increasing the diversity of plant species within these leys can improve the stability of these mixtures for a range of environmental conditions. This thesis provides evidence that increased ley diversity can also provide additional benefits to pollination and decomposition services alongside fertility building. Compared to a farmers' standard ley, increased ley diversity provided a season-long forage resource for a range of pollinating insects, while also providing a stable environment for earthworm species. However, the scale of this benefit is dependent on management practice, with grazing negatively impacting on pollinator abundance. The preference of different pollinator groups for a range of legume species showed that the diverse mixture is able to offer a forage resource to a wider range of pollinator species with differing functional traits, than a simple legume monoculture. The mowing management of the ley significantly alters the benefit to pollinator species. A non-intensive management regime such as hay production provides the greatest forage resource. However, even under more intensive mowing regimes the diverse ley mixture provided a better forage resource than the farmers' standard ley. Diverse mixtures aiso benefit earthworm species, have a longer incorporation time by macrofauna after ploughing, and produced a wheat grain and forage with a greater protein content than the farmers' standard ley. The findings addressed in this thesis show that cross-disciplinary research can produce multiple ecosystem benefits from novel approaches to farm management. The study outlines recommendations to growers that benefit pollination and decomposition services, and highlights future research questions and opportunities.
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