LuWQ2021 is an interdisciplinary conference on the cutting edge of science, management and policy to minimise effects of agriculture and land use changes on the quality of groundwater and surface waters. The conference aims to discuss the entire ’policy cycle’ to enable enhancing the quality of the water environment, which includes problem recognition, formulation of technical options, policy formulation, interaction between policy makers and stakeholders (i.e. pressure groups), policy implementation, monitoring and research. The conference also aims to facilitate networking opportunities and to intensify contacts (a) between soil/water related scientists, agro-related scientists, social scientists, ecological scientists and economists, and (b) between scientists, water managers and policy makers. The key strength of the conference is twofold. On the one side, LuWQ has a well-defined narrow focus on ‘agriculture and water quality’. On the other side, the conference is broadly oriented with regard to the various professional disciplines related to the conference topics. Based on the experience from previous Land Use and Water Quality conferences, it is just the diversity in professional background of participants which results in a multi-faceted conference programme. Consequently, LUWQ offers sessions on a broad variety of topics, all of them however dedicated exclusively to agriculture and water quality. In this sense, the conference topics range – to illustrate by a few randomly chosen examples – from scientific research on denitrification and travel time, …, challenges in monitoring and modelling at different scale (parcels, field, region), …, practice-oriented and technical measures to limit leaching of nutrients and agrochemicals, …, development of management options to mitigate effects on water quality in drinking-water protection areas, including cooperation between local governments, water supply companies and farmers, …, to policy development, and lessons to be learned from policy implementation, e.g. comparison of farmers’ behaviour between top-down and bottom-up implementation of agri-environmental measures.