Current challenges, methods, and strategies for reducing the transfer of nonpoint source pollution from agricultural areas to surface water

Agricultural diffuse pollution, also referred to as nonpoint source pollution, is widely recognised as one of the primary challenges to achieving good ecological status in surface waters. This paper synthesises current knowledge on strategies and technical approaches designed to reduce nutrient and contaminant transfers from agricultural landscapes to rivers, lakes, and reservoirs. A broad spectrum of mitigation measures is assessed, including riparian buffer zones, vegetated filter strips, grassed waterways, constructed wetlands, denitrifying bioreactors, permeable barriers, stormwater management on agricultural land, and Good Agricultural Practices. The effectiveness of these measures is examined in relation to biophysical, hydrological, and geomorphological conditions, as well as their ability to provide additional ecosystem services, such as biodiversity enhancement and flood mitigation. Particular emphasis is placed on emerging global challenges, including climate change, which alters precipitation patterns and increases the frequency of extreme weather events, and the growing presence of microplastics and nanoplastics. Persistent barriers to implementation are identified, including fragmented governance frameworks, economic constraints, slow ecological responses, and limited stakeholder engagement. Advances in remote sensing, and geographic information systems are highlighted as essential tools for identifying critical source areas, optimising land management strategies, and improving spatial planning at the catchment scale. A prevention-focused hierarchy of measures is proposed, supported by adaptive and integrated water resource management principles. This paper offers a comprehensive synthesis of scientific and practical insights intended to support policy development, guide effective environmental management strategies, and contribute to achieving Sustainable Development Goal 6 and related European Union water quality objectives.