This practice abstract presents a summary of the WOCAT documentation of existing NSWRM in the OPTAIN case studies: https://qcat.wocat.net/en/wocat/technologies/view/technologies_6250/Sub… is carried out on arable land and involves pulling a subsoiler behind a tractor, wherein chisels (tines) effectively break up compacted layers beneath the soil surface. It disrupts the dense layer and promotes soil loosening. As a result, subsoiling enhances the air-water relations within the soil, leading to an overall improvement in soil quality. The depth of subsoiling can be adjusted. Deeper subsoiling may be required on heavier soils.Subsoiling is particularly beneficial for root crops such as sugar beet, while its use for other crops will vary depending on individual soil conditions and needs. The spacing between chisels and the power of the tractor can be customized. However, an average spacing between the chisels is 50 cm, and a tractor with a horsepower of 200 is able to pull a five-tine subsoiler.Subsoiling is a time-consuming process, with an average rate of about 10 hectares per day. It is necessary every year during sugar beet planting. In other fields, annual subsoiling is only recommended to the machinery tracks and headlands where the machine turns. Subsoiling is often done after harvest and before subsequent field operations such as ploughing.Considering crop rotation practices, the entire field is typically subsoiled only once every four years on average. This approach makes subsoiling a viable alternative to traditional ploughing, as it loosens the soil without turning it. Consequently, subsoiling can be integrated into reduced tillage systems, contributing to sustainable agricultural practices.

This practice abstract presents a summary of the WOCAT documentation of existing NSWRM in the OPTAIN case studies: https://qcat.wocat.net/en/wocat/technologies/view/technologies_6203/Buf… strips and hedges consist of natural vegetation such as grass, bushes, and trees. They are strategically placed along the edges of fields, roads, and surface water bodies. Their primary function is to serve as permanent natural buffers that intercept and reduce the transport of nutrients and sediments from agricultural fields. By slowing down surface runoff and promoting infiltration, they help mitigate the negative impacts of runoff. There are also ecological benefits to the establishment of these green corridors.Field margins, headlands, and strips left between fields naturally facilitate the germination and growth of vegetation. Alternatively, buffer strips and hedges can be intentionally established following a planting plan that specifies the species, their locations, and dimensions.Hedgerows also have drawbacks for farmers and landowners. They take up cropland, which initially reduces yields and they cannot be easily removed, limiting management flexibility. In Hungary, where these buffer strips have been implemented, forestry legislation stipulates that a strip of trees wider than 20 meters and larger than 0.5 hectares in total area is considered a forest, imposing strict regulations accordingly.

OPTAIN documented a constructed wetland connected to tile drains that is designed to function in a natural manner. The objective is to enhance water quality, reduce runoff velocity, and support biodiversity. It combines the functions of retaining and gradually releasing water, while also remediating (i.e., cleaning) drainage waters, with a particular focus on reducing pollutants such as nitrates and pesticides. The wetland is established either in connection with or directly on tile drains and is designed to facilitate both subsurface and surface flow. The substrate used in its construction consists of a mixture of 6-month matured birch chips (4-30 mm in length) and gravel (4–8 mm in diameter) in a 1:10 ratio. The wetland is then planted with reed canary grass (Phalaris arundinacea) and reed manna grass (Glyceria maxima). The wetland to catchment ratio (WCR) ranges between 2:1000 and 3:1000, which means that, for example, a constructed wetland of 200 m2 or 300 m2 would be needed to serve an area of 10 ha.The process of establishing such a wetland begins with identifying the locations where this measure is necessary. The drainage system must be accurately mapped, and an appropriate site for the wetland must be selected. Subsequently, the wetland is designed and planned, taking into account the associated costs, labor requirements, and the amount of land that will be taken out of production. Administrative tasks involve processing statements and obtaining permission from state offices and landowners.

This practice abstract presents a summary of the WOCAT documentation of existing NSWRM in the OPTAIN case studies: https://qcat.wocat.net/en/wocat/technologies/view/technologies_1245/Red… tillage, specifically avoiding tillage in autumn, is an effective measure to prevent soil erosion, particle loss, and nutrient runoff from cropland into watercourses. Apart from protecting soil against water erosion, stubble fields contribute to increased organic matter content, potentially enhancing soil aggregate stability in the upper layers. This measure may also promote higher biological activity, leading to improved soil structure.Implementing no tillage in autumn involves leaving cropland areas as stubble fields after harvest and maintaining this state throughout the winter. It is important to consider the potential for increased weed growth and diseases, including fungi, when adopting this practice. Additionally, in humid climates, the soil may develop a compacted structure over time. 

This practice abstract presents a summary of the WOCAT documentation of existing NSWRM in the OPTAIN case studies: https://qcat.wocat.net/en/wocat/technologies/view/technologies_6169/Gra… waterways are shallow channels (natural or constructed) with grass cover that are effective in carrying surface water down slopes without causing soil erosion. They utilize vegetation to disrupt water flow and protect soil from erosion. In agricultural areas, they manage concentrated flow by redirecting runoff over grassed areas rather than over bare, erodible soil. Grass roots bind the soil, reducing runoff velocity and erosion, while enhancing infiltration and filtering runoff.Grassed waterways are typically positioned in erosion-prone areas downslope of agricultural fields and are combined with inlets to direct runoff into drainage pipes. An alternative approach is to leave natural waterways covered with stubble over the winter, which reduces erosion but is less effective and doesn't have the same nutrient uptake benefits as grass cover. The efficiency and impact of vegetation zones depend on flow properties, such as velocity, water volume, sediment concentration, as well as precipitation characteristics.

This practice abstract presents a summary of the WOCAT documentation of existing NSWRM in the OPTAIN case studies: https://qcat.wocat.net/en/wocat/technologies/view/technologies_6266/Hed… are linearly structured shrub communities established along the contour lines of sloping land to subdivide large fields, reduce soil erosion, and create valuable semi-natural habitats. Hedgerows intercept rainwater and slow down surface runoff from adjacent fields. Improved soil structure and deeper root systems in the hedgerow area increase infiltration rates and allow particles to settle. Both of these factors reduce water erosion and nutrient leaching. On steep slopes or embankments, deep roots can prevent wet soils from slipping. Additionally, the hedge as a landscape structure reduces the wind speed and wind erosion.An effective hedge must be properly placed and established. The optimal hedge is a multi-row hedgerow with a herbaceous border on both sides. The width of the hedge should be 5-6 m. Planting is usually done in October-November and a newly planted hedge requires regular watering (100 liters for trees, 20 liters for shrubs), which is one of the highest costs of a hedge. Maintenance pruning can be divided into pruning for putting the hedges on stock (every 10-15 years) and pruning for shape and maintenance (every year). A hedge should be divided into at least three sections, which should be put on stock in succession. In this way, the hedge always retains a flowering and a fruiting aspect.Potential drawbacks for farmers and landowners are that hedges take up cropland and they cannot be easily removed, limiting management flexibility. Furthermore, in Germany, a specific set of species is required to qualify for financial support

What can we do together to advance the adoption of Natural/Small Water Retention Measures (NSWRMs) in Europe? Experts, decision-makers, and academics from the 14 OPTAIN (https://www.optain.eu/) case studies across Europe's Continental, Pannonian, and Boreal biogeographical regions proposed solutions in legislation and governance arrangements, improved use of tools and techniques for water and nutrient management, and better defined economic sustainability of technologies. In addition, they pointed out gaps and possible solutions in implementing and promoting NSWRMs. The suggestions were gathered in five Key Messages for improved implementation of NSWRM:1. Increased use of cross-referencing in the directives and strategy documents is needed for improved coherence on national and local levels.2. Intersectoral arenas must be established on the different administrative governance levels for harmonized agro-environmental policy programmes.3. Advancing financial schemes for higher integration of water and agricultural policy in practice demands multipurpose interventions with an acceptable cost-benefit ratio and special consideration of specific land ownership, farm size, and landscape characteristics.4. Improved administration competencies, simplified procedures, and increased data availability must be accomplished to better support end-users in integrating water and agricultural policy in practice.5. Awareness and knowledge are essential for municipalities, local communities, water managers, and farmers to be able to adopt new measures and approaches for water and nutrient retention.Read more in the OPTAIN Policy Brief: https://www.optain.eu/deliverables#policy