The effects of repeatedly cultivating under-sown cover crops (CC) on nitrogen (N) leaching were investigated in a long-term field experiment in SW Sweden (1989-2023). Treatments with and without CC and with and without N fertilization were compared (CC_90N, 90N, CC_0N, and 0N). The impact of temperature, precipitation and the large-scale North Atlantic Oscillation index (NAOi) was also explored. N leaching was measured in separately tile-drained field plots in which also the yield of the main crop, biomass and N content of the cover crop, and soil nitrate were determined. The mean annual N concentration in drainage and the annual N leaching were significantly smaller in CC_90N than in 90N in 18 out of 34 years. A trend analysis showed that N concentrations in drainage increased significantly after 2010 in both treatments without CCs but not in those with CCs. The reduction in N leaching by growing CCs averaged 48 % (CC_90N) over the period and did not decrease over time. NAOi correlated with temperature and precipitation and showed a positive trend after 2010. NAOi was positively correlated with N leaching in 90N but not in CC_90N. Furthermore, NAOi was positively correlated with N content in CC biomass. Our results suggest that on-going climate change in Scandinavia and periods of high NAOi result in higher N mineralization and higher N leaching. The study also shows that under these circumstances, growing an under-sown ryegrass cover crop is an effective measure for environmental protection since its N uptake compensates for higher N mineralization.

The recommendations presented in this policy brief are addressed to policymakers and relevant public authorities, including the Swedish Board of Agriculture, the Swedish Environmental Protection Agency, and the Swedish Energy Agency. The brief is also intended to inform companies, advisors, and other stakeholders in the agricultural and biogas sectors.

Hydrothermal carbonization (HTC) is a suitable treatment to valourize the organic matter and nutrient content of organic waste. However, the characteristics of the resulting hydrochars and their potential to act as organic fertilizers and soil amendments depend on nutrient transformations during HTC. Hydrochars were produced at 210 °C from five different feedstocks (pulp bio-sludge, digested and undigested sewage sludge, food digestate and cattle manure) and characterized. Hydrochars showed lower hydrogen-to-carbon and oxygen-to-carbon ratios than their respective feedstocks. Total nitrogen content decreased after HTC, with associated reductions ranging between 44 % and 67 % for manure-based and sewage sludge hydrochars, respectively. In a 120-day soil incubation with feedstock and hydrochar treatments, carbon dioxide (CO2-C) emissions, net nitrogen mineralization and water-extractable phosphorus (WEP) were monitored. Hydrochars were applied to soil either alone or in combination with NH4NO3 fertilizer. Hydrochars led to reduced CO2-C emissions compared with the feedstocks, while the addition of mineral nitrogen did not systematically affect cumulative CO2-C emissions from hydrochar-treated soils. Net N mineralization of the materials decreased in the order feedstock > hydrochar > hydrochar + mineral N. Tested hydrochars did not negatively affect radish seed germination, but plant growth decreased during the first three weeks of a pot trial, indicating N limitation in sewage sludge- and manure-based hydrochar treatments. Hydrochars may therefore serve as suitable amendments where C retention and soil conditioning are prioritized but may be less effective as short-term N and P sources than the raw feedstocks.

Crop models are useful tools for predicting changes in yield and nitrogen losses in response to changes in agricultural management practices and climate. We used a soil-crop model (CoupModel) to interpret trends in yields, drainage, and nitrate leaching observed for two contrasting treatments (fertilized and unfertilized cereals) in a long-term field experiment (35 years) on a sandy loam in southern Sweden. The model was calibrated using a Monte Carlo-based method, in which the 30 best simulations of 10,000 model runs were identified based on multiple criteria. The posterior distributions differed significantly between the two treatments for 6 of the 16 parameters included. For example, the decomposition rate coefficient of the slow organic matter pool was significantly larger in the unfertilized treatment. The model simulated yearly drainage and nitrate leaching well overall, but did not fully capture between-year variations. Although the simulated mean annual nitrate leaching was 1.4 times greater in the fertilized treatment, N leached per unit of N harvest was twice as large in the unfertilized plot. The model simulated substantial decreases in yield for both treatments in 2018 in response to an extremely hot and dry summer, although not as large as that observed. The range in simulated annual N mineralization due to parameter uncertainty was wider in the fertilized treatment. We conclude that model calibration strategies require careful attention to how different management practices may influence decomposition and long-term N balance components in agroecosystems and that more data on especially belowground biomass would help in reducing uncertainties.

This study investigated the effect of two different autumn tillage intensities, and a permanent green fallow, on subsurface nutrient leaching losses during nine years, with the overall aim to evaluate strategies for reduced nutrient load from arable land. The main hypotheses were that crop production results in larger leaching losses of nitrogen (N), phosphorus (P) and potassium (K) than a green fallow, and that reduced tillage (RT) is a measure for reduced N leaching without reduction of grain yields compared to conventional tillage (CT). The field site was a clay soil (47 % clay, Uderic Haploboroll) in south-west Sweden and the field experiment was equipped with separately tile-drained plots to record the subsurface drainage water flow. The water was analyzed for total N, nitrate-N, total P, phosphate-P and K. Grain yields of main crops and contents of soil mineral N were also determined. Long-term average and most annual means show no significant impact of tillage system, concerning N, P and K leaching losses or yields of main crops. There were indications of higher N leaching using CT compared to RT. Average leaching losses were 3.9 kg N ha-1 yr-1, 0.4 kg P ha-1 yr-1 and 6.5 kg K ha-1 yr-1 from the tilled plots. In 9-year average, the permanent green fallow reduced the soil mineral N content in autumn and decreased the transport of nitrate-N in drainage water compared to both tillage systems. However, green fallow could not be considered a mitigation option for P and K leaching losses.

Nordic agriculture faces big challenges to reduce phosphorus (P) loss from land to water for improving surface water quality. While understanding the processes controlling P loss and seeking for P mitigation measures, Norwegian and Swedish researchers have substantially benefited from and been inspired by Dr. Andrew Sharpley's career-long, high-standard P research. Here, we demonstrate how Sharpley and his research have helped the Nordic researchers to understand the role of cover crops in cold environmental conditions, best manure P management practices, and ditch processes. His work on critical source area (CSA) identification and site assessment tool development have also greatly inspired our thinking on the targeting of mitigation measures and the contextualizing tools for Nordic climate, landscape, and soils. While reflecting on Sharpley's legacy, we identify several needs for Norwegian and Swedish P research and management. These include (1) tackling the challenges caused by local/regional unevenness in livestock density and related manure management and farm P surpluses, (2) identifying CSAs of P loss with high erosion risk and high P surplus, (3) obtaining more high-resolution mapping of soils with low P sorption capacity both in the topsoil and subsoil, (4) improving cross-scale understanding of processes and mitigation measures and proper follow-up of applied mitigation measures, and (5) increasing collaborations of researchers with farmers and farmers' advisory groups and watershed groups by developing high-quality educational courses and extension materials. The needs should be addressed in the context of the challenges and opportunities created by climate change.

Adequate treatment of organic manures and digestates from livestock production should reduce environmental impacts and provide well-defined and attractive biofertlisers for a crop production market, which can promote the closure of the nutrient cycle in agriculture. In this sense, a survey was conducted during the autumn of 2021 to investigate Swedish farmers' perspectives on organic fertilisers use. The survey consisted of an online questionnaire, which was distributed broadly in the social media, homepages, different types of networks and at course events in order to reach all types of farms. There were 22 questions focused on current use, reasons for current use and preferences for future use. The analysis of the 99 fully responded surveys, demonstrated that 43% of the respondents think that they will increase their use of organic fertilisers in the coming 5-10 years and 60% think that they will use manure digestate in different forms (both solid and liquid fractions). Soil improvement was the main reason to use organic fertilisers, but there were also preferences for organic fertilisers with fast release of nutrients. The risk of soil compaction was the main reason not to use organic fertilisers and based on the responses, pellets and granulates seem to be more interesting than liquids and solids in general. Animal manures dominate the current use of organic fertilisers in Sweden however, other types of organic waste such as digestate and digestate derived fertilisers seems appealing to Swedish farmers. In conclusion, from this survey with 62% of the respondees in crop production, we found several indications of that there is a potential for increased use of organic fertilisers in Sweden on farms with limited use today. We found an openness, a broad interest and a demand for different types of products of different forms and origin. Since this demand in the end will almost always depend on the price of products in relation to the price of mineral fertilisers, which are fluctuating, we see the need of policy incentives in order to stimulate initiatives for the development towards increased circularity of nutrients.

CONTEXT: Agriculture plays a central role as a feedstock provider for the bioeconomy. However, utilization competing with food production and associated land use change have previously been a matter of debate. Nonetheless, strengthening the productivity of agroecosystems through sustainable intensification can prevent the depletion of natural resources, enhance food security, and facilitate adaptation to and mitigation of climate change. OBJECTIVE: This study explores the effects of combining crop residue removal for use as biomass feedstock with the establishment of intermediate crops to compensate for organic carbon depletion in arable land in Sweden. METHODS: The analysis relied on Swedish national agricultural statistics at the highest available spatial resolution (yield survey district). Crop residue calculations factored in crop:residue ratios, and harvestable and recoverable potentials. A model was devised to estimate land availability for cultivating intermediate crops based on generalized crop rotation sequences, and a spatial interpolation was employed to determine oilseed radish yields as a model intermediate crop. Estimates of long-term soil carbon inputs hinged on biomass carbon content and humification coefficients dependent on soil clay content. RESULTS AND CONCLUSION: The total annual residual biomass availability in the country stands at approximately 2139 kt per year. The potential harvestable biomass production from intermediate crops was estimated at 383 kt per year. However, spatial differences were evident in total biomass production and effects on soil organic carbon inputs. For the majority of districts, the inclusion of intermediate crops could offset the negative effect of a complete removal of crop residues on soil organic carbon inputs. In other cases, establishing intermediate crops could not compensate for these negative effects, but some differences were observed when comparing the harvesting and the incorporation of the intermediate crops' biomass. Spatial disparities originated from variations in soil texture, intermediate crop yield, and rotation sequences. SIGNIFICANCE: This research is an attempt to address the challenge of maintaining and increasing the soil carbon stocks under the context of a growing biomass demand in a developing biobased economy. It highlights the divergent effects of combining crop residue removal with the inclusion of intermediate crops under distinct agroecological conditions in the Northern European context. By giving estimates on biomass availability and effects on soil organic carbon inputs, we provide information that can support decision making for bioeconomy planning and sustainable resource utilization. This also has long-term implications for preservation of soil fertility, agricultural productivity and climate change mitigation.

A field experiment with separately tile-drained plots was established on a sandy loam soil in 1993 to investigate management practices that can reduce nutrient leaching. Practices tested included timing of tillage in autumn or spring (ploughing with or without preceding cultivation) and catch crops in systems with mineral fertilizer alone or in combination with pig manure. Drainage water from each plot was collected separately and analyzed for total nitrogen (tot-N), nitrate-N (NO3-N), total phosphorus (tot-P), phosphate-P (PO4-P), and potassium (K). Biomass of catch crops, soil mineral N content, and yield of the main crop were also determined. The experimental set-up was modified after 14 years, but the core research questions were the same and the results from the two periods (1993–2006, 2007–2021) were comparable. Spring tillage and undersown catch crops (perennial ryegrass, Lolium perenne L.) reduced tot-N leaching and concentrations in drainage water compared with autumn tillage. However, a combination of spring tillage and catch crop increased tot-P leaching and concentrations in drainage water compared with autumn tillage and no catch crop. Use of pig manure increased tot-N leaching and concentrations in drainage water compared with treatments without pig manure, both with and without a catch crop. Treatments without a catch crop showed substantial growth of biomass during autumn in terms of weeds and volunteer plants, but growing a catch crop resulted in more biomass in most years. A catch crop was more effective in reducing N leaching than only weeds and volunteer plants, probably mainly due to its ability to survive winter and take up and store N over a longer period. Leaching of K increased with a catch crop, while the other treatments did not influence K losses. Yield of main crops was not affected by the different treatments.

Eutrophication assessments in water management to quantify nutrient loads and identify mitigating measures seldom include the contribution from horse facilities. This may be due to lack of appropriate methods, limited resources, or the belief that the impact from horses is insignificant. However, the recreational horse sector is growing, predominantly in multi-functional peri-urban landscapes. We applied an ecosystem management approach to quantify nutrient loads from horse facilities in the Stockholm Region, Sweden. We found that horses increased the total loads with 30–40% P and 20–45% N, with average area-specific loads of 1.2 kg P and 7.6 kg N ha −1 year −1 . Identified local risk factors included manure management practices, trampling severity, soil condition and closeness to water. Comparisons of assessment methods showed that literature standard values of area-specific loads and water runoff may be sufficient at the catchment level, but in small and more complex catchments, measurements and local knowledge are needed.

The European Commission has set targets for a reduction in nutrient losses by at least 50% and a reduction in fertiliser use by at least 20% by 2030 while ensuring no deterioration in soil fertility. Within the mandate of the European Joint Programme EJP Soil 'Towards climate-smart sustainable management of agricultural soils', the objective of this study was to assess current fertilisation practices across Europe and discuss the potential for harmonisation of fertilisation methodologies as a strategy to reduce nutrient loss and overall fertiliser use. A stocktake study of current methods of delivering fertilisation advice took place across 23 European countries. The stocktake was in the form of a questionnaire, comprising 46 questions. Information was gathered on a large range of factors, including soil analysis methods, along with soil, crop and climatic factors taken into consideration within fertilisation calculations. The questionnaire was completed by experts, who are involved in compiling fertilisation recommendations within their country. Substantial differences exist in the content, format and delivery of fertilisation guidelines across Europe. The barriers, constraints and potential benefits of a harmonised approach to fertilisation across Europe are discussed. The general consensus from all participating countries was that harmonisation of fertilisation guidelines should be increased, but it was unclear in what format this could be achieved. Shared learning in the delivery and format of fertilisation guidelines and mechanisms to adhere to environmental legislation were viewed as being beneficial. However, it would be very difficult, if not impossible, to harmonise all soil test data and fertilisation methodologies at EU level due to diverse soil types and agro-ecosystem influences. Nevertheless, increased future collaboration, especially between neighbouring countries within the same environmental zone, was seen as potentially very beneficial. This study is unique in providing current detail on fertilisation practices across European countries in a side-by-side comparison. The gathered data can provide a baseline for the development of scientifically based EU policy targets for nutrient loss and soil fertility evaluation.

Phosphorus (P) losses from clay soils can be mitigated by introducing measures for improving soil structure. These include structure liming, where a mixture of CaO or Ca(OH)(2) and CaCO3 is added to the soil. In a field experiment with separately tile-drained plots on a clay loam in Sweden, we examined the effects of structure liming on leaching of total-P, phosphate P (PO4-P) and total nitrogen (N) during three years after initial application. The treatments included two application rates (8 and 16 t ha(-1)) of a common product in comparison with a control (no lime). Effects of structure liming emerged during the second and third year after application, with 45 and 38% lower total-P leaching than in the unlimed control. A significant effect of the application rate was found in the third year. Nitrogen leaching and crop yield were not affected. As expected, soil pH raised following structure lime addition. Measurements of aggregate stability did not confirm the reduction in P leaching, indicating that it is important to measure P concentrations in drainage water directly when assessing the effect of structure liming.

ABSTRACT In this five-month Swedish field study, we examined losses of nutrients from horse manure over time, in order to examine how regularly manure should be cleared from paddocks in order to minimise the risk of nutrient leaching. Small heaps of manure (400 g) were placed in open cylinders outdoors and samples (five replicates) were taken on 12 occasions from December 2020 to May 2021. The samples were analysed for weight, dry matter content and concentrations of total nitrogen (N), ammonium N, total phosphorus (P), water-extractable P (WEP), potassium (K) and carbon (C). There was a fast decline in P and K concentrations and a strong correlation between accumulated precipitation and losses from the manure into the soil. The mean reduction in total-P was 11 mg P kg−1 manure dry weight per mm accumulated precipitation. Manure N was retained in the manure over the five-month period. In conclusion, this study demonstrated high mobility of P and K, indicating a need for strategies for rapid removal of manure from paddocks. Daily removal of manure from paddocks used year-round would, approximately, save 1.7 kg P and 5.5 kg K per horse per year, which could be recycled to replace non-renewable mineral fertilisers.

A stocktake study took place across 23 European countries to formulate recommendations for harmonising methodologies for delivering fertilisation guidelines. The stocktake revealed substantial differences in the content, format and delivery of current fertilisation guidelines across Europe. Substantial differences exist in soil test methods and how crop nutrient requirements are calculated; even between neighbouring countries, with similar soil types, cropping systems and within the same environmental zone. The general consensus from all participating countries was that harmonisation of fertilisation guidelines should be increased, in terms of shared learning in the delivery and format of fertilisation guidelines and mechanisms to adhere to environmental legislation. Some recent publications have assessed conversion equations that would enable data sets derived by different methods to be combined, but much research is still required. It was recognised in this study that it would be very difficult, if not impossible, to harmonise soil test data and agronomic requirements at EU-level due to soil types and agro-ecosystem influences. Nevertheless, increased future collaboration especially between neighbouring countries within the same environmental zone was seen as potentially very beneficial, and would contribute to the European Green Deal Vision. National guidelines for fertilisation planning and awareness of farm-gate N and P balances could help farmers optimise nutrient use, improve farm efficiencies and provide an overview of potential environmental risks on their farms. Additionally, advancement of precision agriculture technology, enabling greatly increased nutrient use efficiency at farm and field level through site-specific and precise fertiliser placement, and improved rate and timing of nutrient application, would be beneficial. Harmonisation or standardisation should not be an end in itself, but the main goal should be to increase nutrient use efficiency and minimise environmental impact.

Faltstudien utfordes pa Hushallningssallskapets forsoksgard Lilla Boslid i Halland. I forsoket studerades strukturkalkning med 8 och 16 ton/ha av fuktig blandprodukt (Fostop, Nordkalk), i jamforelse med okalkad mark (kontroll) pa ett forsoksfalt med specialdranerade rutor. Draneringsvattnet fran varje enskild ruta leddes via ett draneringsror till matstationen dar vattenflodet mattes kontinuerligt och koncentrationen av totalfosfor, fosfatfosfor, totalkvave och turbiditet i det avrinnande vattnet analyserades. Forsoket kalkades i september 2018 och utlakningsmatningarna paborjades sa fort avrinningen kom igang och pagick sedan over tva vintrar fram till och med januari 2021. Jordarten pa forsoksfaltet ar en mellanlera med i genomsnitt 29% lerhalt (26-33) i matjorden (0-30 cm) och nagot hogre i alven. I ovrigt dominerar kornstorlekarna mo och mjala. Lerfraktionerna bestar till storsta delen av svallande mineral. Jordprover for test av aggregatstabiliteten togs pa varen 2019 och 2020 da jord fran det oversta lagret sallades for att fa fram jord i aggregatklassen 2-5 mm. Dessa aggregat utsattes sedan for regn i en regnsimulator och det avrunna vattnet analyserades for elektrisk konduktivitet och turbiditet. I samband med uttaget av jordprover till aggregatstabilitet togs aven matjordsprover (0-20 cm) ut for analys av pH, Ca-AL och elektrisk konduktivitet. Faltforsoket har inte pavisat nagra statistiska skillnader mellan kontrolledet utan kalk och de tva leden med 8 respektive 16 ton kalkgiva/ha, avseende utlakning av totalfosfor, fosfatfosfor, kvave och turbiditet i draneringsvattnet. Andra aret uppvisade dock en tydlig tendens till minskad utlakning av totalfosfor (40%) och turbiditet med strukturkalkning. Andra arets tendens till minskad utlakning av totalfosfor visar ocksa att skillnaden mellan kalkgivorna 8 och 16 ton/ha var sma vilket tyder pa att en storre mangd kalkblandning inte ger en storre effekt pa utlakningen fran den har jorden. Under det tredje arets borjan planade dock tendensen ut och inga skillnader mellan leden kunde ses. Ytjordens struktur, i form av aggregatstabilitet matt som turbiditet och EC i draneringsvattnet fran jordprover som utsatts for simulerat regn, forandrades inte till foljd av strukturkalkningen. Matjordens pH var hogre i de kalkade leden jamfort med kontrolledet bada aren medan EC och Ca-AL hade statistiskt hogre varden andra aret och en tendens till hogre varden forsta aret. Skorden av varkorn tenderade att bli hogre med okad kalkgiva men karnans innehall av P och N paverkades inte av kalkningen. Matningarna av utlakningen skulle behova foljas upp under flera ar framover, for att kunna se om strukturkalkningen far effekt pa langre sikt eller ger effekt framst under forhallanden med stor partikeltransport, eller om effekten ar fordrojd genom langsammare reaktioner mellan kalk och ler an vantat.

This study investigated phosphorus (P) retention materials of sand and limestone outside houses in paddocks for organic laying hens, as a measure to retain P and reduce leaching. When manure P, accumulated in the materials during 6 months, was exposed to rain simulations in a lysimeter study, P concentrations in drainage water were high from all treatments (58-136 and 130-197 mg L-1 of PO4-P and total-P respectively). On average, 14% of the manure P, captured in the materials was leached after 100 mm of simulated rainfall. The conclusion is that these materials may efficiently retain P during the outdoor season (May to October), but in order to reduce the risk of losses to waters during the following winter they need to be removed from the paddocks, preferably to arable fields. The materials can be regarded as potential P fertilizers and may thereby combine increased P use efficiency and environmental performance of organic outdoor poultry systems.

Separation of slurries can facilitate the nutrient management on farms through nutrient partitioning between the liquid and the solid fraction. The distribution of nutrients in the slurry fractions depends largely on the type of separator used. The current study assessed the separation efficiency of a two-step separation treatment of pig slurry including in-series a screw press and a centrifuge followed by acidification (to pH 5.9) of the final liquid effluent. The system concentrated 73.8% of the slurry's Phosphorus (P) content, 52.6% of Total solids (TS) and 14.4% of total Nitrogen to the solid fraction. The apparent N recovery from ryegrass fertilized with the raw slurry and non-acidified liquid fractions was not decreased by the separation treatment. The acidified liquid fraction showed 28% and 9% higher apparent N recovery compared to the raw slurry and the non-acidified liquid effluent from the centrifuge respectively. The biochemical methane production potential (Bo) of the acidified liquid fraction was reduced by 50% and 25%, compared to the non-acidified counterpart and the raw slurry, respectively. The results highlight the potential of a double separation system coupled with acidification of the liquid fraction, to extract P into a solid fraction which can be transported outside the farm, and to increase N utilization from the liquid fraction when this is used as organic fertiliser on or nearby the farm. The study further highlights the potential to reduce CH4 emissions from slurry storage after mechanical separation and acidification of the liquid slurry fraction.

This study investigated manure loads in outdoor paddocks for laying hens and the capacity of two phosphorus (P) retaining materials for reducing leaching from manure in areas with high hen density. Inventories on two commercial farms during 2 years (2017 and 2018) of the impact of hens (groups of 3000 hens) on vegetation, as a proxy for land use by hens, showed that 16–21% of outdoor area in grassland paddocks and 22–39% of area in a forest paddock were used by the hens. Sand and limestone were tested as P retention materials in areas with high manure load in a field study during the outdoor season for laying hens (May 1 to October 31 in 2018). The materials were placed on the ground (0.2 m deep bed, 3.3 m wide) outside the pop-hole in paddocks with 76 hens. The average numbers of hens outdoors were recorded at 9 am and 3 pm daily. There was no significant difference between the materials concerning distribution of hens, and they seemed not to prefer any material more than the other. When cylinders containing the spent materials were exposed to simulated rainfalls in a laboratory study, the P concentrations in drainage water were high for all materials, including a control with gravel (58–136 mg PO 4 -P L −1 and 130–197 mg total-P L −1 ). On average, 14% of manure P retained in the sand and limestone materials was leached after 100 mm of simulated rainfall. Thus, these materials may act as physical filters for P in manure, but to reduce the risk of P losses to waters during the following winter, they need to be removed from the paddocks and preferably used as potential P fertilizers on arable land.

A field experiment with separately tile‐drained plots was used to study the ability of oilseed radish ( Rhaphanus sativus L.), as a cover crop sown after harvest of a main crop of cereals or peas, to reduce nitrogen (N) and phosphorus (P) leaching losses from a clay loam in southern Sweden over 6 years. In addition to oilseed radish in pure stand, two cover crop mixtures (hairy vetch ( Vicia villosa ) and rye ( Secale cereale ) for 3 years and oilseed radish in mixture with buckwheat ( Fagopyrum esculentum) for 2 years) were tested. The cover crop plots (three replicates per treatment) were compared with unplanted plots as a control. Plots cropped with oilseed radish during autumn (August–November) had significantly smaller yearly mean N concentration in drainage water over 5 of 6 years compared with unplanted controls. Mineral N content in the soil profile in autumn was significantly less in oilseed radish plots than for control plots in all years. The cover crop mixtures of hairy vetch and rye or buckwheat and oilseed radish also showed the potential to reduce soil mineral N in autumn and N concentration in drainage water, compared with unplanted controls. The cover crops had no impact on P leaching. In conclusion, oilseed radish has the ability to reduce leaching losses of N, without increasing the risk of P leaching.