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Raportti kuvaa fosforin ja typen kierrätyksen nykytilanteen Suomessa ml. perustiedot biomassojen ja niiden sisältämien ravinteiden määristä sekä alueellisesta jakaumasta. Esitettyjen tietojen pohjalta annetaan toimenpide-ehdotuksia ravinteiden kierrätyksen edistämiseksi. Luonnonvara- ja ympäristötutkimuksen yhteenliittymä LYNET:iin kuuluvien laitosten asiantuntijoiden yhteistyönä toteutettu selvitys tehtiin taustaksi kansalliselle ravinteiden kierrätyksen toimintaohjelmalle.Raportissa ehdotetaan mm. ravinteiden käytön ohjauskeinojen kokonaisuudistusta, jossa luotaisiin yleinen kaikkea viljelyä ja lannoittamista koskeva säädös esim. nitraattiasetusta kehittämällä. Samalla luovuttaisiin ympäristökorvausjärjestelmän nykyisenkaltaisesta ravinteiden käytön ohjauksesta ja selkeytettäisiin eläinsuojan ympäristöluvan roolia ja suhdetta yleiseen normiohjaukseen. Ohjauksen tueksi luotaisiin peltolohkokohtainen ravinnetietokanta.

Vesistöjä kuormittavia ravinnepäästöjä tulee vähentää. Päästötpienenevät ravinteiden kestävällä käytöllä sekä eloperäisten sivuvirtojenravinteiden kierrätyksellä. Luonnonvara- ja ympäristöalan tutkijatehdottavat toimia ravinteiden kierrätyksen vauhdittamiseksi.

The Nordic countries have, during the last 20 years, introduced efficient measures to reduce nitrogen losses to the environment. Still, nitrogen losses from the agricultural sector are high. In this report we provide recommendations on strategies and policy instruments to achieve cost effective abatement of reactive nitrogen from agriculture in the Nordic countries.This report is based on a literature review. Additional input was also obtained from discussions at a workshop held in Gothenburg in January 2017. The workshop made it possible for experts from the four Nordic countries Denmark, Finland, Norway and Sweden to come together and discuss and compare policies and mitigation measures regarding nitrogen and agriculture. During the workshop we identified a number of policy challenges, policy actions and also knowledge gaps where further research is needed.

In the Finnish conditions, annual N leaching from the experimental plots was not adequately estimated using the respective annual N balances, or supplementing the estimation with annual precipitation, total runoff, or drainage runoff (Salo and Turtola, 2006). Values averaged over the years improved the estimation when management included such environmentally risky managements as bare fallow or off-season application of cow slurry (Salo and Turtola, 2006). Calculated with the linear regression (Salo and Turtola, 2006), N leaching was 20-57 % of the averaged N balance.

In this study we evaluated the effect of P acquisition during the growth period based on its subsequent effect on barley yield using two different P sources, either superphosphate (SP), a soluble P source, or meat and bone meal (MBM), representing a low-solubility P source (Ylivainio et al., 2008).

Tässä selvityksessä tarkastellaan missä maatalouden ravinnekuormitukseen kohdistuvan nykyisen ohjauksen keskeiset ongelmat ovat, mitä hyötyjä ja muita huomioon otettavia seikkoja liittyy mahdollisten verojen käyttöön sekä mihin maatalouden vesistökuormitusta rajoittavassa ympäristöohjauksessa tulisi tulevaisuudessa kiinnittää huomiota. Kehitettävät asiat liittyvät toisaalta toimenpiteiden kohdentamiseen ja toisaalta ohjauksen kannustavuuteen. Selvityksen vertailukohtana käytetään Euroopan Unionin yhteistä maatalouspolitiikkaa sekä siihen liittyvää ympäristötukijärjestelmää erityisesti tukijärjestelmän niiden toimenpiteiden osalta, joilla pyritään suoraan vaikuttamaan ravinteiden käyttöön maataloudessa. Selvityksessä todetaan, ettei lannoiteverolla yksinään pystytä korvaamaan nykyistä ympäristötukijärjestelmää eikä se toisaalta olisikaan mahdollisen veron tarkoitus. Nykyisessä järjestelmässä lannoitevero olisi ennen kaikkea tiedollisen ohjauksen tehostamiskeino. Lannoiteveron avulla olisi mahdollista jossain määrin tehostaa maatalouden vesiensuojelua. Maatalouden koko tuki- ja verojärjestelmän tarkastelu ennen seuraavaa tukijärjestelmäuudistusta olisi perusteltu etenemistapa.

P and N losses were highest from the conventional crop rotation. The losses were most affected by single management practices. The four-year study is, however, too short for soil derived, long-term differences to come fully out in the leaching losses.

1 Introduction Traditional arable cropping systems in the EU have been progressively simplified to monocropping systems, with high external inputs through mineral and organic fertilizers, pesticides and conventional tillage (CT). Thus, various crop diversification strategies such as crop rotation, intercropping and multiple cropping, as well as low-input management practices have been promoted to sustain crop productivity while maintaining environmental quality and ecosystem services. Actually, European arable area has high opportunities for sustainable intensification through crop rotation, conservation tillage (minimum (MT) or no-tillage (NT)) and fertilization management. It has been also argued that diversification of production systems can lead to better food security (Scherer et al., 2018) and economic sustainability of farms (de Roest et al., 2018), since it contributes to natural pest control, pollination, nutrient recycling, soil structure and fertility conservation, carbon sequestration, and water provision. In the Diverfarming project (www.diverfarming.eu), the preliminary objective was to identify, with an exhaustive literature review, the best crop diversification systems and farming practices to be tested and validated in the field experiments to be planned in the different European pedoclimatic regions. Understanding the expected effects of diversified cropping systems and management options on the resilience and sustainability of agroecosystems in different regions, may promote the adoption of appropriate practices and help to select a suitable method for each production system and environment, thus improving farm management and increasing revenues. 2 Materials and Methods We conducted a data-analysis to evaluate the expected effects of the existing alternatives for crop diversification and environmentally-sound farming management for arable crops in four selected European pedoclimatic regions (Atlantic, Boreal and Mediterranean North and South), and typical cropping systems (fodder grains, leys and mixtures, autumn-winter and spring-summer cereals). The dataset included sitespecific environmental data (e.g. mean annual temperature and rainfall), soil tillage (e.g. no-tillage, minimum and conventional tillage), fertilization management (none, mineral, mixed, organic), cropping system (monoculture, rotation, intercropping, multiple cropping), crop production e.g. grain in cereals and above ground biomass in fodder crops (CP), soil organic carbon (SOC) concentration at the end of the experiment, and soil texture group according to USDA classification. Data included in the analysis depended on the following general criteria: study period (at least one full year), only field experiments (no laboratory or pot experiments), and neither studies specific for GHGs emissions, soil biological and physical parameters, metaanalyses nor modelling studies were considered. Moreover, studies providing SOC content by soil layers under tillage management were also considered. The final selected comparisons were 1165 from a total of 80 references. The diversified (Div) and the control (Cont) treatments of each experiment were evaluated based on the percentage change of the considered response variable, i.e. CP, and SOC. Since we used the ratio between the difference (Div – Cont) and the Cont, we could eliminate the differences due to the different CP levels and SOC analytical methods among studies (Eqs. 1-2): Percentage change (CP) = 100 × (CPDiv – CPCont) / CPCont (Eq. 1) Percentage change (SOC) = 100 × (SOCDiv – SOCCont) / SOCCont (Eq. 2) Changes of CP and SOC were analyzed evaluating the effects of crop diversification, tillage and fertilization management, and further by environmental (e.g. climate) or soil parameters (e.g. texture). Data were represented by Box-Whisker plots (central point means, and 95% confidence interval CI). Responses were considered significantly different if their 95% CIs did not overlap, and significantly different from the controls if the 95% CIs did not overlap with zero. 3 Results Compared to monoculture, diversified cropping systems with longer crop rotations (at least 3 years) significantly increased CP by 12%, while the 2-years rotations showed a not-significant 5% increase. CP for intercropping were 11% higher compared to monoculture, though not statistically different. The average effect on CP of multiple cropping was 1%, close to zero (-0.4%) in the Mediterranean region while ranged from -4.3% to 12.6% in the Boreal region (average 3.9%). SOC increased by 13% as average in diversified systems compared with monoculture, and the introduction of legume crops in the rotations significantly increased SOC by 13%. Average SOC increases were 11% higher in semiarid conditions than in humid and sub-humid climates (about 3%). In relation to conservation tillage, CP was 12% higher in NT compared with CT, and was more effective on CP in silty clay loam soils and in arid and semi-arid climates. In addition, NT was more effective in increasing SOC than MT. Significant SOC increases by conservation tillage management were found with organic and mixed fertilization (27 and 5% respectively) and crop rotations (5%). Results by soil layers showed an average SOC increase ranging from 14 to 45% in the top 15 cm with conservation tillage management compared to conventional deep tillage, while SOC decreased by about 10% as average in deeper soil layers below 15 cm. In relation to fertilization management, organic fertilization with manure or slurry increased CP (37-40%), and mineral fertilization was particularly effective with the introduction of cover crops (56%), combined with crop residues (24%) or with manure and crop residues (41%). Furthermore, CP increased with crop residue incorporation (39%) or mulching under conservation tillage (39%) and longer crop rotations (39%). Compared to the control treatment with mineral fertilization, organic fertilization showed the highest and significant SOC increases (25%). Fertilization average effect on SOC was higher for cereal crops in the Mediterranean region (about 25%) compared to fodder crops in the Atlantic and Boreal areas (about 10%), and in loamy textures (about 23%). 4 Discussion and Conclusions In our data-analysis, longer crop rotations resulted in higher CP compared to monoculture. Intercropping was mainly adopted in the humid conditions of the Atlantic and Boreal regions and showed a general lower effect on CP compared to traditional rotations. Results also showed the need of improvements in the management of multiple cropping systems, as indicated by Bedoussac and Justes (2010). In general, results point to the direction that conversion from the traditional monocropping systems, with intensive tillage and mineral fertilization, to alternative systems based on cropping diversification through the use of crop rotations, notillage and organic fertilization results in a better crop performance and in the accrual of soil C. Diversification with longer rotations, NT and organic fertilization management increased both CP and SOC in European arable systems. Notwithstanding, crop diversification and environmentally-sound farm management strategies are often negatively perceived by farmers for a possible decrease in yields and economic benefits that are often coupled with higher machinery investments. Globally, regional differences related to climate and soil texture specific responses should be considered to target local measures to improve soil management., {"references":["Bedoussac, L., Justes, E., 2010. The efficiency of a durum wheat-winter pea intercrop to improve yield and wheat grain protein concentration depends on N availability during early growth. Plant Soil 330, 19–35.","de Roest, K., Ferrari, P., Knickel, K., 2018. Specialisation and economies of scale or diversification and economies of scope? Assessing different agricultural development pathways. J. Rural Stud. 59, 222–231.","Scherer, L.A., Verburg, P.H., Schulp, C.J.E., 2018. Opportunities for sustainable intensification in European agriculture. Global Environ. Change 48, 43–55."]}

1 Introduction Traditional arable cropping systems in the EU have been progressively simplified to monocropping systems, with high external inputs through mineral and organic fertilizers, pesticides and conventional tillage (CT). Thus, various crop diversification strategies such as crop rotation, intercropping and multiple cropping, as well as low-input management practices have been promoted to sustain crop productivity while maintaining environmental quality and ecosystem services. Actually, European arable area has high opportunities for sustainable intensification through crop rotation, conservation tillage (minimum (MT) or no-tillage (NT)) and fertilization management. It has been also argued that diversification of production systems can lead to better food security (Scherer et al., 2018) and economic sustainability of farms (de Roest et al., 2018), since it contributes to natural pest control, pollination, nutrient recycling, soil structure and fertility conservation, carbon sequestration, and water provision. In the Diverfarming project (www.diverfarming.eu), the preliminary objective was to identify, with an exhaustive literature review, the best crop diversification systems and farming practices to be tested and validated in the field experiments to be planned in the different European pedoclimatic regions. Understanding the expected effects of diversified cropping systems and management options on the resilience and sustainability of agroecosystems in different regions, may promote the adoption of appropriate practices and help to select a suitable method for each production system and environment, thus improving farm management and increasing revenues. 2 Materials and Methods We conducted a data-analysis to evaluate the expected effects of the existing alternatives for crop diversification and environmentally-sound farming management for arable crops in four selected European pedoclimatic regions (Atlantic, Boreal and Mediterranean North and South), and typical cropping systems (fodder grains, leys and mixtures, autumn-winter and spring-summer cereals). The dataset included sitespecific environmental data (e.g. mean annual temperature and rainfall), soil tillage (e.g. no-tillage, minimum and conventional tillage), fertilization management (none, mineral, mixed, organic), cropping system (monoculture, rotation, intercropping, multiple cropping), crop production e.g. grain in cereals and above ground biomass in fodder crops (CP), soil organic carbon (SOC) concentration at the end of the experiment, and soil texture group according to USDA classification. Data included in the analysis depended on the following general criteria: study period (at least one full year), only field experiments (no laboratory or pot experiments), and neither studies specific for GHGs emissions, soil biological and physical parameters, metaanalyses nor modelling studies were considered. Moreover, studies providing SOC content by soil layers under tillage management were also considered. The final selected comparisons were 1165 from a total of 80 references. The diversified (Div) and the control (Cont) treatments of each experiment were evaluated based on the percentage change of the considered response variable, i.e. CP, and SOC. Since we used the ratio between the difference (Div – Cont) and the Cont, we could eliminate the differences due to the different CP levels and SOC analytical methods among studies (Eqs. 1-2): Percentage change (CP) = 100 × (CPDiv – CPCont) / CPCont (Eq. 1) Percentage change (SOC) = 100 × (SOCDiv – SOCCont) / SOCCont (Eq. 2) Changes of CP and SOC were analyzed evaluating the effects of crop diversification, tillage and fertilization management, and further by environmental (e.g. climate) or soil parameters (e.g. texture). Data were represented by Box-Whisker plots (central point means, and 95% confidence interval CI). Responses were considered significantly different if their 95% CIs did not overlap, and significantly different from the controls if the 95% CIs did not overlap with zero. 3 Results Compared to monoculture, diversified cropping systems with longer crop rotations (at least 3 years) significantly increased CP by 12%, while the 2-years rotations showed a not-significant 5% increase. CP for intercropping were 11% higher compared to monoculture, though not statistically different. The average effect on CP of multiple cropping was 1%, close to zero (-0.4%) in the Mediterranean region while ranged from -4.3% to 12.6% in the Boreal region (average 3.9%). SOC increased by 13% as average in diversified systems compared with monoculture, and the introduction of legume crops in the rotations significantly increased SOC by 13%. Average SOC increases were 11% higher in semiarid conditions than in humid and sub-humid climates (about 3%). In relation to conservation tillage, CP was 12% higher in NT compared with CT, and was more effective on CP in silty clay loam soils and in arid and semi-arid climates. In addition, NT was more effective in increasing SOC than MT. Significant SOC increases by conservation tillage management were found with organic and mixed fertilization (27 and 5% respectively) and crop rotations (5%). Results by soil layers showed an average SOC increase ranging from 14 to 45% in the top 15 cm with conservation tillage management compared to conventional deep tillage, while SOC decreased by about 10% as average in deeper soil layers below 15 cm. In relation to fertilization management, organic fertilization with manure or slurry increased CP (37-40%), and mineral fertilization was particularly effective with the introduction of cover crops (56%), combined with crop residues (24%) or with manure and crop residues (41%). Furthermore, CP increased with crop residue incorporation (39%) or mulching under conservation tillage (39%) and longer crop rotations (39%). Compared to the control treatment with mineral fertilization, organic fertilization showed the highest and significant SOC increases (25%). Fertilization average effect on SOC was higher for cereal crops in the Mediterranean region (about 25%) compared to fodder crops in the Atlantic and Boreal areas (about 10%), and in loamy textures (about 23%). 4 Discussion and Conclusions In our data-analysis, longer crop rotations resulted in higher CP compared to monoculture. Intercropping was mainly adopted in the humid conditions of the Atlantic and Boreal regions and showed a general lower effect on CP compared to traditional rotations. Results also showed the need of improvements in the management of multiple cropping systems, as indicated by Bedoussac and Justes (2010). In general, results point to the direction that conversion from the traditional monocropping systems, with intensive tillage and mineral fertilization, to alternative systems based on cropping diversification through the use of crop rotations, notillage and organic fertilization results in a better crop performance and in the accrual of soil C. Diversification with longer rotations, NT and organic fertilization management increased both CP and SOC in European arable systems. Notwithstanding, crop diversification and environmentally-sound farm management strategies are often negatively perceived by farmers for a possible decrease in yields and economic benefits that are often coupled with higher machinery investments. Globally, regional differences related to climate and soil texture specific responses should be considered to target local measures to improve soil management.

A Thesis applying for the degree of Doctor of Philosophy in Agriculture Present thesis studies the impacts of slurry fertilization on nutrient leaching and on the efficiency of using activated carbon (AC) as a measure in its reduction. In addition research assesses the cattle slurry as a source of antibiotic resistance genes (ARGs) entering grassland soil. It was hypothesised that N and K leaching depends on fertilizer type, N rate used and sward type. Also it was assumed that the use of AC reduces N and K leaching and cattle slurry increases ARGs abundance in fertilized soil. The objective of the study was to assess the effect of fertilizer type (mineral NPK, cattle slurry), N rate used (0, 60, 120, 180 kg ha-1), sward botanical composition (grass-clover and grass-only sward) and AC incorporation into the soil on N and K leaching and also to study the effect of cattle slurry fertilization on the abundance of ARGs in grassland soil. Research showed that N leaching in grassland depends on used fertilizer type and it was lower with mineral fertilizer use compared to cattle slurry. Nitrogen leaching did not depend on N rate used, but it was affected by sward botanical composition and was lower in grass-clover compared to grass-only sward. Potassium losses did not depend on used nutrient source, rather it was increased only with unbalanced N: K ratio at fertilization. After vegetative period N leaching depended mainly on weather conditions, more precisely on the length of the period the soil was frozen. Leaching of K resembled to the vegetative period and depended apparently on the N: K balance in the soil achieved before the end of vegetative period. Activated carbon incorporation into the soil reduced only NO3--N leaching irrespective of the fertilizer treatment, but increased that of K. Cattle slurry and its digestate were a considerable source of antibiotic resistance genes and their use increased soil blaCTX-M and sul1 concentrations and mineral fertilizer tetA gene abundance. Doktoritöö uurib vedelsõnniku mõju toitainete leostumisele rohumaal ning aktiivsöe (AC) efektiivsust selle vähendamisel. Lisaks hindab töö vedelsõnnikuga väetamise rolli antibiootikumi resistentsusgeenide (ARG) levikule rohumaa mullas. Hüpoteesiks oli, et N ja K leostumine sõltub kasutatud väetisest, N normist ja taimiku botaanilisest koosseisust. Samuti, et AC vähendab N ja K leostumist ning veise vedelsõnnik suurendab ARGde arvukust rohumaa mullas. Uurimistöö eesmärk oli hinnata väetise liigi (mineraalne NPK ja veise vedelsõnnik), N normi (0,60, 120 ja180 kg ha-1), taimiku botaanilise koosseisu (kõrrelised-valge ristik ja kõrrelised taimik) ning AC mulda viimise mõju N ja K leostumisele ning selgitada vedelsõnnikuga väetamise mõju ARGde arvukusele rohumaa mullas. Tulemustest selgus, et N leostumine rohumaal sõltus kasutatud väetise liigist ning oli mineraalse NPK väetise kasutamisel vedelsõnnikuga võrreldes väiksem. Lämmastiku leostumine ei sõltunud kasutatud N normist, kuid sõltus taimiku botaanilisest koosseisust ning oli väiksem kõrrelised-valge ristik taimikust võrreldes kõrreliste taimikuga. Kaaliumi leostumine ei sõltunud toitainete allikast, vaid oli mõjutatud N: K suhtest väetamisel. Väljaspool vegetatsiooniperioodi sõltus leostunud N kogus ilmastikust ning peamiselt perioodi pikkusest, mil muld oli külmunud. Kaaliumi leostumine sarnanes aga vegetatsiooniperioodile ning sõltus ilmselt mulla N: K suhtest, mille määras vegetatsiooniperioodi aegne väetamine. Aktiivsöe lisamine mulda vähendas vaid NO3−-N leostumist sõltumata kasutatud väetise liigist, kuid suurendas K leostumist. Nii veise vedelsõnnik kui selle digestaat sisaldasid olulisel määral ARGsid ning nende kasutus suurendas mulla blaCTX-M ja sul1 ning mineraalväetis tetA arvukust. Publication of this dissertation is supported by the Estonian University of Life Sciences.

Deterioration in the quality of surface waters worldwide is associated with losses of phosphorus (P) from diffuse sources. Controlling such losses is rather difficult, but their significance in reducing the effects of eutrophication is crucial. Phosphorus losses from diffuse sources represent a significant share of total P transfers to surface waters. Researchers have studied and implemented numerous methods to curb non-point P losses during the past decades, but such studies have generally been insufficient to change the impact of agriculture on the course of surface waters eutrophication. For example, even though inputs of P and nitrogen (N) into the Baltic Sea have significantly decreased over the past two decades, the Baltic Sea still represents a eutrofied body of water. To further reduce P losses from agriculture, current P abatement methods must be amended with additional techniques. One such technique involves the use of P-retaining materials as filters placed in ditches within agricultural areas. This study encompasses a set of laboratory, meso- and large-scale set-ups to identify potential P-retaining materials available in Finland for the treatment of agricultural runoff. The laboratory studies investigated the P retention potential of fresh and weathered Ca-rich (Sachtofer PR®, steel slag, Filtra P®, Filtralite P®) as well as Fe-rich materials (mine drainage residual - MDR) in flow-through tests when applying a high influent P concentration of 50 mg/l. The weathering process served to leach out soluble species such as Ca2+ and OH-, thus mimicking aged filters. In addition, desorption/dissolution tests involved the placement of P-saturated materials in solutions of variable pH as well as one-month extraction with large volumes of water. Sachtofer PR®, steel slag, Filtra P® and MDR retained relatively large amounts of P, varying between 12 and 24 mg P/g material. As desorption/dissolution tests show, two distinct mechanisms controlled the materials retention of P: precipitation of Ca-phosphates and sorption of P onto Fe-hydroxide surfaces. As the most promising material, Sachtofer PR® was further employed in meso- (20 kg) and large-scale (7 tons) filters that treated influents with significantly lower P concentrations, up to 6 mg/l and 0.25 mg/l, respectively. The feed solution in the meso-scale filter alternated between P-enriched tap and river waters, whereas the large filter treated agricultural runoff from 17 ha of cropland. As the application of Sachtofer was scaled up, and influent P concentration declined, cumulative P retention decreased from 19 mg P/g in the laboratory to 0.06 mg P/g in the field. The meso-scale experiment indicated that the P removal efficiency decreased also due to the presence of dissolved organic carbon (DOC) in the influents; the filter retained about 10% of the total amount of DOC added to the system. As for the large filter, the formation of preferential water pathways resulting from material decomposition and freezing-thawing cycles greatly reduced its efficiency. Moreover, in high flow conditions during spring snowmelts or high rainfalls, the large filter treated only a small portion of the incoming flow; the estimated treated flow during the entire test period was about 20%. Maintaining a low effluent limit is rather challenging, and such techniques should instead serve to remove a significant part (e.g., 30-40%) of the dissolved mass of P in agricultural runoff. To justify the potential P recovery from spent filters and to ensure cost-efficiency, the P-retaining material should reach a significant P saturation. In addition, P removal structures should be coupled with other best management practices to minimize losses of P from agriculture. Keywords: P-retaining materials, P retention, precipitation, sorption, upscaled application, dissolved organic carbon, material alteration, preferential flows, high flows, filters, permeable reactive barriers