<p>In ambition to produce more and better harvests, artificial fertilizers are used to produce a better growth of crops in the agriculture landscape. This contributes to leakage of nutrients. Our forests also exhibit a leakage of nutrients. Air pollution contributes to more nutrients. High precipitation with high water flows as a consequence seems currently to occur more frequently in the county of Halland. The high precipitation could be a consequence of climate changes. Increased precipitation increases the flow of nutrients into watercourses and causes eutrophication problems. For the best possible nutrient uptake, wetlands should be designed after local circumstances. One way is to construct production wetlands where biomass in form of plants is harvested to remove nutrients. In order to get the best possible decrease of eutrophication, production wetlands should be constructed on a large scale. Often flooded areas are suited for constructing new production wetlands. The production wetland could be planted with common reed (Phragmites australis) which grows fast and creates a large biomass and therefore a high nutrient uptake. In order to take in water and emptying a production wetland before harvesting, it should also be constructed with controllable in - and outflow of water. Harvesting is a sensitive aspect and the production wetland should be constructed so harvesting with agricultural machines is possible to reduce the costs. The harvested biomass should be used in biogas production. The material that remains after digestion in the biogas plant can be used as fertilizer on agricultural land to replace artificial fertilizers. This contributes to more ecological agriculture where artificial fertilizers are forbidden. From an environmental point of view, this process is clearly the best way where nutrients can be re-circulated.</p>

In ambition to produce more and better harvests, artificial fertilizers are used to produce a better growth of crops in the agriculture landscape. This contributes to leakage of nutrients. Our forests also exhibit a leakage of nutrients. Air pollution contributes to more nutrients. High precipitation with high water flows as a consequence seems currently to occur more frequently in the county of Halland. The high precipitation could be a consequence of climate changes. Increased precipitation increases the flow of nutrients into watercourses and causes eutrophication problems. For the best possible nutrient uptake, wetlands should be designed after local circumstances. One way is to construct production wetlands where biomass in form of plants is harvested to remove nutrients. In order to get the best possible decrease of eutrophication, production wetlands should be constructed on a large scale. Often flooded areas are suited for constructing new production wetlands. The production wetland could be planted with common reed (Phragmites australis) which grows fast and creates a large biomass and therefore a high nutrient uptake. In order to take in water and emptying a production wetland before harvesting, it should also be constructed with controllable in - and outflow of water. Harvesting is a sensitive aspect and the production wetland should be constructed so harvesting with agricultural machines is possible to reduce the costs. The harvested biomass should be used in biogas production. The material that remains after digestion in the biogas plant can be used as fertilizer on agricultural land to replace artificial fertilizers. This contributes to more ecological agriculture where artificial fertilizers are forbidden. From an environmental point of view, this process is clearly the best way where nutrients can be re-circulated.

Syftet med uppsatsen är att redovisa för det svenska jordbrukets påverkan på kväve-och fosforutsläpp från ekologiska och konventionella jordbruk, genom att jämföra kväve-och fosforhalter i jordbruksmarks avrinngsområde. Anledningen till varför kväve-och fosforhalterna är valda är på grund av att dessa två ämnen har en stor inverkan på övergödningen och vattenkvaliteten. Metoden är en kvantitativ undersökningsmetod, där syftet och frågeställningarna har besvarats genom att jämföra kväve-och fosforhalter vid avrinningsområden från jordbruksområden under åren 2009-2014 med att andelen ekologiskt odlad jordbruksmark ökar i hektar, detta för att se om det finns ett samband i kväve-fosfor halter och ökad andel hektar ekologiskt odlad jordbruksmark. För att ta reda på den påverkan ekologiskt odlad jordbruksmark har på övergödningen har det i metoden gjorts en uträkning av hur stor del av den totala jordbruksmarken som är ekologisk respektive konventionell mellan åren 2010 och 2011, detta för att under denna tidsperiod är det då den ekologiskt odlade jordbruksmarken ökade som mest. Informationen om kväve-och fosforhalter vid avrinningsområden kommer från Sveriges 17 län (de län det finns data för), detsamma gäller för informationen om ekologiskt odlad jordbruksmark. Tillvägagångssättet kommer att redovisa för kväve-och fosforhalter vid de 17 länen i diagram och punktdiagram för ekologiskt odlad jordbruksmark. Länen delas i bilagan upp i tre regioner, norr, mellan och söder, detta för att se om det finns samband eller olikheter mellan Sveriges län. Diagrammen redovisar för åren 2009-2014. Resultatet visar på att det finns ett samband mellan att kväve-och fosforhalterna ökar och att andelen ekologiskt odlad jordbruksmark ökar i hektar.

This essay discusses the Laholm’s bay and its eutrofication problems. The question of issue is: Have the efforts to limit the eutrofication in the Laholm’s bay been effective? What is the local actor’s opinion whether the measures have been effective or not? What efforts have been made to prevent the leakage of nutrients from fields and forestland? The Laholm's bay is located in the south part of the Swedish west coast. The problem was noticed in the 1960´s by local fishermen that experienced a lack of catch. Attention was drawn to the problem and it turned out that the bay was experiencing oxygen depletion The Laholm’s bay drainage basin is drained by five streams: Lagan, Nissan, Fylleån, Genevadsån and Stensån. The Laholm’s bay is especially sensitive to eutrofication because of its shallowness and has a medium depth of only 15 meters. In this bay nitrogen is the limiting nutrient. There are several sources for nitrogen and agricultural land as well as woodlands are the main cause. Interviews has been with wide range of persons to get a grip of what have been done and what is left to do in the area. The interviews have been divided between municipalities, county administration, the Federation of Swedish Farmers, scientist and farmers. The farmers along with the whole agriculture industry in the Laholm’s bay have put a lot of effort to reduce the nutrients leakage. The efforts have not given any clear results and the nitrogen levels are still the same. Data from small forest rivers and small rivers in agriculture land are showing a much more clear result. Agriculture land is in these measurements showing a slightly decrease in nitrogen levels. Forrest rivers are on the other hand showing an increase. It can be concluded that the efforts to reduce the eutrofication have been partly effective. Stronger regulations for all nutrients leakage source are necessary if eutrofication problems are going to show any significant improvement. It’s important to keep in mind that it’s a slow process that involves that efforts are made in several countries.

In Halland, agriculture is the major source of eutrophication of water. In the study, synoptic sampling were performed in the three watercourses Nyrebäcken, Skintan and Vinån all located in the county of Halland. Sampling occurred during the period February to May on three occasions with different flow rates: high, low and base flow. Samples were taken in the mainstream and tributaries with intention to show how big the impact of eutrophication it is in the water and  to assess the impact of the tributaries The results show that all watercourses are affected by eutrophication. Nyrebäcken has the highest concentrations of nitrogen and phosphorus in the mainstream, then Skintan and last Vinån. Vinån is much less affected by phosphorus than the other watercourses, which may depend on the surrounding landscape and that the edges of the watercourse are less steep than at Nyrebäcken and Skintan. The concentration in the tributaries varies widely, from low concentrations to extremely high. In all watercourses there are tributaries that have a big impact on the mainstream, just as there are tributaries that have a small impact. The concentration also varies with the different flows and in generally the highest concentrations of nitrogen and phosphorus are measured during high flow. To estimate the impact of the tributaries the results of total nitrogen and total phosphorus have been classified according to classification system previously used in Sweden. The classification means a rating from 1 to 5 where 1 is the lowest and 5 the highest. The classification has been made for each tributary in the respective watercourses at different flows. The mainstream was classified according to the mean of all sample points in the mainstream at the respective flow. Sampling was only done on three occasions during a short period and to improve the results further sampling have to be done.

In November 2007 the countries around the Baltic Sea signed the Baltic Sea Action Plan (BSAP). The action plan was an initiative from HELCOM due to the environmental status in the Baltic Sea. The action plan implemented a new approach with measures targeting the whole ecosystem. Eutrophication, hazardous substances, biodiversity and maritime activities constituted the main segments. The parties were to establish national implementation plans to fulfil the BSAP goals, which shall lead to good environmental status in the Baltic Sea by 2021.   The aim of this thesis is to investigate the points in common regarding conceptions of eutrophication in the Baltic Sea between the management, the science, the media and the public. There are often complex connections between scientific knowledge and decision-making. With the purpose to elucidate these connections the risk management of eutrophication was compared with the scientific knowledge in the area along with the perceptions of the public and media. The implementation plans of the HELCOM parties differ in both content and ambitions. Overall the implementation plans are technical and many of them give no background descriptions to the causes of eutrophication. The scientific uncertainty that surrounds the calculation models of eutrophication is mentioned in about half of the implementations plans. Some uncertainty is mentioned due to the timescale of the effects of the measures. This can be compared with the fact that some scientists mean that the BSAP goals are unrealistic. Several parties mention the agriculture as an important sector for the reduction of the nutrient supply to the Baltic Sea. The Russian, Lithuanian and Estonian implementation plans also put forward the municipality treatment plants as important actors. There is a big difference between how many times the notion “eutrophication” is mentioned in the implementation plans. In the German implementation plan the notion is mentioned most frequently (29 times), while the Danish implementation plan only mention the notion twice. In the Finnish, Polish and German implementation plans eutrophication is described as a big threat. Only in the Latvian, Polish and German implementation plans eutrophication is described as a risk. The analysis of the implementation plan content shows that the parties has not succeeded to fully use the risk notion in relation to eutrophication. This can affect the risk governance, but also the perception of eutrophication among different stakeholders. Both media and politics affect the complex interactions that constitute the fundament of the relationship between scientific knowledge and public risk awareness. The consequence of eutrophication that is given most of the space in the Swedish newspaper Dagens Nyheter is algal growth. 73 % of the Swedes consider the algal growth as a rather big issue or a very big issue. A plausible conclusion is that there is a connection between the descriptions of eutrophication in Swedish media and the perceptions and knowledge of eutrophication by the Swedish respondents. The perceptions and management of eutrophication in the Baltic Sea are surrounded by complex interactions, uncertainty in the scientific basis and ambiguous opinions. Despite this eutrophication is often treated as a simple risk. For the purpose of successful implementation of the action plans is it important that the public participate in the elaboration of the risk measures. To accomplish real change it might be necessary to make the complex interactions more visible and to make the public participate more.

Biokol, dvs pyrolyserat organiskt material som tillförs marken, är erkänt för sina jordförbättrande egenskaper. Ny forskning uppmärksammar nu andra användningsområden för biokol såsom adsorption av oönskade föreningar samt som effektiv kolsänka inom klimatarbetet. Näringsläckande åkrar bidrar årligen med stora kvantiteter växttillgänglig näring och relaterad eutrofiering av sjöar, vattendrag och i förlängningen till Östersjön. Eutrofieringen ska enligt EUs ramdirektiv för vatten liksom Sveriges 16 miljömål minskas. Det här examensarbetet syftade till att utreda om ett biokolsfilter kan utformas och installeras i anslutning till åkermarkers dräneringsdiken för att minska läckaget av näringsämnen från jordbruket. Genom att sedan sprida det näringsmättade filtermaterialet på närliggande åkermark önskades filterlösningen lokalt bidra till ett mer slutet kretslopp med avseende på kväve och fosfor samtidigt som biokolets jordförbättrande egenskaper utnyttjas. För att erhålla önskad reningseffekt i ett filter bör tre fysikaliska egenskaper kombineras, dess hydrauliska konduktivitet K (m/s), sammanlagd materialyta tillgänglig för kemisk reaktion (specifik yta (m2/g TS)) samt ytans reaktivitet. Alla dessa egenskaper är till viss del beroende av filtermaterialets partikelstorlek. Biokolets hydrauliska konduktivitet bestämdes experimentellt med hjälp av Darcys lag vilket gav en konduktivitet på 10-2 – 10-1 m/s. Partikelstorleksfördelningen bestämdes genom mekanisk siktning till ett intervall på mellan 0-8 mm, varav 80 viktprocent återfanns i intervallet 1,7 – 5 mm. Utifrån resultaten beräknades att biokol (2 – 6 mm) kunde ge en flödeskapacitet på ca 1 – 7 l/s.  Biokolets ytreaktivitet har inte kunnat bestämmas i denna studie. Det i studien utformade filtret placerades i ett dräneringsdike i Eskilstunaregionen inuti en befintlig vägtrumma med diameter 80 cm. Vattenföringen i diket uppmättes initialt till att variera mellan 1,5 – 7 l/s. Filterdesignen utgjordes av en halvcylinder i geotextil innehållandes 0,11 m3 biokol. Längden var 1,2 m med en tvärsnittsarea på 0,09 m2 och beräknad flödeskapacitet genom filtret vid mättad strömning var 1,2 l/s. Filterfunktionen utvärderades genom totalt tio vattenprovtagningar av vattnet vid in- och utlopp under perioden 15 maj - 1 juli 2014. Vattenproverna analyserades med avseende på näringsämnen kopplade till övergödning (PO4-P, NH4-N och NO3-N). Filtermaterialet, biokol, utvärderades med skakextraktion samt utifrån dess innehåll av metaller relaterade till fosforbindningar (Al, Fe, Mg, Mn och Ca). Resultaten visade generellt på högre halter av fosfor och kväve i utloppet än i inloppet. Även resultatet från skakextraktionen pekade på högre halter av PO4-P och NO3-N i extraktionsvattnet efter skakning. Utifrån denna studie ger biokolsfiltret ingen reduktion av näringsämnestransporten i dräneringsvatten från åkermark. Snarare indikeras en utlakning av PO4-P, NH4-N och NO3-N med det använda biokolet vilket troligen delvis berodde på att biokolet hade en negativ nettoytladdning. Den framtagna filterlösningen i den här studien antogs därför inte kunna bidra till ett mer slutet kretslopp av näringsämnen vid åkermark. / Biochar, i. e. pyrolyzed organic material applied to soil, is traditionally recognized for its soil-improving properties. New research has revealed other areas for biochar such as adsorption of unwanted compounds as well as in climate change initiatives as an effective carbon sink. Cropland leaks nitrogen and phosphorus and annually contributes with large quantities of plant-available nutrients increasing eutrophication of lakes, rivers, and finally the Baltic Sea. Both the EU WFD and the SGFTE state that active measures must be taken to reduce the eutrophication. The purpose of this master thesis was to investigate whether a biochar filter could be designed and installed in drainage ditches from farmland to reduce nutrient losses from agriculture. When nutrient-saturated, the content of the filter could then be spread on nearby farmland. The filter solution could in that case locally contribute to a more closed-loop with respect to nitrogen and phosphorus while the soil-enhancing properties of biochar were utilized. In order for a filter solution to obtain desired purification rate, three physical and chemical properties of the filter content were to be considered, its hydraulic conductivity K (m/s), total mineral surface available for chemical reaction (specific surface area (m2/g DS)) and the surface reactivity. All these properties are to some extent dependent on the filter material distribution of particle sizes. Hydraulic conductivity within the biochar was experimentally determined using Darcy's law which gave a hydraulic conductivity in the order of 10-2 – 10-1 m/s. The particle size distribution was determined by mechanical sieving to a range between 0 – 8 mm, of which 80 percent by weight was recovered in the range from 1.7 to 5 mm. It was calculated that the biochar (2 – 6 mm) filter could provide a flow capacity of about 1 – 7 l/s. The filter, designed in this thesis, was placed in a drainage ditch in Eskilstuna inside an existing culvert with a diameter of 80 cm. The water discharge in the ditch was initially measured to vary between 1.5 to 7 l/s. The filter design consisted of 0.11 m3 of biochar wrapped in a half cylinder made of geotextile. The length was 1.2 m with a cross-sectional area of 0.09 m2. The calculated flow rate through the filter, at saturated flow, was 1.2 l/s. The filter function was evaluated by a total of ten sets of water samples from both inlet and outlet taken during the period May 15 to July 1, 2014. The water samples were analyzed for nutrients linked to eutrophication (PO4-P, NH4-N and NO3-N). The biochar used as filter material was evaluated by extraction through shaking and also by its content of metals related to phosphorus bindings (Al, Fe, Mg, Mn, and Ca). A majority of the results indicated higher levels of phosphorus and nitrogen in the outlet than the inlet. Also the results from extraction showed higher levels of PO4-P and NO3-N in the extraction solution after shaking. Based on this study, this filter of biochar gave no reduction of nutrient transport in drainage water from the agricultural land. Instead, leaching of PO4-P, NH4-N and NO3-N were indicated with the used biochar. This may in part be caused by the fact that most biochar has a negative net surface charge. The designed filter solution in this study is therefore assumed not to contribute to a better closed nutrient cycle in agricultural land.

Eutrophication is a major problem in many parts of the world today. Eutrophication means that more nutrients are added than nature can absorb, which can lead to algal blooms, overgrowth and sometimes even a lack of oxygen at the seabeds. One of the environmental quality goals in Sweden is No eutrophication and this goal is far from being achieved as extensive problems with eutrophication remain. Phosphorus is a substance that plays a significant role in eutrophication. To find out how much phosphorus there is in a watercourse water samples are taken, usually monthly. However, this is too sparse and peaks with higher levels therefore risk being missed and the phosphorus load in the watercourse can thus be underestimated. However, the sampling frequency required to obtain more reliable results is too expensive to carry out as far too many samples would need to be taken. However, there are solutions to this problem. By using high-frequency turbidity measurements with the help of sensors in watercourses the monthly measurements can be supplemented and gaps filled. Turbidity can be used as an indirect measurement of the phosphorus content as there is a connection between turbidity and phosphorus. This report examines the relationship between turbidity and total phosphorus content for seven different watercourses. Relationships are also compared between different seasons and flows for two of the watercourses. In addition, the total phosphorus load of the different watercourses is calculated and a comparison is made between high-frequency turbidity measurements and grab samples to find out if sensors are suitable at the investigated site. For all stations there was a significant relationship between turbidity and the total phosphorus content. The relationship was in some cases different for different seasons and also for different flows. At some of the stations the relationship was improved when the parameters conductivity and TOC (Total organic carbon) were added to the analysis. The phosphorus load on the different watercourses varied with the season in a similar way for each station with a lower load in the summer and a higher one in the winter and spring. When comparing the load calculated on the basis of sensors and the load calculated on the basis of grab samples the sensors sometimes gave a higher value and sometimes a lower value. This indicates that grab samples in some cases may be sufficient while sensors in some cases may be an important complement as the grab samples could give an underestimated total phosphorus content.

No description available.

One of today's major environmental issues is algal blooms linked to eutrophication of lakes and oceans. That is a result of anthropogenic influence with nutrient loads (including phosphorus) from agriculture and industry, which benefits primary production (phytoplankton). Studies have shown that phosphorus availability in the water column can be limited by liming, therefore could be a way to counteract eutrophication. This was tested in the agriculturally surrounded lake Tåkern in southern Sweden, which in its present state is an internationally important bird lake and therefore in several respects would be affected by eutrophication. The purpose of this study was to investigate whether liming would be a good solution to solve any future eutrophication problems in Lake Tåkern. Liming experiments were performed in mesocosms during April 2015 with a mixture of limestone and slaked lime. Quantity and diversity of plankton and water chemical variables were measured before and after liming. Moreover, samples of phytoplankton from a similar experiment conducted in July 2014 were analyzed. Liming did not show any effect on neither phyto- nor zooplankton when performed in spring of 2015. During summer of 2014, there was an increase in number of phytoplankton (ml-1 ) and chlorophyll in controls while the study showed constant levels in treated mesocosms. For zooplankton there was no significant effects of liming on neither quantity nor diversity. Results of this study suggest that liming is not the most appropriate method to resolve eutrophication in Lake Tåkern.