Browsing by Subject "phosphorus"

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  • Västilä, Kaisa; Väisänen, Sari; Koskiaho, Jari; Lehtoranta, Virpi; Karttunen, Krister; Kuussaari, Mikko; Järvelä, Juha; Koikkalainen, Kauko (MDPI, 2021)
    Sustainability 13, 16
    Conventional dredging of ditches and streams to ensure agricultural drainage and flood mitigation can have severe environmental impacts. The aim of this paper is to investigate the potential benefits of an alternative, nature-based two-stage channel (TSC) design with floodplains excavated along the main channel. Through a literature survey, investigations at Finnish field sites and expert interviews, we assessed the performance, costs, and monetary environmental benefits of TSCs in comparison to conventional dredging, as well as the bottlenecks in their financing and governance. We found evidence supporting the expected longer-term functioning of drainage as well as larger plant and fish biodiversity in TSCs compared to conventional dredging. The TSC design likely improves water quality since the floodplains retain suspended sediment and phosphorus and remove nitrogen. In the investigated case, the additional value of phosphorus retention and conservation of protected species through the TSC design was 2.4 times higher than the total costs. We demonstrate how TSCs can be made eligible for the obligatory vegetated riparian buffer of the European Union agri-environmental subsidy scheme (CAP-AES) by optimising their spatial application with respect to other buffer measures, and recommend to publicly finance their additional costs compared to conventional dredging at priority sites. Further studies on biodiversity impacts and long-term performance of two-stage channels are required.
  • Paczkowska, J.; Rowe, Owen; Schluster, L.; Legrand, C.; Karlson, B.; Andersson, A. (2017)
    It is well-known that nutrients shape phytoplankton communities in marine systems, but in coastal waters allochthonous dissolved organic matter (ADOM) may also be of central importance. We studied how humic substances (proxy of ADOM) and other variables influenced the nutritional strategies, size structure and pigment content of the phytoplankton community along a south-north gradient in the Baltic Sea. During the summer, the proportion of mixotrophs increased gradually from the phosphorus-rich south to the ADOM-rich north, probably due to ADOM-fueled microbes. The opposite trend was observed for autotrophs. The chlorophyll a (Chl a): carbon (C) ratio increased while the levels of photoprotective pigments decreased from south to north, indicating adaptation to the darker humic-rich water in the north. Picocyanobacteria dominated in phosphorusrich areas while nanoplankton increased in ADOM- rich areas. During the winter-spring the phytoplankton biomass and concentrations of photoprotective pigments were low, and no trends with respect to autotrophs and mixotrophs were observed. Microplankton was the dominant size group in the entire study area. We conclude that changes in the size structure of the phytoplankton community, the Chl a: C ratio and the concentrations of photoprotective pigments are indicative of changes in ADOM, a factor of particular importance in a changing climate.
  • Isenberg, Stefan; Weller, Stefan; Kargin, Denis; Valic, Srecko; Schwederski, Brigitte; Kelemen, Zsolt; Bruhn, Clemens; Krekic, Kristijan; Maurer, Martin; Feil, Christoph M.; Nieger, Martin; Gudat, Dietrich; Nyulaszi, Laszlo; Pietschnig, Rudolf (2019)
    Invited for this month's cover picture are the groups of Professors Rudolf Pietschnig at the University of Kassel, Professor Dietrich Gudat at the University of Stuttgart and Professor Laszlo Nyulaszi at the Budapest University of Technology and Economics. The cover picture shows the thermally induced homolytic cleavage of the central P-P bond in a phosphorus-rich bis-ferrocenophane furnishing P-centered radicals (as evidenced by the computed spin-density highlighted in blue). The central P-6 unit in the title compound is a structural analog of the connecting unit in Hittorf's violet phosphorus, which links the orthogonally arranged tubular entities. A portrait of the German physicist Johann Wilhelm Hittorf is included. Read the full text of their Full Paper at 10.1002/open.201900182.
  • Hashemi, Fatemeh; Pohle, Ina; Pullens, Johannes W. M; Tornbjerg, Henrik; Kyllmar, Katarina; Marttila, Hannu; Lepistö, Ahti; Klove, Bjorn; Futter, Martyn; Kronvang, Brian (MDPI, 2020)
    Water 12 6 (2020)
    Optimal nutrient pollution monitoring and management in catchments requires an in-depth understanding of spatial and temporal factors controlling nutrient dynamics. Such an understanding can potentially be obtained by analysing stream concentration–discharge (C-Q) relationships for hysteresis behaviours and export regimes. Here, a classification scheme including nine different C-Q types was applied to a total of 87 Nordic streams draining mini-catchments (0.1–65 km2). The classification applied is based on a combination of stream export behaviour (dilution, constant, enrichment) and hysteresis rotational pattern (clock-wise, no rotation, anti-clockwise). The scheme has been applied to an 8-year data series (2010–2017) from small streams in Denmark, Sweden, and Finland on daily discharge and discrete nutrient concentrations, including nitrate (NO3−), total organic N (TON), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP). The dominant nutrient export regimes were enrichment for NO3− and constant for TON, DRP, and PP. Nutrient hysteresis patterns were primarily clockwise or no hysteresis. Similarities in types of C-Q relationships were investigated using Principal Component Analysis (PCA) considering effects of catchment size, land use, climate, and dominant soil type. The PCA analysis revealed that land use and air temperature were the dominant factors controlling nutrient C-Q types. Therefore, the nutrient export behaviour in streams draining Nordic mini-catchments seems to be dominantly controlled by their land use characteristics and, to a lesser extent, their climate.
  • Aaltonen, Heidi; Tuukkanen, Tapio; Palviainen, Marjo; Laurén, Annamari (Ari); Tattari, Sirkka; Piirainen, Sirpa; Mattsson, Tuija; Ojala, Anne; Launiainen, Samuli; Finér, Leena (2021)
    Understanding the anthropogenic and natural factors that affect runoff water quality is essential for proper planning of water protection and forest management, particularly in the changing climate. We measured water quality and runoff from 10 unmanaged and 20 managed forested headwater catchments (7-12,149 ha) located in Finland. We used linear mixed effect models to test whether the differences in total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) export and concentrations observed can be explained by catchment characteristics, land use, forest management, soil fertility, tree volume and hydrometeorological variables. Results show that much of variation in TOC, TN and TP concentrations and export was explained by drainage, temperature sum, peatland percentage and the proportion of arable area in the catchment. These models explained 45-63% of variation in concentrations and exports. Mean annual TOC export in unmanaged catchments was 56.4 +/- 9.6 kg ha(-1) a(-1), while in managed it was 79.3 +/- 3.3 kg ha(-1) a(-1). Same values for TN export were 1.43 +/- 0.2 kg ha(-1) a(-1) and 2.31 +/- 0.2 kg ha(-1) a(-1), while TP export was 0.053 +/- 0.009 kg ha(-1) a(-1) and 0.095 +/- 0.008 kg ha(-1) a(-1) for unmanaged and managed, respectively. Corresponding values for concentrations were: TOC 17.7 +/- 2.1 mg L-1 and 28.7 +/- 1.6 mg L-1, for TN 420 +/- 45 mu g L-1 and 825 +/- 51 mu g L-1 and TP 15.3 +/- 2.3 mu g L-1 and 35.6 +/- 3.3 mu g L-1. Overall concentrations and exports were significantly higher in managed than in unmanaged catchments. Long term temperature sum had an increasing effect on all concentrations and exports, indicating that climate warming may set new challenges to controlling nutrient loads from catchment areas.
  • Kivela, Jukka; Chen, Lin; Muurinen, Susanna; Kivijarvi, Pirjo; Hintikainen, Veikko; Helenius, Juha (2015)
    Meat and bone meal (MBM) is a by-product of the meat industry and is an important pathway for recycling of N and P. MBM contains about 8% N, 5% P, 1% K and 10% Ca. Field trials compared the effects of MBM and mineral fertilizer on yield and quality of sugar beet (2008-2009) and carrot (2010-2011) in Finland. MBM fertilisation of sugar beet grown on clay loam and sandy clay soil gave 11.4% (2008) and 19.6% (2009) lower yields than mineral fertilizers. The lower root yield in 2008 was compensated by higher extractable sugar content and lower amino-N, K and Na in root but no such compensation in root quality was detected for 2009. Mixing MBM with mineral NPK fertilizers had similar effects as MBM-alone. MBM (80 kg N ha(-1) 2010 and 60 kg N ha(-1) 2011) together with K fertilizer (Patentkali (R), 180 kg K ha(-1)) were applied for carrot to a fine sandy till soil in 2010 and sandy loam in 2011. MBM alone gave 14% lower total and marketable root yield than mineral fertilization. The lower yield was compensated by improved quality, lower NO3- content in the carrot and good storability. Adding extra fertilizer during growth or separating fertilization applications had no effect on root yield or quality. MBM performed in these cases mainly as an organic N fertilizer. The N supply from MBM is not sufficient for achieving same yields as with mineral fertilizers. The relative N efficiency of total N of MBM was 83% that of mineral fertilizers. MBM should be targeted on soils with low P status. We conclude that MBM is a reasonably competitive alternative to mineral fertilizers, and as a recycled fertilizer it is a good option for organic production.
  • Schaedig, Eric (Helsingin yliopisto, 2020)
    The Baltic Sea is a unique and delicate brackish water ecosystem with high primary productivity driven by oceanic biogeochemical cycles of oxygen, iron, silicon, nitrogen and phosphorus. Elevated anthropogenic nutrient loading into the Baltic ecosystem has resulted in a large-scale increase in destructive cyanobacterial blooms in the open Baltic Sea over the past century. The toxic cyanobacterium Nodularia spumigena is a major component of surface blooms in the open Baltic Sea and continues to bloom even after the depletion of phosphate from the surrounding waters. This phenomenon has been attributed to an ability to scavenge phosphorus from recalcitrant sources. However, the exact phosphorus species that sustain N. spumigena growth in the Baltic Sea remain largely unknown. Here, I employ a comparative genomics approach to determine the evolutionary dynamics of phosphorus scavenging in eight strains of N. spumigena and predict the range of phosphorus sources that may support their growth. Then, I test these predictions by growing six strains of N. spumigena on a number of potentially bioavailable phosphorus sources. Among the phosphorus scavenging genes identified by the genomic analysis, putative pathways for the enzymatic degradation of phytic acid, phosphite, and phosphonates were present and highly conserved in the species. Subsequent growth experiments demonstrated that the organism may grow using phytic acid and phosphite, as well as the phosphonates methylphosphonic acid, ethylphosphonic acid, and nitrilotris(methylenephosphonic acid), as sole phosphorus sources. These results indicate that N. spumigena blooms may be supported by several phosphorus sources previously not known to contribute to eutrophication in the Baltic Sea. While additional growth experiments and further research on the environmental prevalence of these compounds are necessary, the findings presented in this study expand our knowledge of how N. spumigena dominates phytoplankton blooms in a phosphorus-scarce environment and may help to inform future eutrophication mitigation efforts in the Baltic Sea region.
  • Seppälä, J.; Tamminen, T.; Kaitala, S. (Elsevier Science B.V., 1999)
    Phytoplankton nutrient limitation was studied in the Gulf of Riga during spring bloom April 1995., early summer stage June 1994., cyanobacterial bloom July 1994. and post cyanobacterial bloom August 1993.. Each year six factorial nutrient enrichment experiments were carried out in various locations in the Gulf; including outer Irbe Strait, northern Gulf and southern Gulf. The responses of natural phytoplankton communities to the nutrient additions 80 mg NH4-N ly1, 20 mg PO4-P ly1 and two levels of combined additions. were followed for 3 days using 6 l experimental units. To evaluate the nutrient limitation patterns, time series of chlorophyll a were analysed using polynomial regression models and ranking method, taking advantage of the relatively constant experimental error. Apparent nutrient depletion rates and ratios were estimated, and compared with the changes in particulate nutrient ratios. During the spring diatom bloom in 1995, ambient inorganic nutrient concentrations were still high, and thus phytoplankton biomass did not respond to additions of nutrients. Chlorophyll a specific nutrient depletion rates were low 0.01-0.12 mg Nmg chl a.y1 hy1 and 0.002-0.016 mg P mg chl a.y1 hy1. and linear over time, thus also revealing that phytoplankton was not limited by these nutrients in that time. In June 1994, there was an areal shift from N limitation in the outer Irbe Strait towards co-limitation in the southern Gulf. Later in July 1994, during the bloom of N-fixing Aphanizomenon flos-aquae, the N limitation was obvious for the whole study area. For this period chlorophyll a specific nutrient depletion rates were high 0.360.67 mg N mg chl a.y1 hy1 and 0.089-0.135 mg Pmg chl a.y1 hy1., and added nutrients were almost totally depleted during the first light period. After the collapse of cyanobacterial bloom in August 1993, the experiment carried out in the southern Gulf indicated P limitation of phytoplankton. The central Gulf was obviously co-limited, while the area between northern Gulf and outer Irbe Strait was N-limited. Our results indicate that phytoplankton in the Gulf of Riga, earlier considered strictly as P-limited, is at least until late-summer period N- or co-limited. It seems also obvious that there exists a spatial tendency in the phytoplankton limitation patterns, generally from more P- or co-limited southern Gulf towards more N-limited northern basin.
  • Sokka, L.; Antikainen, R.; Kauppi, P.E. (Inderscience Enterprises, 2004)
    Nitrogen (N) and phosphorus (P) are two nutrients contributing to several environmental problems, particularly eutrophication of surface waters. Leakages of these nutrients occur through human activity. In this study, the flows of N and P in the Finnish municipal waste system in 1952–1999 were determined and analysed using substance flow analysis (SFA). Nutrient flows in both wastewaters and solid waste peaked in 1990, after which they declined until 1994 but thereafter increased again although remaining lower than in 1990. At the end of the 1990s the wastewater and solid waste from municipalities and rural households contained ca. 7.0 kg N person–1 a–1 and 1.1 kg P person–1 a–1. Untreated wastewater contained three times more N and four times more P than solid waste. The amounts of N and P involved in recycling increased over the study period being 10% for N and 50% for P at the end of the 1990s.
  • Virkki, Leena P. (Helsingin yliopisto, 2020)
    Siilinjärvi carbonatite in the eastern Finland is an Archaean intrusion. It is mined for the phosphorus bearing apatite used in fertilizers. Saarinen open pit is a satellite mine of the main Särkijärvi open pit. Siilinjärvi carbonatite is the lowest grade apatite ore in the world being excavated and the largest industrial mineral mine in Finland with approx. 11 Mt ore mined yearly making up almost 70 percent of the industrial minerals mined in Finland. The Siilinjärvi carbonatite is a north-south trending and nearly vertical intrusion within basement gneisses. The complex consists of a continuous rock series between end members of nearly pure glimmerite and carbonatite. During the intrusion, the glimmerite-dcarbonatite has metasomatically altered the adjacent country rocks resulting a fenite halo of varying thickness. The purpose of this M. Sc. thesis was to produce a geological map and study the petrography and geochemistry of the rock types of the complex in the Saarinen area. The bedrock surface of Saarinen open pit area was mapped in detail with a GNSS receiver and data was edited with LeapFrog, ArcMap and QGIS. 24 rock samples were collected and thin sections were prepared for petrographic analysis. ICP-MS analysis was made of 20 rock samples to obtain whole rock geochemical data. Sludge sampling was carried out which produced 299 samples from 51 drill holes down to maximum 24 metres from the surface. Sludge samples were analysed with ICP-OES. Geological mapping showed that the most carbonate rich rock types of the complex are located in the middle of the complex. The different rock types of the complex are oriented along the main direction of the formation. Fenite occurs on the edge of the complex and as xenoliths within the glimmerite-carbonatite series rocks. Petrography studies showed that nearly all of the samples shared the same mineral constitution, only the modal proportions of different minerals vary. The main minerals are phlogopite, calcite, richterite and apatite. Geochemical whole rock analysis indicated that the phosphorus content of the rocks studied is highest in the rock types containing 10-50% carbonates. The trace element and REE compositions of the samples differ from average carbonatite, especially Nb, La, Ce and Y contents are lower. The geochemical analysis of sludge samples showed that the rock types are not continuous across long depths.
  • Kauppi, Katja; Rajala, Ari; Huusela, Erja; Kaseva, Janne; Ruuttunen, Pentti; Jalli, Heikki; Alakukku, Laura; Jalli, Marja (2021)
    The effect of weeds, plant diseases and insect pests on spring barley (Hordeum vulgare) and spring wheat (Triticum aestivum) grain and nutrient yield was examined. Long-term field trial data was used to assess the impact of different pests on grain yield. In the absence of pesticides, fungal diseases caused the largest annual yield-reduction in spring wheat and spring barley, 500 kg ha(-1) on average. Converting yield loss to nutrient yield loss this represented reductions of 8.1 and 9.2 kg ha(-1) in nitrogen and 1.5 and 1.6 kg ha(-1) in phosphorus, respectively. Likewise, it was estimated that weeds decrease the yield of spring barley and spring wheat for 200 kg ha(-1), which means reductions of 3.7 and 3.2 kg ha(-1) in nitrogen and 0.6 kg ha(-1) in phosphorus, respectively. For insect pests yield-reduction in spring barley and spring wheat varied between 418 and 745 kg ha(-1) respectively. However, because bird cherry-oat aphid (Rhopalosiphum padi L.) incidence data was limited, and aphids are highly variable annually, nutrient yield losses caused by insect pests were not included. Based on the current study, the management of weeds, plant diseases and insects maintain cereal crop yield and may thus decrease the environmental risks caused by unutilized nutrients.
  • Heikkinen, Janne (Helsingfors universitet, 2011)
    The ambition of the agricultural environmental programme is to reduce nutrient load, because greater part of the diffuse loading of phosphorus is caused by agriculture. A eutrophic influence of the phosphorus in water systems tends to be limited inter alia by constructed wetlands. Their main task is to allow sedimentation of eroded soil into the bottom of the wetlands. There is ambiguity on the findings of the functionality and the importance of the prevention of water loading among scientific research in Finland. The aim of this study is to examine by utilizing soil analyses what happens to the basin water eroded phosphorus in the wetland sediment and wether the sedimentary constituent of the soil be suitable for a substratum of plant production. Comparing the samples of basin soil and wetland sediments revealed that the eroded constituent of the basin soil got assorted on wetlands. The samples collected from the wetlands contained 48 % more clay than the samples collected from the basin soil. The growth of the clay concentration increased the reactive area of the sediment. In consequence, it contained 45 % more hydroxides of aluminium and iron in the samples of the sediment than the samples of the basin soil. Because of the hydroxides, the phosphorus sorption capacity was 52 % higher than in the samples of the basin soil. However, the degree of phosphorus saturation was equal in the sediment and basin soil, because the oxidized sediment contained 50 % more phosphorus extracted from hydroxides of aluminium and iron. At the time of sampling the sediment was in reduced state and the amount of its water extracable phosphorus was significantly higher compared to the oxidized sediment. Correspondingly, when the sediment became oxidized the sorption capacity for phosphorus increased significantly, therefore the phosphorus was desorbed from reduced sediment to the wetlands water. This was also proven in a pot experiment, where rye-grass that grew in the sediment suffered from a severe shortage of phosphorus. In contrast, rye-grass grown in the basin soil didn’t suffer from the deficiency of phosphorus at the same fertilization levels. After threefold extra fertilization of phosphorus, the dry matter yield, concentration of phosphorus and uptake of phosphorus on the second yield grown in sediment were equal to the results of the first yield grown in basin soil. According to the results of the pot experiment, the sediment in reduced state is weakly suitable for the substratum of plant production, because the sorption capacity of phosphorus is high. Instead, sediment suits well to be utilized in the areas wherein the soil includes plenty of easy soluble phosphorus, such as for the material of subgrade for the corral of livestock, because the sediment reduces the load of phosphorus directed to the environment.
  • de Wit, Heleen A.; Lepistö, Ahti; Marttila, Hannu; Wenng, Hannah; Bechmann, Marianne; Blicher-Mathiesen, Gitte; Eklöf, Karin; Futter, Martyn N.; Kortelainen, Pirkko; Kronvang, Brian; Kyllmar, Katarina; Rakovic, Jelena (Wiley, 2020)
    Hydrological Processes 34, 25 (2020)
    Agricultural, forestry-impacted and natural catchments are all vectors of nutrient loading in the Nordic countries. Here, we present concentrations and fluxes of total nitrogen (totN) and phosphorus (totP) from 69 Nordic headwater catchments (Denmark: 12, Finland:18, Norway:17, Sweden:22) between 2000 and 2018. Catchments span the range of Nordic climatic and environmental conditions and include natural sites and sites impacted by agricultural and forest management. Concentrations and fluxes of totN and totP were highest in agricultural catchments, intermediate in forestry-impacted and lowest in natural catchments, and were positively related %agricultural land cover and summer temperature. Summer temperature may be a proxy for terrestrial productivity, while %agricultural land cover might be a proxy for catchment nutrient inputs. A regional trend analysis showed significant declines in N concentrations and export across agricultural (−15 μg totN L−1 year−1) and natural (−0.4 μg NO3-N L−1 year−1) catchments, but individual sites displayed few long-term trends in concentrations (totN: 22%, totP: 25%) or export (totN: 6%, totP: 9%). Forestry-impacted sites had a significant decline in totP (−0.1 μg P L−1 year−1). A small but significant increase in totP fluxes (+0.4 kg P km−2 year−1) from agricultural catchments was found, and countries showed contrasting patterns. Trends in annual concentrations and fluxes of totP and totN could not be explained in a straightforward way by changes in runoff or climate. Explanations for the totN decline include national mitigation measures in agriculture international policy to reduced air pollution and, possibly, large-scale increases in forest growth. Mitigation to reduce phosphorus appears to be more challenging than for nitrogen. If the green shift entails intensification of agricultural and forest production, new challenges for protection of water quality will emerge possible exacerbated by climate change. Further analysis of headwater totN and totP export should include seasonal trends, aquatic nutrient species and a focus on catchment nutrient inputs.
  • Nieminen, Mika; Sarkkola, Sakari; Hasselquist, Eliza Maher; Sallantaus, Tapani (Kluwer Academic Publishers, 2021)
    Water, Air, & Soil Pollution 232 (2021), 371
    Contradictory results for the long-term evolution of nitrogen and phosphorus concentrations in waters discharging from drained peatland forests need reconciliation. We gathered long-term (10–29 years) water quality data from 29 forested catchments, 18 forestry-drained and 11 undrained peatlands. Trend analysis of the nitrogen and phosphorus concentration data indicated variable trends from clearly decreasing to considerably increasing temporal trends. While the variations in phosphorus concentration trends over time did not correlate with any of our explanatory factors, trends in nitrogen concentrations correlated positively with tree stand volume in the catchments and temperature sum. A positive correlation of increasing nitrogen concentrations with temperature sum raises concerns of the future evolution of nitrogen dynamics under a warming climate. Furthermore, the correlation with tree stand volume is troublesome due to the generally accepted policy to tackle the climate crisis by enhancing tree growth. However, future research is still needed to assess which are the actual processes related to stand volume and temperature sum that contribute to increasing TN concentrations.
  • Poudel, Hari (Helsingin yliopisto, 2021)
    Meat bone meal contains considerable amount of nutrients (on average 8% N, 5% P, 1% K and 10 % Ca). Therefore, it can be used as fertilizer for different crops. Whether meat bone meal (LL) can achieve similar effect in increasing the grain yield and grain quality of oat as meat bone meal mixed with biotite (LB), meat bone meal mixed with blast furnace slag (LB) and meat bone meal mixed with lime (LK) or not were analyzed in this study. Two field experiments: one in Viikki experimental farm, and other in suitia experimental farm of the University of Helsinki were carried out in the summer of 2005. LL, LB, LM, and LK were applied in three N levels: 60, 90 and 120 kg N ha-1 in Viikki and Suitia experimental farms. In both experimental farm, oat grain yield, oat grain test weight, and oat 1000-grain weight did not differ between the fertilizer types. In Suitia experimental farm, oat grain yield and 1000-grain weight increased with increasing the N-levels but not oat test weight whereas in Vikki experimental farm, oat grain yield, oat test weight, and oat 1000-grain weight did not increase with increasing the N levels. Since the N/P ratio of meat bone meal is considerably narrower than the normal nutrient uptake ratio of cereals, hence, if it is applied to meet the N demand of crops then P in soil would be surplus. Therefore, due to the P residual effect, it is recommended not to use meat bone meal in the following year or even for the whole crop rotation but recommended to grow green manure crops as for nitrogen resources to organic farms after using meat bone meal. Since K content of meat bone meal is rather low therefore, to balance the nutrient contents in meat bone meal, some of the most viable alternatives for additional K such as biotite, vinasse, potassium sulphate could be added to meat bone meal to achieve meat bone meal-NPK contents more optimal for crops.
  • Makkonen, Ulla; Saarnio, Karri; Ruoho-Airola, Tuija; Hakola, Hannele (Ilmatieteen laitos, 2016)
    Raportteja - Rapporter - Reports 2016:2
    Tiivistelmä Itämeren pahimpana ongelmana pidetään typpi- ja fosforikuormituksen aiheuttamaa rehevöitymistä. Typpeä ja fosforia joutuu Itämereen paitsi valumana rantavaltioista myös merkittävissä määrin ilman kautta. Ilmaperäisen typpilaskeuman määrää ja sen kehitystä on selvitetty mittauksin ja mallinnuksen avulla 1980-luvulta lähtien, mutta ilmaperäistä fosforikuormaa Itämereen on mitattu vain sateen mukana laskeutuvan märkälaskeuman osalta muutamilla asemilla. Hiukkasiin sitoutuneesta kuivalaskeumasta ei mittaustietoa ole julkaistu lainkaan, eikä Itämeren ympärysvaltioilla ole käytettävissään menetelmää ilmaperäisen fosforikuorman hiukkasosuuden seuraamiseksi. Tässä työssä kehitettiin ja testattiin menetelmät ilmakehästä sadeveden mukana tulevan sekä ilmakehän hiukkasiin sitoutuneen fosfaatin sekä kokonaisfosforin määrittämiseksi. Menetelmäkehitys sisälsi näytteenkeruumenetelmät, näytteen esikäsittelymenetelmät sekä kemialliset analyysimenetelmät. Menetelmiä testattiin Utön saarella Saaristomeren ulkolaidalla vuosien 2013–2015 aikana. Utön saarella toimii Ilmatieteen laitoksen mittausasema, jonka mittaustulokset edustavat ilmanlaadun tausta-arvoja pohjoisella Itämerellä. Testattuina fosforin ja fosfaatin kuiva- ja märkälaskeuman näytteenkeruumenetelminä toimivat olemassa olevat ja laajasti käyttöönotetut EMEP-protokolliin perustuvat menetelmät. Näytteiden kokonaisfosforipitoisuuden määritysmenetelmään sovellettiin olemassa olevaa ISO-standardiin perustuvaa spektrometristä menetelmää. Vesiliukoisen fosfaatin pitoisuuden määrittämiseen hyödynnettiin käytössä olevaa ISO-standardiin perustuvaa ionikromatografista menetelmää, jota laajennettiin sisältämään fosfaatin määritys muiden epäorgaanisten ionien kanssa samassa analyysissä. Havaittiin, että sekä märkä- että kuivalaskeumanäytteiden sisältämät kokonaisfosfori- ja fosfaattipitoisuudet olivat erittäin alhaisia, usein pitoisuudet olivat lähellä analyysimenetelmien määritysrajoja tai niiden alle. Kuitenkin mittausjakson ajalta saatiin riittävä määrä määritystuloksia, joiden avulla voidaan laskea aiempaa luotettavampi arvio vuotuisesta ilmaperäisestä fosforikuormituksesta Itämereen. Työssä tutkittiin Utön saaren mittausasemalla suoritetun intensiivikampanjan aikana mahdollisuutta määrittää hiukkasissa olevan fosfaatin pitoisuutta jatkuvatoimisella ionikromatografilla. Menetelmän herkkyys osoittautui kuitenkin riittämättömäksi ilmakehän hiukkasten fosfaattipitoisuuden määrittämiseen. Käytetyt menetelmät on esitelty tässä raportissa siten, että menetelmät voidaan ottaa käyttöön muillakin mittausasemilla ja laboratorioissa sadeveden ja ilmakehän hiukkasten sisältämien fosfaatin ja kokonaisfosforin pitoisuuksien määrittämiseksi, ja siten ilmaperäisen fosforin kuormitusta voidaan arvioida luotettavammin ja laajemmin Itämeren alueella. Abstract Eutrophication caused by nitrogen and phosphorus load is generally thought as the most severe problem of the Baltic Sea. Nitrogen and phosphorus end up in the Baltic Sea not only by run-off from the coastal countries of the Baltic Sea but to an important extent also from the atmosphere. The amount of atmospheric nitrogen load and its development have been determined using measurements and models since the 1980’s. The atmospheric phosphorus load to the Baltic Sea has been measured earlier only from the wet deposition from the collected rain water samples from a few sites around the Baltic Sea; no published data exists about the particle bound dry deposition of phosphorus. The coastal countries of the Baltic Sea haven’t got any method in use to measure the particle bound phosphorus deposition. In this work, methods for determining the concentrations of phosphate and total phosphorus in atmospheric precipitation and particulate matter were developed and tested. The method development included the sampling, sample pre-treatment, and chemical analysis techniques. The methods were tested onsite on the Utö Island in the outskirts of the Archipelago Sea during the years 2013–2015. The monitoring station on the Utö Island is operated by the Finnish Meteorological Institute. The measurements on the station represent the background air quality of the northern Baltic Sea area. The existing and widely used sampling methods based on the EMEP protocols were tested for the sampling of dry and wet deposition of phosphorus and phosphate. A spectrometric method based on an ISO standard was applied for determination of the total phosphorus concentration of the samples. For the determination of dissolved phosphate, an ion chromatographic method based on an ISO standard was extended to include the analysis of phosphate with the main inorganic ions. It was discovered that the concentrations of total phosphorus and dissolved phosphate in the dry and wet deposition samples were very low; the concentrations were often close to the determination limits of the used analytical methods or even below those. Nevertheless, a sufficiency of samples were determined to be able to estimate the yearly atmospheric phosphorus load to the Baltic Sea more reliably than earlier. In addition, feasibility of measuring the concentration of particle-bound phosphate using a semi-continuous ion chromatograph was tested in the Utö Island during an intensive campaign. However, the sensitivity of the analyser was not sufficient to measure the low atmospheric concentrations of phosphate. The used methods are presented in this report so that they can be taken into use in other sampling sites and laboratories to determine the concentrations of phosphate and total phosphorus in the precipitation and in the atmospheric particulate matter. Thus, more reliable estimates of the atmospheric phosphorus load to the Baltic Sea could be calculated more widely.
  • Westerling, Kim (Helsingfors universitet, 2011)
    In Finland most of the accumulated phosphorus in the agricultural soils is underutilized and at the same time excess phosphorus in soil is susceptible to leaching. Arbuscular mycorrhiza (AM) has the potential to promote plant phosphorus nutrition and growth, and reduce nutrient leaching. The aim of this study was to investigate the effect of mycorrhizal symbiosis on plant growth and phosphorus nutrition with three different fertilization management practices. The influence of fertilization management history on field AMF population was also studied. To relate the impact on AM to impacts on other soil quality aspects, the effect of the fertilization rates on crop growth and indicators of soil functioning was evaluated. Long term field experiments established in 1965-66 on three sites in Northern Sweden were utilized. Six years’ rotation either with five grass years and a barley year or barley monoculture was treated with recommended (NPK) and double the recommended (2NPK) rate of mineral fertilisation or with farmyard manure (FYM) with a nutrient amount corresponding to the NPK –treatment for 32 years. The effect of three long term practices on the potential AM contribution to crop phosphorus nutrition and growth was studied in a bioassay. To study the impact of longterm management practices on functional properties of AMF, the sterilised soil from the field plots of NPK and FYM treatments was re- and cross-inoculated (5 v-%) with untreated field soil from each of the same treatments. Crop yields were measured in the field and field soil quality was assessed. Benefit from AM in terms of crop phosphorus nutrition and growth was greatest when manure was applied while there were no differences among the mineral fertiliser treatments. There were no statistically significant differences in the bioassay with re- and cross-inoculations. Grass and barley yields were highest when mineral NPK fertiliser was applied at double the recommended rate. Crop performed equally well or better in terms of yield with manure compared to a corresponding nutrient amount in mineral fertilizers. Manure applications seemed to increase soil carbon and nitrogen contents relative to the recommended amount of NPK, yet keeping the plant-available phosphorus concentration liable for leaching at a similarly low level. Thus, enhanced recycling of nutrients through use of farmyard manure to replace mineral NPK fertilisation favoured reliance on AM in phosphorus nutrition of crops with no trade-off in yields, simultaneously enhancing soil quality.
  • Laurén, Ari; Palviainen, Marjo; Page, Susan; Evans, Chris; Urzainki, Inaki; Hökkä, Hannu (2021)
    Responsible management of Acacia plantations requires an improved understanding of trade-offs between maintaining stand production whilst reducing environmental impacts. Intensive drainage and the resulting low water tables (WT) increase carbon emissions, peat subsidence, fire risk and nutrient export to water courses, whilst increasing nutrient availability for plant uptake from peat mineralization. In the plantations, hydrology, stand growth, carbon and nutrient balance, and peat subsidence are connected forming a complex dynamic system, which can be thoroughly understood by dynamic process models. We developed the Plantation Simulator to describe the effect of drainage, silviculture, fertilization, and weed control on the above-mentioned processes and to find production schemes that are environmentally and economically viable. The model successfully predicted measured peat subsidence, which was used as a proxy for stand total mass balance. Computed nutrient balances indicated that the main growth-limiting factor was phosphorus (P) supply, and the P balance was affected by site index, mortality rate and WT. In a scenario assessment, where WT was raised from -0.80 m to -0.40 m the subsidence rate decreased from 4.4 to 3.3 cm yr(-1), and carbon loss from 17 to 9 Mg ha(-1) yr(-1). P balance shifted from marginally positive to negative suggesting that additional P fertilization is needed to maintain stand productivity as a trade-off for reducing C emissions.
  • Mustonen, Arja (Helsingfors universitet, 2014)
    In Finland 90% of all farmers and 95% of cultivated land are committed to the environmental support program of agriculture. One of the goals of this program is to reduce phosphorus (P) runoff from fields to the water system by limiting the amount of P used in cultivation process. Experiments on P rates allowed in environmental support program and practices of P fertilization were conducted at two sites on ley during 2003-2011. The research aimed to define the effects of annual fertilization, incorporated fertilization and the use of liquid manures on ley yield and P status of the soil. Earlier studies have shown that more water soluble P runs off from leys than from cereal fields and that reserved P hasn’t been sufficient for the whole ley rotation. The experiment consisted of seven different fertilization treatments in which phosphorus treatments were done as incorporate fertilization or annual fertilization. Low or high-release mineral fertilizer was used for incorporate fertilization and either mineral fertilizer or at first mineral fertilizer and liquid manures in next rotation for annual fertilization on the surface. P given as liquid manure was used by three members of the experiment group. The experiment included cultivating ley for seven years and cereal forage for two years. The control group used no P fertilization. P given in fertilization treatments had no effect on ley yields compared with control treatment. Negative P balance in all treatments caused the P rate in ploughed layer of the soil to decrease, however the P levels of surface layer fluctuated greatly regardless of the way P treatments were done. The study indicated that using liquid manures for fertilizing ley cultivations does not pose any greater threat to the environment than mineral fertilizers. However, balanced fertilization, sufficient nitrogen and reducing nitrogen loss of liquid manures are required in order to achieve high yields. The results also indicate that it should be made possible to raise the amount of P fertilization of highly productive leys closer to the zero level of the nutrient balance so that productivity of the soil measured by acid ammonium acetate (PAC) would be preserved. Depending on the other qualities of the soil, this can be done when PAC has reached the value nearby 10 mg l-1. More information on controlling P of the surface soil by means of cultivation management is needed.
  • Johannesdottir, Solveig L.; Kärrman, Erik; Barquet, Karina; Koskiaho, Jari; Olsson, Olle; Giełczewski, Marek (Elsevier, 2021)
    Cleaner Environmental Systems 2: 100030
    Sustainability assessments can be a powerful tool in decision-making regarding technical innovations. In this study, a sustainability assessment of technical systems for recovering nutrients and carbon from domestic wastewater is presented. Multi-criteria analysis was used to calculate a sustainability score of three different technical systems compared to a baseline in two case-studies: the Fyriså river catchment in Sweden and the Słupia river catchment in Poland. Two participatory workshops with local stakeholders were held in each case-study, the first to co-develop the system alternatives and sustainability criteria and the second to collect stakeholder weighting of the criteria. Although the systems assessed in both case studies were similar, the resulting sustainability scores were different. In Fyris, although the differences in scores was small, the preferred alternative was introduction of source-separation followed by a large redesign of the treatment and phosphorus extraction from incinerated sludge was the least sustainable alternative. For the Słupia systems the scores varied more, and the preferred system was a large redesign of the wastewater treatment followed by ammonia stripping of the reject water and the source-separation alternative received the lowest score. In both case-studies, the more costly system received highest sustainability score indicating the large potential benefits of enhancing resource recovery from domestic wastewater. Stakeholders did not prioritize technical aspects over the other sustainability criteria, yet most of research on resource recovery interventions is focused on technical performance.