| 1. |
- Abubaker, Jamal, et al.
(författare)
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Nitrous Oxide Production from Soils Amended with Biogas Residues and Cattle Slurry
- 2013
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 42, s. 1046-1058
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Tidskriftsartikel (refereegranskat)abstract
- The amount of residues generated from biogas production has increased dramatically due to the worldwide interest in renewable energy. A common way to handle the residues is to use them as fertilizers in crop production. Application of biogas residues to agricultural soils may be accompanied with environmental risks, such as increased N2O emission. In 24-d laboratory experiments, N2O dynamics and total production were studied in arable soils (sandy, clay, and organic) amended with one of two types of anaerobically digested biogas residues (BR-A and BR-B) generated from urban and agricultural waste and nondigested cattle slurry (CS) applied at rates corresponding to 70 kg NH4+-N ha(-1). Total N2O-N losses from the sandy soil were higher after amendment with BR-B (0.32 g N2O-N m(-2)) than BR-A or CS (0.02 and 0.18 g N2O-N m(-2), respectively). In the clay soil, N2O-N losses were very low for CS (0.02 g N2O-N m(-2)) but higher for BR-A and BR-B (0.25 and 0.15 g N2O-N m(-2), respectively). In the organic soil, CS gave higher total N2O-N losses (0.31 g N2O-N m(-2)) than BR-A or BR-B (0.09 and 0.08 g N2O-N m(-2), respectively). Emission peaks differed considerably between soils, occurring on Day 1 in the organic soil and on Days 11 to 15 in the sand, whereas in the clay the peak varied markedly (Days 1, 6, and 13) depending on residue type. In all treatments, NH4+ concentration decreased with time, and NO3- concentration increased. Potential ammonium oxidation and potential denitrification activity increased significantly in the amended sandy soil but not in the organic soil and only in the clay amended with CS. The results showed that fertilization with BR can increase N2O emissions and that the size is dependent on the total N and organic C content of the slurry and on soil type. In conclusion, the two types of BR and the CS are not interchangeable regarding their effects on N2O production in different soils, and, hence, matching fertilizer type to soil type could reduce N2O emissions. For instance, it could be advisable to avoid fertilization of organic soils with CS containing high amounts or organic C and instead use BR. In clay soil, however, the risk of N2O emissions could be lowered by choosing a CS.
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| 2. |
- Ahlgren, Joakim, et al.
(författare)
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Barium as a Potential Indicator of Phosphorus in Agricultural Runoff
- 2012
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 41, s. 208-216
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Tidskriftsartikel (refereegranskat)abstract
- In many catchments, anthropogenic input of contaminants, and in particular phosphorus (P), into surface water is a mixture of agricultural and sewage runoff. Knowledge about the relative contribution from each of these sources is vital for mitigation of major environmental problems such as eutrophication. In this study, we investigated whether the distribution of trace elements in surface waters can be used to trace the contamination source. Water from three groups of streams was investigated: streams influenced only by agricultural runoff, streams influenced mainly by sewage runoff, and reference streams. Samples were collected at different flow regimes and times of year and analyzed for 62 elements using ICP-MS. Our results show that there are significant differences between the anthropogenic sources affecting the streams in terms of total element composition and individual elements, indicating that the method has the potential to trace anthropogenic impact on surface waters. The elements that show significant differences between sources are strontium (p < 0.001), calcium (p < 0.004), potassium (p < 0.001), magnesium (p < 0.001), boron (p < 0.001), rhodium (p = 0.001), and barium (p < 0.001). According to this study, barium shows the greatest potential as a tracer for an individual source of anthropogenic input to surface waters. We observed a strong relationship between barium and total P in the investigated samples (R-2 = 0.78), which could potentially be used to apportion anthropogenic sources of P and thereby facilitate targeting of mitigation practices.
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| 3. |
- Ahlgren, Joakim, et al.
(författare)
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Sediment Phosphorus Extractants for Phosphorus-31 Nuclear Magnetic Resonance Analysis : A Quantitative Evaluation
- 2007
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Ingår i: Journal of Environmental Quality. - Uppsala Univ, Dept Phys & Analyt Chem, S-75124 Uppsala, Sweden. Univ So Denmark, Inst Biol, DK-5230 Odense M, Denmark. Uppsala Univ, Dept Biochem & Organ Chem, S-75124 Uppsala, Sweden. Uppsala Univ, Dept Ecol & Evolut, S-75123 Uppsala, Sweden. : Wiley. - 0047-2425 .- 1537-2537. ; 36:3, s. 892-898
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Tidskriftsartikel (refereegranskat)abstract
- The influence of pre-extractant, extractant, and post-extractant on total extracted amounts of P and organic P compound groups measured with 31P nuclear magnetic resonance (31P-NMR) in lacustrine sediment was examined. The main extractants investigated were sodium hydroxide (NaOH) and sodium hydroxide ethylenediaminetetraacetic acid (NaOH-EDTA) with bicarbonate buffered dithionite (BD) or EDTA as pre-extractants. Post extractions were conducted using either NaOH or NaOH-EDTA, depending on the main extractant. Results showed that the most efficient combination of extractants for total P yield was NaOH with EDTA as pre-extractant, yielding almost 50% more than the second best procedure. The P compound groups varying the most between the different extraction procedures were polyphosphates and pyrophosphates. NaOH with BD as pre-extractant was the most efficient combination for these compound groups.
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| 4. |
- Alsanius, Beatrix
(författare)
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Simultaneous Removal of Nitrate and Sulfate from Greenhouse Wastewater by Constructed Wetlands
- 2013
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 42, s. 1256-1266
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the effectiveness of C-enriched subsurfaceflow constructed wetlands in reducing high concentrations of nitrate (NO 3 -) and sulfate (SO 4 2-) in greenhouse wastewaters. Constructed wetlands were filled with pozzolana, planted with common cattail (Typha latifolia), and supplemented as follows: (i) constructed wetland with sucrose (CW+ S), wetland units with 2 g L-1 of sucrose solution from week 1 to 28; (ii) constructed wetland with compost (CW+ C), wetland units supplemented with a reactive mixture of compost and sawdust; (iii) constructed wetland with compost and no sucrose (CW+ CNS) from week 1 to 18, and constructed wetland with compost and sucrose (CW+ CS) at 2 g L-1 from week 19 to 28; and (iv) constructed wetland (CW). During 28 wk, the wetlands received a typical reconstituted greenhouse wastewater containing 500 mg L-1 SO(4)(2-)and 300 mg L-1 NO3-. In CW+ S, CW+ C, and CW+ CS, appropriate C: N ratio (7: 3.4) and redox potential (-53 to 39 mV) for denitrification resulted in 95 to 99% NO3- removal. Carbon source was not a limiting factor for denitrification in C-enriched constructed wetlands. In CW+ S and CW+ CS, the dissolved organic carbon (DOC)/SO(4)(2-)ratios of 0.36 and 0.28 resulted in high sulfate-reducing bacteria (SRB) counts and high SO 4 2-removal (98%), whereas low activities were observed at DOC/SO(4)(2-)ratios of 0.02 (CW) to 0.11 (CW+ C, CW+ CNS). On week 19, when organic C content was increased by sucrose addition in CW+ CS, SRB counts increased from 2.80 to 5.11 log[CFU+ 1] mL(-1), resulting in a level similar to the one measured in CW+ S (4.69 log[CFU+ 1] mL(-1)). Consequently, high sulfate reduction occurred after denitrification, suggesting that low DOC (38-54 mg L-1) was the limiting factor. In CW, DOC concentration (9-10 mg L-1) was too low to sustain efficient denitrification and, therefore, sulfate reduction. Furthermore, the high concentration of dissolved sulfides observed in CW+ S and CW+ CS treated waters were eliminated by adding FeCl3
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| 5. |
- Aronsson, Andreas, et al.
(författare)
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Biological effects of Wood Ash Application.
- 2004
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Ingår i: Journal of Environmental Quality. - 0047-2425 .- 1537-2537. ; 33:5, s. 1595-1605
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish National Board of Forestry recommends recycling of wood ash for two main reasons: 1) to avoid depletion of essential soil nutrients, and 2) to reduce the harmful effects of acidification of surface waters. There is no doubt that recycling of wood ash to boreal forests will become a major industry in the near future. Much research is conducted regarding the effects of wood ash application on forest growth. Present studies show that, generally speaking, forest growth can be increased on wood ash-ameliorated peatland rich in nitrogen. On mineral soils, however, no change or even decreased growth has been reported. The effects on ground vegetation are not very clear, as well as the effects on fungi, soil microbes and soil decomposing animals. The discrepancies between different studies are for the most part explained by abiotic factors such as variation in fertility among sites, different degrees of stabilization and wood ash dosage used, and different time scales among different studies. The lack of knowledge in the field of aquatic ecosystems and their response to ash application is an important issue for future research. The few studies conducted have mainly considered changes in water chemistry. The biotoxic effects of ash application can roughly be divided into two categories: primary and secondary. Among the primary effects is toxicity deriving from compounds in the wood ash and cadmium is probably the worst among these. The secondary effects of wood ash are generally due to its alkaline capacity and a release of ions into the soil and soil water, and finally, watercourses and lakes. The present review aims to summarize current knowledge in the topic of wood ash application to boreal forest and aquatic ecosystems, and the different effects derived from these actions. ABBREVIATIONS: WAA, Wood ash application; MT, metric tonnes
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| 6. |
- Aronsson, Andreas, et al.
(författare)
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Biological effects of wood ash application to forest and aquatic ecosystems
- 2004
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 33:5, s. 1595-1605
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Forskningsöversikt (refereegranskat)abstract
- The present review aims to summarize current knowledge in the topic of wood ash application to boreal forest and aquatic ecosystems, and the different effects derived from these actions. Much research has been conducted regarding the effects of wood ash application on forest growth. Present studies show that, generally speaking, forest growth can be increased on wood ash–ameliorated peatland rich in nitrogen. On mineral soils, however, no change or even decreased growth have been reported. The effects on ground vegetation are not very clear, as well as the effects on fungi, soil microbes, and soil‐decomposing animals. The discrepancies between different studies are for the most part explained by abiotic factors such as variation in fertility among sites, different degrees of stabilization, and wood ash dosage used, and different time scales among different studies. The lack of knowledge in the field of aquatic ecosystems and their response to ash application is an important issue for future research. The few studies conducted have mainly considered changes in water chemistry. The biotoxic effects of ash application can roughly be divided into two categories: primary and secondary. Among the primary effects is toxicity deriving from compounds in the wood ash and cadmium is probably the worst among these. The secondary effects of wood ash are generally due to its alkaline capacity and a release of ions into the soil and soil water, and finally, watercourses and lakes. Given current knowledge, we would recommend site‐ and wood ash–specific application practices, rather than broad and general guidelines for wood ash application to forests.
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| 7. |
- Bergfur, Jenny, et al.
(författare)
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The Tarland Catchment Initiative and Its Effect on Stream Water Quality and Macroinvertebrate Indices
- 2012
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Ingår i: Journal of Environmental Quality. - : American society of Agronomy, Inc. - 0047-2425 .- 1537-2537. ; 41:2, s. 314-321
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Tidskriftsartikel (refereegranskat)abstract
- The Tarland Catchment Initiative is a partnership venture between researchers, land managers, regulators, and the local community. Its aims are to improve water quality, promote biodiversity, and increase awareness of catchment management. In this study, the effects of buffer strip installations and remediation of a large septic tank effluent were appraised by water physico-chemistry (suspended solids, NO3, NH4, soluble reactive P) and stream macroinvertebrate indices used by the Scottish Environmental Protection Agency. It was done during before and after interventions over an 8-yr period using a paired catchment approach. Because macroinvertebrate indices were previously shown to respond negatively to suspended solid concentrations in the study area, the installation of buffer strips along the headwaters was expected to improve macroinvertebrate scores. Although water quality (soluble reactive P, NH4) improved downstream of the septic tank effluent after remediation, there was no detectable change in macroinvertebrate scores. Buffer strip installations in the headwaters had no measurable effects (beyond possible weak trends) on water quality or macroinvertebrate scores. Either the buffer strips have so far been ineffective or ineffectiveness of assessment methods and sampling frequency and time lags in recovery prevent us detecting reliable effects. To explain and appreciate these constraints on measuring stream recovery, continuous capacity building with land managers and other stakeholders is essential; otherwise, the feasibility of undertaking sufficient management interventions is likely to be compromised and projects deemed unsuccessful.
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| 8. |
- Bergström, Lars
(författare)
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Agricultural Water Quality in Cold Climates: Processes, Drivers, Management Options, and Research Needs
- 2019
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 48, s. 792-802
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Tidskriftsartikel (refereegranskat)abstract
- Cold agricultural regions are important sites of global food production. This has contributed to widespread water quality degradation influenced by processes and hydrologic pathways that differ from warm region analogues. In cold regions, snowmelt is often a dominant period of nutrient loss. Freeze-thaw processes contribute to nutrient mobilization. Frozen ground can limit infiltration and interaction with soils, and minimal nutrient uptake during the nongrowing season may govern nutrient export from agricultural catchments. This paper reviews agronomic, biogeochemical, and hydrological characteristics of cold agricultural regions and synthesizes findings of 23 studies that are published in this special section, which provide new insights into nutrient cycling and hydrochemical processes, model developments, and the efficacy of different potentially beneficial management practices (BMPs) across varied cold regions. Growing evidence suggests the need to redefine optimum soil phosphorus levels and input regimes in cold regions to allow achievement of water quality targets while still supporting strong agricultural productivity. Practices should be considered through a regional and site-specific lens, due to potential interactions between climate, hydrology, vegetation, and soils, which influence the efficacy of nutrient, crop, water, and riparian buffer management. This leads to differing suitability of BMPs across varied cold agricultural regions. We propose a systematic approach ("CUPCAKE"), to achieve water quality objectives in variable and changing climates, which combines nutrient transport process Conceptualization, Understanding BMP functions, Predicting effects of variability and change, Consideration of producer input and agronomic and environmental tradeoffs, practice Adaptation, Knowledge mobilization, and Evaluation of water quality improvement.
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| 9. |
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| 10. |
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