| 1. |
- 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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| 2. |
- Bergström, Lars, et al.
(författare)
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Turnover and Losses of Phosphorus in Swedish Agricultural Soils: Long-Term Changes, Leaching Trends, and Mitigation Measures
- 2015
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 44, s. 512-523
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Tidskriftsartikel (refereegranskat)abstract
- Transport of phosphorus (P) from agricultural fields to water bodies deteriorates water quality and causes eutrophication. To reduce P losses and optimize P use efficiency by crops, better knowledge is needed of P turnover in soil and the efficiency of best management practices (BMPs). In this review, we examined these issues using results from 10 Swedish long-term soil fertility trials and various studies on subsurface losses of P. The fertility trials are more than 50 years old and consist of two cropping systems with farmyard manure and mineral fertilizer. One major finding was that replacement of P removed by crops with fertilizer P was not sufficient to maintain soil P concentrations, determined with acid ammonium lactate extraction. The BMPs for reducing P leaching losses reviewed here included catch crops, constructed wetlands, structure liming of clay soils, and various manure application strategies. None of the eight catch crops tested reduced P leaching significantly, whereas total P loads were reduced by 36% by wetland installation, by 39 to 55% by structure liming (tested at two sites), and by 50% by incorporation of pig slurry into a clay soil instead of surface application. Trend analysis of P monitoring data since the 1980s for a number of small Swedish catchments in which various BMPs have been implemented showed no clear pattern, and both upward and downward trends were observed. However, other factors, such as weather conditions and soil type, have profound effects on P losses, which can mask the effects of BMPs.
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| 3. |
- Bieroza, Magdalena, et al.
(författare)
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Hydrologic Extremes and Legacy Sources Can Override Efforts to Mitigate Nutrient and Sediment Losses at the Catchment Scale
- 2019
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Ingår i: Journal of Environmental Quality. - : AMER SOC AGRONOMY. - 0047-2425 .- 1537-2537. ; 48:5, s. 1314-1324
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Tidskriftsartikel (refereegranskat)abstract
- Combating eutrophication requires changes in land and water management in agricultural catchments and implementation of mitigation measures to reduce phosphorus (P), nitrogen (N) and suspended sediment (SS) losses. To date, such mitigation measures have been built in many agricultural catchments, but there is a lack of studies evaluating their effectiveness. Here we evaluated the effectiveness of mitigation measures in a clay soildominated headwater catchment by combining the evaluation of long-term and high-frequency data with punctual measurements upstream and downstream of three mitigation measures: limefilter drains, a two-stage ditch, and a sedimentation pond. Long-term hydrochemical data at the catchment outlet showed a significant decrease in P (-15%) and SS (-28%) and an increase in nitrate nitrogen (NO3-N, + 13%) concentrations. Highfrequency (hourly) measurements with a wet-chemistry analyzer (total and reactive P) and optical sensor (NO3-N and SS) showed that the catchment is an abundant source of nutrients and sediments and that their transport is exacerbated by prolonged drought and resuspension of stream sediments during storm events. Lime-filter drains showed a decrease in SS by 76% and total P by 80% and an increase in NO3-N by 45% compared with traditional drains, potentially indicating pollution swapping. The effectiveness of two-stage ditch and sedimentation pond was less evident and depended on the prevalent hydrometeorological conditions that drove the resuspension of bed sediments and associated sediment-bound P transport. These results suggest that increased frequency of prolonged drought due to changing weather patterns and resuspension of SS and sediment-bound P during storm events can override the generally positive effect of mitigation measures.
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| 4. |
- Blombäck, Karin, et al.
(författare)
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Applicability of Models to Predict Phosphorus Losses in Drained Fields: A Review
- 2015
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 44, s. 614-628
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Tidskriftsartikel (refereegranskat)abstract
- Most phosphorus (P) modeling studies of water quality have focused on surface runoff loses. However, a growing number of experimental studies have shown that P losses can occur in drainage water from artificially drained fields. In this review, we assess the applicability of nine models to predict this type of P loss. A model of P movement in artificially drained systems will likely need to account for the partitioning of water and P into runoff, macropore flow, and matrix flow. Within the soil profile, sorption and desorption of dissolved P and filtering of particulate P will be important. Eight models are reviewed (ADAPT, APEX, DRAINMOD, HSPF, HYDRUS, ICECREAMDB, PLEASE, and SWAT) along with P Indexes. Few of the models are designed to address P loss in drainage waters. Although the SWAT model has been used extensively for modeling P loss in runoff and includes tile drain flow, P losses are not simulated in tile drain flow. ADAPT, HSPF, and most P Indexes do not simulate flow to tiles or drains. DRAINMOD simulates drains but does not simulate P. The ICECREAMDB model from Sweden is an exception in that it is designed specifically for P losses in drainage water. This model seems to be a promising, parsimonious approach in simulating critical processes, but it needs to be tested. Field experiments using a nested, paired research design are needed to improve P models for artificially drained fields. Regardless of the model used, it is imperative that uncertainty in model predictions be assessed.
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| 5. |
- Boye, Kristin, et al.
(författare)
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Long-term Data from the Swedish National Environmental Monitoring Program of Pesticides in Surface Waters
- 2019
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 48, s. 1109-1119
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Tidskriftsartikel (refereegranskat)abstract
- Environmental monitoring is essential for assessing the impact of human activities on the environment. Monitoring data are used to ascertain that environmental standards are met, to inform policy making, to determine trends, and to provide parameterization data for prediction models. The design of monitoring programs depends on what is being monitored, for what purpose, and available resources. Here we describe the strategy and design of the Swedish environmental monitoring program for chemical pesticides in surface waters and provide data generated within this program since 2002 (www.slu.se/en/pesticide_monitoring). We include examples of how the data can be used for toxicity assessments, trend analyses, and comparison between sampling strategies. Our goal is to increase awareness of this dataset and provide detailed information about the data so that it may be incorporated into meta-analytical research, comparison studies, model validation, and other scientific efforts.
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| 6. |
- Campbell, Colin
(författare)
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Long-term Impact of Sewage Sludge Application on Rhizobium leguminosarum biovar trifolii: An Evaluation Using Meta-Analysis
- 2016
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 45, s. 1572-1587
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Tidskriftsartikel (refereegranskat)abstract
- The Long-Term Sludge Experiment (LTSE) began in 1994 at nine UK field sites as part of continuing research into the effects of sludge-borne heavy metals on soil fertility. The long-term effects of Zn, Cu, and Cd on the most probable numbers of cells (MPN) of Rhizobium leguminosarum biovar trifolii were monitored for 8 yr in sludge-amended soils. To assess the statutory limits set by the UK Sludge (Use in Agriculture) Regulations, the experimental data were reviewed using statistical methods of meta-analysis. Previous LTSE studies have focused predominantly on statistical significance rather than effect size, whereas meta-analysis focuses on the magnitude and direction of an effect, i.e., the practical significance rather than its statistical significance. Results showed Zn to be the most toxic element causing an overall significant decrease in Rhizobium MPN of -26.6% during the LTSE. The effect of Cu showed no significant effect on Rhizobium MPN at concentrations below the UK limits, although a -5% decrease in Rhizobium MPN was observed in soils where total Cu ranged from 100 to <135 mg kg(-1). Overall, there was nothing to indicate that Cd had a significant effect on Rhizobium MPN below the current UK statutory limit. In summary, the UK statutory limit for Zn appears to be insufficient for protecting Rhizobium from Zn toxicity effects.
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| 7. |
- Deak Sjöman, Johanna, et al.
(författare)
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Branch Area Index of Solitary Trees: Understanding Its Significance in Regulating Ecosystem Services
- 2016
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 45, s. 175-187
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Tidskriftsartikel (refereegranskat)abstract
- The chief aim of this study was to investigate how different species of solitary trees in temperate urban areas vary in their branch structure during winter by assessing branch area indices (BAIs). The BAI data showed significant differences (P < 0.0001) between species and genotypes. The lowest mean BAI in the dataset was for Gingko biloba L., which had a BAI of 0.27. Pinus strobus L. `Fastigiata ' represented the largest mean BAI of 2.09. The results from the BAI analysis further indicate that within the same species group differences occur between genotypes. For example, the five genotypes of Acer platanoides L. range from a mean BAI of 1.77 for A. platanoides `Globosum' to a mean BAI of 0.50 for A. platanoides `Fassen Black'. A further aim was to apply the compiled BAI data in the computational modeling program of ENVI-met 3.1, which simulates the surface-air interaction and microclimates in complex urban settings. The simulations focused on mean radiant temperature and wind speed. Results illustrate how wind speed on the leeward side of the trees gradually decrease with an increasing BAI. With an increasing BAI, the Tmrt decreases to the leeward of the row of trees. The results are further discussed in the perspective of sustainable urban development (i.e., where, why, and how the species studied could be integrated in the urban fabric). This is of particular interest for the design of urban green space in densely built-up urban environments where space may be restricted.
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| 8. |
- Djodjic, Faruk, et al.
(författare)
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A Global Perspective on Phosphorus Management Decision Support in Agriculture: Lessons Learned and Future Directions
- 2019
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 48, s. 1218-1233
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of phosphorus (P) management decision support tools (DSTs) and systems (DSS), in support of food and environmental security has been most strongly affected in developed regions by national strategies (i) to optimize levels of plant available P in agricultural soils, and (ii) to mitigate P runoff to water bodies. In the United States, Western Europe, and New Zealand, combinations of regulatory and voluntary strategies, sometimes backed by economic incentives, have often been driven by reactive legislation to protect water bodies. Farmer-specific DSSs, either based on modeling of P transfer source and transport mechanisms, or when coupled with farm-specific information or local knowledge, have typically guided best practices, education, and implementation, yet applying DSSs in data poor catchments and/or where user adoption is poor hampers the effectiveness of these systems. Recent developments focused on integrated digital mapping of hydrologically sensitive areas and critical source areas, sometimes using real-time data and weather forecasting, have rapidly advanced runoff modeling and education. Advances in technology related to monitoring, imaging, sensors, remote sensing, and analytical instrumentation will facilitate the development of DSSs that can predict heterogeneity over wider geographical areas. However, significant challenges remain in developing DSSs that incorporate "big data" in a format that is acceptable to users, and that adequately accounts for catchment variability, farming systems, and farmer behavior. Future efforts will undoubtedly focus on improving efficiency and conserving phosphate rock reserves in the face of future scarcity or prohibitive cost. Most importantly, the principles reviewed here are critical for sustainable agriculture.
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| 9. |
- Larsbo, Mats, et al.
(författare)
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Surface Runoff of Pesticides from a Clay Loam Field in Sweden
- 2016
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 45, s. 1367-1374
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Tidskriftsartikel (refereegranskat)abstract
- Pesticides stored at or close to the soil surface after field application can be mobilized and transported off the field when surface runoff occurs. The objective of our study was to quantify the potential pesticide losses in surface runoff from a conventionally managed agricultural field in a Swedish climate. This was achieved by measuring surface runoff volumes and concentrations in runoff of six spring-applied pesticides and autumn-applied glyphosate and its metabolite aminomethylphosphonic acid (AMPA). Measurements were performed for 3 yr both during the growing seasons and during intervening winter snowmelt periods on a clay loam field close to Uppsala. During growing seasons, surface runoff was generated on only five occasions during one 25-d period in 2012 when the infiltration capacity of the soil may have been reduced by structural degradation due to large cumulative rainfall amounts after harrowing. Concentrations in surface runoff exceeded Swedish water quality standards in all samples during this growing season for diflufenican and pirimicarb. Surface runoff was generated during three snowmelt periods during the winter of 2012-2013. All of the applied pesticides were found in snowmelt samples despite incorporation of residues by autumn plowing, degradation, and leaching into the soil profile during the period between spraying and sampling. Concentrations of glyphosate ranged from 0.12 to 7.4 mg L-1, and concentrations of AMPA ranged from 0 to 2.7 mg L-1. Our results indicate that temporal changes in hydraulic properties during the growing season and when the soil freezes during winter affect pesticide losses through surface runoff.
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| 10. |
- Linefur, Helena, et al.
(författare)
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The Role of Subsoil as a Source or Sink for Phosphorus Leaching
- 2015
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 44, s. 535-544
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Tidskriftsartikel (refereegranskat)abstract
- The importance of subsoil features for phosphorus (P) leaching is frequently mentioned, but subsoil effects are still poorly documented. This study examined whether the subsoil of four agricultural Swedish soils (two sand and two clay) functioned as a source or sink for P leaching by measuring P leaching from intact soil columns with topsoil (1.05 m deep) and without topsoil (0.77 m deep) over 3 yr. One sandy soil with high topsoil P content (Olsen P, 84 mg kg(-1)) and high subsoil sorption capacity (P sorption index [PSI], 3.7 mmol kg(-1)) had low leaching of dissolved reactive P (DRP) from full-length and subsoil lysimeters (0.12 and 0.08 kg ha(-1) yr(-1), respectively). The other sandy soil, with high Olsen P content in the topsoil and subsoil (27 and 19 mg kg(-1), respectively) and low PSI in the subsoil (1.4 mmol kg(-1)), had high DRP leaching from full-length and subsoil lysimeters (3.33 and 3.29 kg ha(-1) yr(-1), respectively). High P content at depth (Olsen P, 21 mg kg(-1)) in one clay soil resulted in relatively higher subsoil DRP contribution (89%) to total leaching than observed in the other clay soil (71%). These results indicate that the subsoil can act as source or sink for P leaching, depending on P content, degree of P saturation, and P sorption capacity, and therefore subsoil properties should be considered when selecting mitigation measures to reduce P leaching.
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| 11. |
- Luo, Ziteng, et al.
(författare)
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Roots-Enhanced Preferential Flows in Deciduous and Coniferous Forest Soils Revealed by Dual-Tracer Experiments
- 2019
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425. ; 48:1, s. 136-146
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Tidskriftsartikel (refereegranskat)abstract
- Macropores formed by roots are crucial channels for preferential flows in forest soils that are largely responsible for water percolation and solute leaching. Using dual-tracer experiments (Brilliant Blue FCF and bromide [Br]), this study investigated the preferential flows of water and solutes in a deciduous forest dominated by Bl. and a coniferous forest mainly planted with (L.) Franco. Dye-stained patterns and concentrations of Brilliant Blue and Br were obtained in vertical soil profiles (0-30 cm), whereas stained and unstained roots were collected and analyzed in horizontal soil profiles to a 30-cm soil depth. Brilliant Blue and Br were mainly accumulated in the 0- to 20-cm soil depth, which had greater total root length density than the 20- to 30-cm soil depth ( < 0.05). Only part of the roots facilitated the preferential flows, with finer roots (i.e., diameter <1 mm) contributing the most. More intriguingly, the coniferous forest soil had a greater degree of preferential flows and greater tracer concentrations at deeper soil depth than the deciduous forest soil, suggesting the importance of tree species and forest composition on water and solute transport in forest ecosystems.
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| 12. |
- Parvage, Masud, et al.
(författare)
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Can organic materials reduce excess nutrient leaching from manure-rich paddock soils?
- 2017
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 46, s. 105-112
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Tidskriftsartikel (refereegranskat)abstract
- Horse paddocks have been identified as a significant contributor of animal waste nutrients to natural waters; thus, modified paddock management is needed. Because chemical amendments pose a health risk to horses, an alternative for reducing nutrient translocation from manure is to add available organic residues to the soil. To examine the feasibility of outdoor use of organic materials to reduce nutrient losses from paddock soils, three commonly available organic materials (peat, wheat straw, and wood chips) were tested for their nutrient retention capacities in batch experiments followed by leaching experiments in an in-house lysimeter station using artificial rainfall. Results showed that the grounded peat and wood chips retained some phosphorus (P), whereas grounded wheat straw released P to the solution. In leaching experiments, peat reduced nitrogen (N) losses by 40% but increased P and carbon (C) losses severalfold. Wheat straw was ineffective in reducing P, N, or C losses and in some cases increased the losses. Wood chips effectively reduced P and C losses, by 70 and 40%, respectively, but not N losses. It was concluded that, among the three organic materials, only the wood chips can be used outdoors to reduce nutrient losses from paddock soils.
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| 13. |
- Riddle, Matthew, et al.
(författare)
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Phosphorus Leaching from an Organic and a Mineral Arable Soil in a Rainfall Simulation Study
- 2018
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 47, s. 487-495
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorus derived from agricultural systems has been found to cause eutrophication of surface waters. To combat this, the specific location of soil profile P release is necessary for development of effective mitigation strategies. This paper describes a P leaching study of two Swedish arable soils, an organic (Typic Haplosaprist) and a mineral soil (Typic Hapludalf), both with high P content. Undisturbed soil columns isolated 0- to 20-, 20- to 40-, 40- to 60-, and 60- to 80-cm depth intervals. These were placed in a rainfall simulator and subjected to four 50-mm rainfall events to identify the origin of P leachate as a function of soil depth interval and physicochemical properties. Phosphorus losses were greatest from the two uppermost layers of both soils after 200 mm of artificial rainfall was applied at 5 mm h(-1). Total P concentration in leachate from the 0- to 20-cm layer ranged from 2.1 to 8.8 mg L-1 for the mineral and 3.7 to 10.3 mg L-1 from the organic soil, with most (95-100%) in dissolved reactive P form. Degree of P saturation correlated well with total P leaching losses from the organic soil (R = 0.84) but not the mineral soil (R = 0.69), suggesting that the presence of Al and Fe (hydr) oxides has a stronger influence on P leaching in the organic soil. Results indicate that both soils have the potential to contribute concentrations of P above those known to cause eutrophication of surface waters.
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| 14. |
- Ulen, Barbro, et al.
(författare)
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Impact of the North Atlantic Oscillation on Swedish Winter Climate and Nutrient Leaching
- 2019
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 48, s. 941-949
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Tidskriftsartikel (refereegranskat)abstract
- The winter climate in northwestern Europe is commonly influenced by the North Atlantic Oscillation (NAO). Its intensity, expressed as an index (NAO(i)), has been suggested for use in assessing nutrient leaching from arable land to water and the effects of mitigation measures. We found significant (p < 0.05) positive linear relationships between NAO(i) and an air freezing-thawing index in central and southern Sweden for 2004 to 2016. This period covered winters with both extreme low and high NAO(i.) There were significant negative linear relationships between NAO(i) and a snow depth index. Management and nutrient leaching were studied simultaneously in two agricultural catchments (20.7 ha, code 11M; 788 ha, code M36) in southwestern Sweden. Catchments 11M (silty-clay soil) and M36 (sandy hills with a central, heavy clay plain) are both artificially drained. Total N and total P leaching increased significantly with winter (November-April) NAO(i) in both catchments. In contrast, leaching of dissolved reactive P (DRP) was not related to NAO(i). The highest DRP concentrations were observed in connection with specific agricultural practices, whereas moderately elevated DRP concentrations were linked to snowmelt events. Concentrations of P in other forms (other P) were even more elevated (1.02 mg L-1) in 11M in winter 2014-2015, probably due to a large (32% of area) internal buffer (ley-fallow) in a central ravine being plowed down in autumn 2014. No general trend in P or N fertilization was found in catchment M36. Thus NAO(i) may be appropriate for use in trend analyses of nutrient load in the study region.
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| 15. |
- van Grinsven, Hans J. M., et al.
(författare)
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Losses of Ammonia and Nitrate from Agriculture and Their Effect on Nitrogen Recovery in the European Union and the United States between 1900 and 2050
- 2015
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 44:2, s. 356-367
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Tidskriftsartikel (refereegranskat)abstract
- Historical trends and levels of nitrogen (N) budgets and emissions to air and water in the European Union and the United States are markedly different. Agro-environmental policy approaches also differ, with emphasis on voluntary or incentive-based schemes in the United States versus a more regulatory approach in the European Union. This paper explores the implications of these differences for attaining long-term policy targets for air and water quality. Nutrient surplus problems were more severe in the European Union than in the United States during the 1970s and 1980s. The EU Nitrates and National Emission Ceilings directives contributed to decreases in fertilizer use, N surplus, and ammonia (NH3) emissions, whereas in the United States they stabilized, although NH3 emissions are still increasing. These differences were analyzed using statistical data for 1900-2005 and the global IMAGE model. IMAGE could reproduce NH3 emissions and soil N surpluses at different scales (European Union and United States, country and state) and N loads in the Rhine and Mississippi. The regulation-driven changes during the past 25 yr in the European Union have reduced public concerns and have brought agricultural N loads to the aquatic environment closer to US levels. Despite differences in agro-environmental policies and agricultural structure (more N-fixing soybean and more spatially separated feed and livestock production in the United States than in the European Union), current N use efficiency in US and EU crop production is similar. IMAGE projections for the IAASTD-baseline scenario indicate that N loading to the environment in 2050 will be similar to current levels. In the United States, environmental N loads will remain substantially smaller than in the European Union, whereas agricultural production in 2050 in the United States will increase by 30% relative to 2005, as compared with an increase of 8% in the European Union. However, in the United States, even rigorous mitigation with maximum recycling of manure N and a 25% reduction in fertilizer use will not achieve the policy target to halve the N export to the Gulf of Mexico.
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