FREE ELECTRONIC LIBRARY - Dissertations, online materials

Pages:     | 1 |   ...   | 31 | 32 || 34 | 35 |   ...   | 92 |

«International 17 Workshop th Nitrogen The was jointly organised by Teagasc and AFBI Printed by Print Depot Suggested citation Authors, 2012. Title ...»

-- [ Page 33 ] --

4. Conclusion The leaching increased by 0-15 kg N ha-1 after application of slurry in autumn compared to no slurry application or application in spring with no significant difference in leaching depending on how late in autumn slurry was applied. Since the effect on leaching was significant only when application rates were higher than intended (60 kg ha-1), autumn application may be appropriate as long as rates are limited. However, more results are needed before such limits can be defined.

References Djurhuus, J. 1990. Sammenligning af nitrat i jordvand udtaget med sugkopper og ekstrahert fra jordprøver.

Landbrugsministeriet, Statens Planteavlsforsøg, Særtryk af Tidsskrift for Planteavl 94, 487-495.

EEC, 1991. Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources

Nitrogen Workshop 2012

Nitrogen dynamics in agricultural Mediterranean catchments vs. temperate ones: Ebro, Oglio, Seine and Scheldt comparisons Lassaletta, L.a,b, Bartoli, M.c, Billen, G.a, Garnier, J.a, Grizzetti, B.a, Romero E.a, Soana E.c, Viaroli, P.c a CNRS/UPMC, UMR 7619 Sisyphe, 4 place Jussieu, 75005 Paris, France b Department of Ecology, Universidad Complutense de Madrid, c/ José Antonio Novais 28040 Madrid, Spain c Department of Environmental Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124 Parma, Italy

1. Background & Objectives Ecological processes in regions with Mediterranean climates are affected in different ways than those subject to other climatic conditions. N inputs in Mediterranean catchments have been estimated to be lower than those in temperate European catchments (Grizzetti et al., 2011) but this does not fully justify the very low N loads finally exported to the Mediterranean Sea. Romero et al.

(submitted) have recently shown how N fluxes from Mediterranean catchments to the sea are on average over two times lower than those observed in European temperate catchments. A recent study conducted in the Ebro, a characteristic Mediterranean catchment, has shown that a high proportion of all N inputs never reach the sea, and this is due to the particular management that tipyfies agricultural areas in this type of climate (Lassaletta et al., 2012). On the other hand, in the Oglio, an affluent of the Po river, Bartoli et al. (2012) have estimated one of the highest fluvial N exports observed in a river outlet. The main objective of the present work is to synthesize and compare the information on N dynamics and retention from two Mediterranean and two temperate catchments, and to identify the main discrepancies and similarities.

2. Materials & Methods Four highly monitored catchments have been chosen: two under Mediterranean climate (the Ebro and the Oglio River Basins, in Spain and Italy respectively) and two in temperate areas (the Seine and the Scheldt River Basins, in France and Belgium) (Table 1). These catchments are relatively homogeneous in terms of agricultural surface but rather heterogeneous in terms of runoff, population density and livestock uses. We performed a soil system balance (Lassaletta et al., 2012) in the agricultural areas to estimate diffuse sources. Point sources and N retention in the catchment where also estimated based on national statistics. The term “retention” is used to designate all the processes preventing nitrogen load from being transferred to the outlet of the drainage network.

–  –  –

This unusual high retention has been related to the intense water regulation (by means of numerous dams and channels) that characterizes Mediterranean semi-arid agricultural catchments (Lassaletta et al., 2012). The Oglio catchment represents an opposite case. Despite being located in a Mediterranean area, the runoff is the highest of the four catchments studied and this, together with the very high agricultural inputs, results in a high amount of N being exported outside the catchment. Bartoli et al. (2012) have shown, however, how the dense channel network typical of Mediterranean catchments can induce high N retentions and also high N2O emissions.

4. Conclusion Mediterranean catchments can have very high N retention percentages when the catchment is semiarid, highly regulated and has low runoff levels. Despite being located in Mediterranean areas, highly impacted catchments with high runoff values can present a behavior that is similar to that of catchments placed on temperate ecosystems. Nitrogen dynamics and some pollution-associated problems can be very different according to catchment characteristics such as climate and water regulation. Further research should address the fate of the nitrogen which is retained, in particular verify whether it is permanently lost via denitrification or temporarily accumulated in soils or in the groundwater.

References Bartoli, M., Racchetti, E., Delconte, C.A., Sacchi, E., Soana, E., Laini, A., Longhi, D. and Viaroli, P. 2012. Nitrogen balance and fate in a heavily impacted watershed (Oglio River, Northern Italy): In quest of the missing sources and sinks, Biogeosciences 9, 361-373.

Billen, G., Silvestre, M., Grizzetti, B., Leip, A., et al. C.: 2011. Nitrogen flows from European regional watersheds to coastal marine waters, in: The European Nitrogen Assessment, edited by: Sutton, M. A., et al. Cambridge University Press, New York, 271-297.

Grizzetti, B., Bouraoui, F. and Aloe, A. 2012. Changes of nitrogen and phosphorus loads to European seas. Global Change Biology 18, 769–782.

Lassaletta, L., Romero, E., Billen, G., Garnier, J., García-Gómez, H. and Rovira, J. V. 2012. Spatialized N budgets in a large agricultural Mediterranean watershed: High loading and low transfer. Biogeosciences 9, 57-70.

Romero E., Garnier J., Lassaletta L., Billen G., Le Gendre R., Riou P. and Cugier P. 2012. Large-scale patterns of river inputs in SW Europe: seasonal and interannual variations and potential eutrophication effects, Biogeochemistry, submitted.

Nitrogen Workshop 2012

Nitrogen dynamics in maize based cropping systems for biogas production Sieling, K.a, Herrmann, A.b, Wienforth, B.a, Ohl, S.c, Taube, F. b, Kage, H.a a Institute of Crop Science and Plant Breeding; Agronomy and Crop Science; Christian-Albrechts-University, Kiel, Germany b Institute of Crop Science and Plant Breeding; Grass and Forage Science/Organic Agriculture; Christian-AlbrechtsUniversity, Kiel, Germany c Institute of Agricultural Engineering; Christian-Albrechts-University, Kiel, Germany

1. Background & Objectives Biogas production has gained importance as a contribution to climate change mitigation, notably in Germany. Biogas residues (BR), which are produced in large amounts, thus should be used in a sustainable way. Anaerobic digestion was shown increase the short-term N availability (Gutser et al., 2005), but also to promote ammonia emission (Gericke, 2009). Data on the fertiliser value of BR from co-fermentation is still limited. This paper aims to investigate the N supplying potential of co-digestion residues to maize monoculture and a maize rotation in terms of N balance, methane yield, and apparent N recovery (ANR), based on a 2-year field trial conducted in northern Germany.

2. Materials & Methods A 2-year field trial (2007-2009) was established as 4-factorial randomized block design with 4 replicates at Hohenschulen experimental station (750 mm, 8.3°C; luvisol) of Kiel University.

Treatments comprised crop rotation (R1: maize monoculture, R2: maize-whole crop winter wheatItalian ryegrass as catch crop), N fertilizer type (calcium ammonium nitrate (CAN), biogas residue (Mix), pig slurry (Pig)), and N amount (maize, wheat: 0, 120, 240, 360 kg N ha-1; Ital. ryegrass: 0, 80 kg N ha-1 for each of two cuts). Each crop of R2 was grown in each year. The N balance was calculated as difference between N fertilization and crop N offtake. Specific methane yield (SMY;

lN CH4 kg-1 OM) of the CAN and Mix treatments was obtained by the Hohenheim Biogas Yield Test (Helffrich and Oechsner, 2006). The relation between N amount and methane yield, N balance and ANR was quantified by SAS 9.2 Proc NLIN assuming a ‘Linear-Plateau’ model. Function parameters were compared by a modified t-test based on Zar (2009). Total N of organic fertilizers had been corrected for NH3-N losses during application as estimated by Gericke (2009).

3. Results & Discussion Methane yield production, N offtake and N balance were not affected by N fertilizer type, while rotation showed a significant impact on N dynamics and on maize yield performance. Maize monoculture achieved a maximum methane hectare yield of 6,774 m³N CH4 ha-1 at the N rate of 122 kg N ha-1 as Mix (Figure 1a). Rotation R2 had a significantly lower yield of 5,302 m³N CH4 ha-1, which, however, required an N input of 257 kg N ha-1. The superiority in yield of R1 was due to higher dry matter yield of maize, while differences in SMY among crops were small. Higher N contents of wheat and Italian ryegrass resulted in higher N offtake of R2 compared to R1 (Figure 1b). However, R2 required a significantly higher N input to achieve its N offtake maximum, whereas for the unfertilized control, N offtake of R2 was considerably lower than for R1.

Consequently, the N balance at N input required for maximum methane yield (Nopt) was significantly lower for R1 (Figure 1c). The apparent N recovery (ANR) of R2 remained constant at values of 72% (CAN), 63% (Mix), and 70% (Pig) for N input below 250 kg N ha-1 (CAN, Pig) or 280 kg N ha-1 (Mix) (Fig. 1d), whereas it decreased nonlinearly above, resulting in similar curves for all fertilizer types. Mix applied to R2 revealed a short-term N fertilizer value below that of pig slurry, which is in accordance to the lower NH4-N content of Mix (53.0%) compared to pig slurry

Nitrogen Workshop 2012

(72.0%) and a higher NH3 volatilization (Gericke, 2009). For R1, however, Mix showed a higher fertilizer value than Pig. This might be due to different temporal characteristics of N leaching, although the total leaching loss observed over the 2-year period was similar for Mix and Pig (Svoboda, 2011). Higher mineralization of organically bound N in Mix, due to a lower C/N ratio, and non-N effects seem unlikely. Because of their high plant N availability, BR, as liquid animal manure, present a considerable risk of nitrate leaching when the amount and timing of N fertilization is not adjusted to meet crop N demand. Mitigation of nitrate leaching by growing maize in a crop rotation proved effective in case of N oversupply (Svoboda, 2011).

A B Methane yield [m3 ha-1]

–  –  –

Figure 1. Average annual methane yield (m³N CH4 ha-1) (a), N offtake (b), N balance (c) and apparent N recovery (ANR) (d) of crop rotations R1 (thin lines, open symbols) and R2 (bold lines, closed symbols) fertilized with varying amounts of mineral N (solid lines, circles), biogas residue (broken lines, triangles) and pig slurry (dotted lines, squares).

4. Conclusion BR provide a valuable nutrient source which can reduce GHG emissions when replacing fossil fuel based fertilizer. If properly managed, they do not increase the risk of environmental impact compared to liquid animal manure. Long-term effects need to be evaluated by model simulations.

References Gericke D. 2009. Measurement and modelling of ammonia emissions after field application of biogas slurries. Doctoral thesis, Christian-Albrechts-Universität, Kiel, German.

Gutser, R., Ebertseder, T., Weber, A., Schraml, M. and Schmidhalter U. 2005. Short-term and residual availability of nitrogen after long-term application of organic fertilizers on arable land. J. of Plant Nutrition and Soil Science 168, 439Helffrich D. and Oechsner H. 2003. The Hohenheim Biogas Yield Test. Landtechnik 58, 148-149.

Svoboda N. 2011. Auswirkung der Gärrestapplikation auf das Stickstoff-Auswaschungspotential von Anbausystemen zur Substratproduktion. Doctoral thesis, Christian-Albrechts-Universität, Kiel, Germany Zar, J.H. 2009. Biostatistical Analysis. 5th Edition, Prentice Hall, 960 p.

Nitrogen Workshop 2012

Nitrogen losses from buffer zones: interactions with soil structure and hydrological pathways Carswell, A.M.a,b, Blackwell, M.S.Aa, Bol, R.a, Chadwick, D.a, Hawkins, J.M.B.a, Johnes, P.b, Whalley, R.c a Rothamsted Research, North Wyke, Okehampton, Devon, U.K.

b University of Reading, Whiteknights, Reading, Berkshire, U.K.

c Rothamsted Research, West Common, Harpenden, Hertfordshire, U.K.

1. Background & Objectives Pollution of surface waters by agriculturally derived nutrients, especially nitrogen (N) and phosphorus (P), is well known to cause eutrophication and has implications for drinking water quality. Implementation of buffer zones, at the downslope edge of agricultural fields, to mitigate diffuse nutrient pollution of surface waters is endorsed by Defra (Department for Environment, Food and Rural Affairs), as an option to gain Entry Level Stewardship status (Defra, 2010), whereby grants are awarded for environmentally beneficial land management techniques. However, hydrological bypassing, via artificial drainage, is known to reduce the efficacy of buffer zones (Leed-Harrison et al., 1999). Installation of a permeable reactive barrier (PRB) to intercept artificial drainage flow has the potential to increase flow residence time and provide optimal conditions for nutrient capture or transformation (Schipper et al., 2010; Grimsey, 2011) within the buffer zone.

The objectives of this study are to examine two key questions (1) whether the drained buffer zone works to capture and transform different N forms; and (2) whether installation of PRBs within buffer zones can be used to intercept drainage flow and encourage full denitrification of potential surface water pollutants. The application and examination of the efficiency of PRBs in conjunction with a buffer zone in a drained intensive grassland makes this work innovative, especially with regard to the replication and large scale at which investigations are being carried out (see below).

2. Materials & Methods The study site is the North Wyke Buffer Zone Experiment, Rothamsted Research, Devon, England.

Pages:     | 1 |   ...   | 31 | 32 || 34 | 35 |   ...   | 92 |

Similar works:

«Richard Osborne Colonial Film Essays The homepage for the essays is located at: http://www.colonialfilm.org.uk/. The web address for each essay is included in the individual entries. 2 Contents 2ND BATTALION 4TH BOMBAY GRENADIERS IN INDIA, CA 1930 2ND BATTALION WELCH REGIMENT IN INDIA CELEBRATE GHELUVELT DAY, 1933 A DAY IN CEYLON A NATIVE STREET IN INDIA A ROAD IN INDIA A STRING OF BEADS A TEA GARDEN IDYLL A VILLAGE IN INDIA ACHIEVEMENT IN HONG KONG AIR FORCE AND JAPS DOWNED, BURMA, 30 JANUARY...»

«Linköping Studies in Science and Technology Dissertation No. 1106 Discrete and Continuous Shape Writing for Text Entry and Control Per Ola Kristensson Department of Computer and Information Science Linköping University 581 83 Linköping, Sweden Linköping 2007 ISBN 978-91-85831-77-7 ISSN 0345-7524 Printed by LiU-Tryck, Linköping 2007 Abstract Mobile devices gain increasing computational power and storage capabilities, and there are already mobile phones that can show movies, act as digital...»

«Answers from the Crowd: How Credible are Strangers in Social Q&A? Grace YoungJoo Jeon1 and Soo Young Rieh1 School of Information, University of Michigan 1 Abstract Individuals may encounter distinct kinds of challenges in assessing credibility in a social Q&A setting where they interact with strangers. It is necessary to better understand how people make credibility judgments when seeking information using social Q&A services because people increasingly use such services to obtain personalized...»

«TEXAS ETHICS COMMISSION PERSONAL FINANCIAL STATEMENT FORM PFS INSTRUCTION GUIDE Revised October 20, 2016 Texas Ethics Commission, P.O. Box 12070, Austin, Texas 78711 (512) 463-5800 FAX (512) 463-5777 TDD 1-800-735-2989 Visit us at https://www.ethics.state.tx.us on the Internet. AN EQUAL OPPORTUNITY EMPLOYER The Texas Ethics Commission does not discriminate on the basis of race, color, national origin, sex, religion, age or disability in employment or the provision of services. PERSONAL...»

«POLIC Y THE ICRC ITS MISSION AND WORK REFERENCE International Committee of the Red Cross 19, avenue de la Paix 1202 Geneva, Switzerland T + 41 22 734 60 01 F + 41 22 733 20 57 E-mail: shop.gva@icrc.org www.icrc.org © ICRC, March 2009 THE ICRC ITS MISSION AND WORK CONTENTS I. The ICRC’s mission 3 II. The ICRC’s identity 6 III. Scope of work and criteria for taking action 11 IV. Strategies for fulfilling the mission: From comprehensive analysis to specific activities 13 V. Coordination of...»

«journal of visual culture Visual Testimony: Lee Miller’s Dachau Sharon Sliwinski Abstract This essay examines images of the liberation of Dachau concentration camp taken by American war correspondent and photographer Lee Miller. Miller’s work is mobilized as an optic through which to grasp the shock of confronting the Nazi camps. Her images are read as a form of visual testimony. That is, although they fail to provide a transparent view of what occurred in the Nazi lagers, they are...»

«CURRICULUM VITAE Devin K. Binder, M.D., Ph.D. EDUCATION/PROFESSIONAL POSITIONS UNIVERSITY OF CALIFORNIA Riverside, CA Assistant Professor, Center for Glial-Neuronal Interactions, Division of Biomedical Sciences. Director, Translational Neuroscience Laboratory. Assistant Clinical Professor of Neurological Surgery, UCR-UCLA Thomas Haider Program in Biomedical Sciences. January 2010–present. BRAIN AND ELECTIVE SPINE TREATMENT (B.E.S.T.) CENTER Newport Beach, CA Neurosurgeon specializing in deep...»

«Tan Sri Datuk Dr. Abdul Samad Haji Alias Chairman Malaysia Deposit Insurance Corporation (MDIC) Tan Sri Datuk Dr. Abdul Samad Haji Alias was appointed as the Chairman of MDIC on 15 August 2011 and his current term of appointment continues until 14 August 2017. A Fellow of the Institute of Chartered Accountants in Australia, Tan Sri Datuk Dr. Abdul Samad has had extensive experience in auditing and accounting. He is a member of the Malaysian Institute of Certified Public Accountants and the...»

«Geology of the northern Plomosa Mountain range, Yuma County, Arizona Item type text; Dissertation-Reproduction (electronic) Authors Jemmett, Joe Paul, 1925Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author....»

«Journal of Organizational Behavior J. Organiz. Behav. 23, 363–382 (2002) Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/job.147 Generational differences: revisiting generational work values for the new millennium KAREN WEY SMOLA1* AND CHARLOTTE D. SUTTON2 1 Troy State University, University College, Southeast Region, U.S.A. 2 Department of Management, Auburn University, U.S.A. As we enter the new millennium and face the entrance of another generation of...»

«Saint-Constant PROVINCE DE QUÉBEC VILLE DE SAINT-CONSTANT RÈGLEMENT NUMÉRO 1016-16 RELATIF AUX ANIMAUX PROPOSÉ PAR: madame Louise Savignac APPUYÉ DE: monsieur Thierry Maheu ET RÉSOLU À L'UNANIMITÉ VERSION DU : 24 février 2016 AVIS DE MOTION : 12 avril 2016 ADOPTION DU RÈGLEMENT : 10 mai 2016 ENTRÉE EN VIGUEUR : 18 mai 2016 CONSIDÉRANT que la Régie intermunicipale de police Roussillon, dessert les municipalités de Candiac, Delson, La Prairie, Saint-Constant, Saint-Mathieu,...»

«6th European LS-DYNA Users’ Conference Modeling Hailstone Impact onto Composite Material Panel Under a Multi-axial State of Stress Authors Marco ANGHILERI * Luigi-M L CASTELLETTI * Andrea MILANESE * and Andrea SEMBOLONI * Affiliation * Politecnico di Milano, Department of Aerospace Engineering Via La Masa 34, 20156 Milano, Italia Correspondence Luigi-M L CASTELLETTI Phone: +39.02.2399.7155, Fax: +39.02.2399.7153 E-mail: luigi.castelletti@polimi.it ABSTRACT Flying through a hailstorm is...»

<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.