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The Effect of N Fertiliser forms on N2O emissions from UK arable and grassland. Experimental site in Dumfries, 2004

Related Party - Individual (Point of Contact): Professor R.M. Rees (SRUC)
Related Party - Organisation (Author): The University of Edinburgh
Related Party - Organisation (Author): SRUC
Related Party - Organisation (Funder): Defra
Nitrous oxide emissions (2 closed static chambers/plot) were monitored for about 12 months, following the spring application, by hand, of various nitrogen fertilisers (ammonium nitrate, urea, urea+urease inhibitor nBTPT [trade name Agrotain®], urea ammonium sulphate) and from an untreated control. Three fertiliser applications were made in order to achieve the target, commercial rate of 220 kg N/ha. There were 3 replicate plots (2 x 6 m) of each treatment arranged in a randomised block design. The plots were established on grassland, on a sandy loam soil in south west Scotland, UK. The Dumfries, 2004 experiment contains data sets of; annual nitrous oxide emissions, annual nitrous oxide emission factors, soil moisture, top soil mineral nitrogen, temperature, rainfall and associated crop & soil measurements.

Subject Keywords: Nitrous oxideManufactured nitrogen fertilizersAmmonium nitrateUrea fertilizersUrea ammonium sulphate fertilizersUrease inhibitorsGrassland soils
Geographic Keywords: Dumfries and GallowaySouth West ScotlandScotlandUnited Kingdom
Phenomenon Time -  Start Date/Time: 2004-03-10 00:00:00 End Date/Time:  2005-01-26 00:00:00

Geographic Extent -
    Longitude (West): -3.72
    Longitude (East): -3.46
    Latitude (South): 54.97
    Latitude (North): 55.13

Data Quality Statement:
SAC CONSULTING & SRUC RESEARCH QUALITY POLICY We aim to: - Ensure that all Consulting & Research contracts and services are fulfilled in a professional manner and that the requirements and expectations of our clients are met. - Be effective in translating the outcomes of our work into practice and cascading this on to appropriate industry partners. - Achieve a work environment that is professional, creative and enjoyable to work in and is in accordance with the organisations RISE values. - Ensure that management communicate the requirements of the Quality Management Systems and their roles and responsibilities in terms of its implementation and maintenance, while also ensuring that sufficient resources are in place to effectively maintain the Quality Management System. This incorporates: 1. Efficient processes for carrying out the highest quality Consulting & Research work, to inspire stakeholders and to meet individual clients’ needs. 2. Having defined roles and responsibilities across SAC Consulting & SRUC Research, to assist staff in their every day work 3. Senior managers maintain a commitment to attract and develop high quality, dedicated staff through on going investment in our resources and training, while also maintaining a working environment that lends itself to high quality Consulting and Research work. 4. Completion of projects to expectation through systems of quality control that ensure safe, effective and economic use of resources and the ongoing review of completed work, to enable us to improve our processes and services available to clients. We are committed to ensuring that our Quality Management System continues to comply with the requirements of ISO 9001:2015 with the regular review of our quality objectives and the continuous improvement of our systems, which will be led and directed by senior managers within SAC Consulting and SRUC Research. We shall achieve this by developing in all staff a culture that ensures individual commitment to meeting client requirements and the achievement of identified objectives that ensure that the overall aims and objectives of the organisation continue to be met. Quality is everyone’s responsibility Signed: Date: 11th April 2016 Dr Mike Smith Head of Contracts Office Detailed nitrous oxide emission measurement methodology: Direct N2O emissions were measured with two static flux chambers (40 cm diameter; 20 cm high) per plot, covering a total surface area of 0.252 m2. The chambers were circular chambers made of opaque polypropylene and sealed using aluminium lids (fitted with a rubber seal) and clips to form an air tight seal. Chambers were pushed into the soil up to a depth of 5 cm and remained in place throughout the experiment, except during fertiliser application and grass cutting when chambers were removed, locations were marked, and chambers were re-instated to the same position as prior to removal. Chambers remained open except for a short time on each sampling day. On that day, at least four samples of ambient air were taken to represent time zero (T0) N2O samples. From each chamber, after a 40-minute enclosure period (T40) two headspace samples were taken. Using a hand pump and a 3-way tap system each sample was flushed through a pre-evacuated 22 ml glass vial fitted with a chloro-butyl rubber septum and held at atmospheric pressure. The N2O flux was calculated using an assumed linear increase in N2O concentration from the ambient N2O concentration (T0) to the N2O concentration inside the chamber after 40-minutes enclosure (T40) (Chadwick et al., 2014). Throughout each experiment, the linearity of emissions through time was checked routinely from one randomly selected chamber. Samples were taken from each chamber at 10 min intervals commencing at closure i.e. T0 and spanning the T40 sampling time. In order to minimise the effect of diurnal variation, gas sampling was carried out where possible at the same time of day. Gas samples were analysed as soon as possible after collection (to minimise potential leakage) using gas chromatographs fitted with an electron-capture detector and an automated sample injection system. The gas chromatographs were calibrated on a daily basis using certified N2O standard gas mixtures. An exchange of samples of chamber air and standard gas mixtures between labs from the different research organisations involved in the NT26 programme who operated the GCs were carried out, to avoid the possibility of any bias in the results towards high or low values. Following fertiliser application, N2O flux measurements were carried out daily for the first 3 days, changing successively to 2-day intervals, then twice per week, and then weekly after the return of fluxes to the control level, continuing until the end of the 12 month sampling period. Prior to the first fertiliser application N2O measurements were taken to provide baseline information. This sampling schedule resulted in an annual total of c.50 sampling days starting from the day of the first fertiliser application. Measurements were taken over 12 months to follow IPCC good practice guidance and so that the results were directly comparable to the IPCC 2006 methodology default emission factor. Nitrous oxide fluxes from the two replicate chambers per plot were averaged. Cumulative fluxes were calculated using the trapezoidal rule to interpolate fluxes between sampling points. References: Chadwick, D.R., Cardenas, L., Misselbrook, T.H., Smith, K.A., Rees, R.M., Watson, C.J., Mcgeough, K.L., Williams, J.R., Cloy, J.M., Thorman, R.E. & Dhanoa, M.S. (2014). Optimizing chamber methods for measuring nitrous oxide emissions from plot-based agricultural experiments. European Journal of Soil Science 65, 295-307. Smith K.A., Dobbie K.E., Thorman R., Watson C.J., Chadwick D.R., Yamulki S. & Ball B.C. (2012). The effect of N fertilizer forms on nitrous oxide emissions from UK arable land and grassland. Nutrient Cycling in Agroecosystems 93, 127-149.
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Rights Statement

This data is published under the licence FBA Licence

Attribution: K.A. Smith, K.E. Dobbie and B.C. Ball

Citation of this data should be as follows:
K.A. Smith, K.E. Dobbie and B.C. Ball (2017): The Effect of N Fertiliser forms on N2O emissions from UK arable and grassland. Experimental site in Dumfries, 2004. Version:1. [dataset] Freshwater Biological Association [publisher]. doi:10.17865/ghgno713

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