General Annex – Characterisation of pools and flows 1 Introduction This annex serves to provide a guidance common to all annexes (pool) on: A systematic nomenclature of pools and sub-pools including how a unique identifier is constructed How N flows are unambiguously identified Nitrogen compounds Nitrogen-containing materials serving as ‘matrix’ for N flows 2 Codification of pools and flows For the purpose of numerical handling an unique (numeric) ID must be given to each (sub)pool and flow. For the purpose of readability a unique (textual) code can be given to each (sub)pool and flow 2.1 Pools All pools have a two-letter code and a unique pool-ID, which conceptually follows the UNFCCC and NFR reporting of greenhouse gases and air pollutants. IDs that deviate systematically from these reporting guidelines is marked with an asterisks (e.g., 6* below). Deviation from the original sort order of the guidance document is caused by a general changeover in coding by UNFCCC, to move from a system of 6 categories to one of 5 categories. The pools that need to be considered include also the pool ‘Rest of the World’ for the quantification of flows that enter or exit the national boundaries. 1 2 3 4 5 6* 7* 8* 9* EF MP AG FS WS HS AT HY RW Energy and Fuels Materials and products (not used in your annex!) Agriculture Forest and Semi-natural Vegetation Waste Humans and Settlements Atmosphere Hydrosphere Rest of the world 2.2 Sub-pools All sub-pools have a two-letter code to be combined with the two-letter code of their parent pool as well as a one-letter code which is combined with the pool-ID and following conceptually the UNFCCC and NFR reporting systems. Also here CRF coding is maintained whenever possible, and asterisks denote a deviation from that principle. For example, the agriculture pool has three sub-pools: animal husbandry (AH or 3A), manure storage and management (MM or 3B) and soil management (SM or 3D). Note that for the sake of simplicity, sub-pools can be referred to also as ‘pools’, as long as they are clearly defined. ID 3A 3B 3D AH MM SM Agriculture Animal husbandry Agriculture Manure management and manure storage Agriculture Soil management To be completed authors of the guidance documents for the different pools! 2.3 Sub-sub pools. Many sub-pools need to be further sub-divided for the purpose of the construction of a NiNB. For example, data collection and calculation for the AGAH pool needs to be done at the level of animal types. The decision on the number of sub-sub pools and the level of detail depends on the national circumstances. If applicable, the annexes will contain some guidance to facilitate the choices to be made. The identification of sub-sub pools shall be done by a systematic approach: (1) Each sub-sub pool must be identified by a number, which is added to the ID code of the subpool. For example, dairy and non-dairy cattle could have the IDs 3A1 and 3A2. Again, the coding follows guidance as in CRF, as long as this is possible. (2) Further subdivision should be avoided – if absolutely needed, it should determined using lower case letters, e.g. 1A2f – again, following CRF when available, which will hardly be the case. Each sub-sub pool can be identified by a two-four letter ‘code’ that can be freely chosen by national NiNBs experts. Harmonisation between countries is nevertheless favorable, thus the annexes will contain some guidance, if applicable. For example, dairy and non-dairy cattle could be identified by the acronyms DAIR and NDAI or DC and NC, respectively. 3 Nitrogen contents For the identification of ‘what’ is flowing the following definitions are made: Nitrogen forms (see also main guidance document): There are thousands of individual chemical compounds containing nitrogen that are listed by Chemical Abstract Services (CAS). Nitrogen contents can be assessed from the chemical formulae by stoichiometry using the respective atomic and molecular weights (see e.g. Supplementary Information to Pelletier & Leip, 2014). Examples for important nitrogen forms are ammonia (NH3), nitrous oxide (N2O) or also total nitrogen (Ntot). Matrices: total nitrogen flows embedded in a matrix with a fixed N content. Examples for important matrices are food products (soft wheat, eggs, wood, explosives, ..). Methods are available to assess the respective nitrogen contents, which in practice will cover a range. In case the table lists N content estimates from different sources with ‘conflicting’ values, the expert shall identify those values that are most suitable for the national conditions. Media: Environmental nitrogen emissions often occur in a medium such as ‘exhaust fume’ or ‘surface water’ where the N content is variable and dynamic. Table xx presents calculated nitrogen contents for relevant nitrogen forms, and typical measured or estimated nitrogen contents of important matrices. These values shall be used to convert the flows of total mass of nitrogen form or matrix to the flow of mass of which is required for NNBs. Each nitrogen form or matrix is identified by a ‘code’. Table xx gives the code for the listed nitrogen forms and matrices. However, it is possible that NiNBs experts wish to include other matrices can do so, however harmonization between countries is nevertheless favorable. a) Nitrogen forms Acronym Chemical formula or source N2 N2 NH3 NH3 N content [%] 100 82.35 Nitrogen oxides1 Nitrous oxide Urea Ammonium nitrate Ammonium sulfate 20/20/20 fertilizer NOx N2O UREA AMMN AMMS 30.43 63.64 46.67 35.00 21.21 20 b) Matrix* State description Protein Acronym N content Data source [%] PROT 16 XXX Solid/liquid Egg Meat EGG MEAT 2.02 3.5-5.3 XXX XX -- Manure MANU 1-3 XXX Liquid/solid Milk MILK 0.5 XXX Liquid Polymer of different amino acids N mainly in egg protein N mainly in meat protein Urea or uric acid (for chicken manure) are important components N mainly in milk protein Molecular nitrogen Ammonia 1 NOx N2O (NH2)2CO NH4NO3 (NH4)2SO4 By definition, NOx emissions are expressed as mass of NO2 State Gas Gas (or aqueous solution) Gas Gas solid solid solid solid description in fertilizer fertilizer fertilizer fertilizer Wood WOOD 0.05 To be completed authors of the guidance documents for the different pools! *) Substance in which N is embedded xxx Solid Forest products 4 Flows All flows will be given in tons N per year. At a minimum, flows of more than 100 g N/person and year need to be reported by a given country. A nitrogen budget covers reactive nitrogen compounds only. Flows of molecular nitrogen (N2) and other fully unreactive forms (e.g., N in mineral oil, or in polymer fibers) need not to be considered – see details in the respective pool descriptions. For a unique identification of a flow the following information should be given: (1) (2) (3) (4) The pool the flow starts / is flowing out of (poolex) The pool the flow ends / is flowing into (poolin) The martix in which the nitrogen is transported between poolex and the poolin The nitrogen form of any other information considered relevant to distinguish, e.g. (i) the compound that flows between the ex-pool and the in-pool (if no information is given it is by default total N), (ii) additions like max (maximum) or min (minimum) etc. The first three topics are always required. The fourth information is required in case the first three are not uniquely identifying a flow, or if the NNB expert wishes to provide some additional information. Start and end pools should be indicated at the highest level of detail the flow has been quantified. For example, the start pool of manure excretion from fattening pigs would be AGAHPIGF. In the case of environmental emission flows, where a nitrogen form is transported in a medium, the matrix is considered to be the nitrogen form itself. Thus, information about poolex, poolin and the N form is required. In some cases, flows between the same pools and in the same matrix might use different pathways or different media, such as for example N emissions to the hydrosphere could use surface water or groundwater. If such distinctions are captured in a NNB, the fourth type of information is required. In analogy to the pool description, we employ the pool system with codes to mark starting and endpoint, as well as the code of the matrix. The codes of the four types of information are separated by dashes. Poolex Poolin Matrix* Other info Total code MP AGAHNDAI SOYC - MP- Annex Description where guidance is given 3 Soya cake in compound AGAHNDAISOYC AGSM AT NH3 AGSM-ATNH3 AGSM HY NO3 Runoff in AGSM-HYsurfaces NO3waters SURFW feed fed to non-dairy cattle from industrial processing Ammonia emission to the atmosphere from agricultural soil management surface water runoff NO3-N losses to the hydrosphere from agricultural soil management N2O-N More examples to be added. *) Substance in which N is embedded 5 References Pelletier, N., & Leip, A. (2014). Quantifying anthropogenic mobilization, flows (in product systems) and emissions of fixed nitrogen in process-based environmental life cycle assessment: rationale, methods and application to a life cycle inventory. The International Journal of Life Cycle Assessment, 19(1), 166–173. doi:10.1007/s11367-013-0622-0