Nutrient balances Anne Miek Kremer 07/08 2010

Content Response overview Planning Notes Format Coefficient revisions Missing data Dissemination 07/08-Oct-2010

Response overview: Data received: P national: CH, ES, HU, EE, UK, DE N national: CH, ES, HU, PL, SI, EE, UK, DE N regional: PL Response to enquiry: AT, NO, EL, IE Deadline: End of October 07/08-Oct-2010

Planning Evaluation of balances: Diredate recommendations Define scope Harmonisation of coefficients and data sources Metadata Methodological improvements Diredate recommendations Working Group March 2011 07/08-Oct-2010

Please note: P balance; unit = P (not P2O5). Excretion coefficients should not exclude volatilisation of N. Metadata (data source, type of data source, coefficients, coefficient revisions, notable trend breaks) . 07/08-Oct-2010

Please note: MS are kindly asked to send updated data on crop statistics to Eurostat. http://epp.eurostat.ec.europa.eu/portal/page/portal/statistics/search_database (apro_cpp). In future we will pre-fill balances: crop statistics, livestock statistics, land-use, fertiliser consumption. MS would only need to send: fertilisers consumption (excl manure, mineral fertilisers), coefficient revisions, grassland production, crop residues, seeds an planting material, manure withdrawals. Format. 07/08-Oct-2010

Example format format industrial crops 07/08-Oct-2010

Coefficient revisions They can reflect: Real change Change in methodology/data source etc 07/08-Oct-2010

Coefficient revisions – Real change Example: N-coefficient fattening pigs 2000 is 15 kg N/tonne and in 2010 13 kg N per tonne. Lineair regression: 2001 (14.8), 2002 (14.6), 2003 (14,4)….2009 (13.2). 07/08-Oct-2010

Coefficient revisions Revision does not reflect real change 07/08-Oct-2010

Coefficient revisions Revision does not reflect real change: Recalculate previous years with new coefficients. Detailed coefficients, detailed data on livestock/ crops previous years not available; assume constant distribution. 07/08-Oct-2010

Example New coefficients available from 2000 on bovine animals <1 year (30 kg N/head), bovine animals 1-2 years (50 kg N per head), bovine animals >2 years (70 kg N/head). Before 2000 data on animal numbers only available for the aggregate cattle. Recalculate 1999: -Cattle in 1999 = 1000 heads. -Average % of bovine <1 year (2000-2010)=30% Manure excretion bovine < 1 year in 1999 = 0.3*1000*30 = 9000 kg. 07/08-Oct-2010

Missing data Imputation: for instance linear regression or using data of previous year, or three year average. Please mark imputed data in blue. 07/08-Oct-2010

Dissemination 07/08-Oct-2010

Questions to MS Do members of the WG agree with: a) Coefficient revisions: In the case of a real change: - to recalculate years between old an new coefficient with coefficients corrected by linear regression? In case revision does not reflect real change: to recalculate all previous years using the new coefficients? If coefficients become available on a more detailed level, but data on livestock numbers/crop areas are not available in the same detail for previous years, to disaggregate the animal numbers using an estimate of the average distribution of animals within a group over time? b) Imputing missing data? c) Data to be disseminated in absolute quantities as shown in previous slide? 07/08-Oct-2010