Regional representativeness of nitrogen and phosphorus excretion factors Task 4 Hans Kros Alterra Workshop ‘Excretion factors’ Eurostat, Luxemburg, 28 March 2014

Objective Task 4 Objective Task 4: To analyse the appropriateness of estimating regional excretion factors for animal categories

Outline Need for regional differentiation of N and P excretion coefficients Analysis of the practical feasibility of a regional differentiation of N and P excretion coefficients An overall assessment of the feasibility of a regional differentiation of N and P excretion coefficients

Need for regional excretion coefficients Regional differentiation of N and P balances and losses: Relevant for NH3 emissions and NO3 and P leaching Regional differentiation of policy measures: Nitrate Vulnerable Zones (NO3) Natura 2000 sites (NH3)

Regional differences in N losses in EU De Vries et al., in: The European Nitrogen Assessment. Chapter 15, 2011.

Regional differences N excretion coefficients => a variation of ± 20%

Causes of regional differences Excretion coefficients may differ regionally because of: Animal breeds (e.g., large vs small; fast vs slow) Production systems (e.g., organic vs common) Production levels (e.g., high vs low) Feed composition (e.g. differences in N and P contents) Housing systems (free-range vs housed)

Assessment of regional differences For pigs and poultry the feeding regimes show a relatively low variability within the EU For cattle, differences in milk production, breeds and animal feed cause regional differences in excretion coefficients In Flanders, N excretion by dairy cows (kg N per head) is function of the areas (ha) of grassland and maize land per LU: Nexcretion = 38.2 + 265.5 × Grass + 101.2 × Maize R2 = 0.71  Wustenberghs et al. (2007)

Inventory of regional excretion coefficients Countries N excretion coefficients P excretion coefficients Belgium Yes: Flanders, Walloon and Brussels Denmark No, but feasible through available farm statistics Germany Yes: per bündesland (NEC) - Italy Yes, some regions do have region-specific rates Netherlands Yes, feasible through available farm statistics United Kingdom Yes, separate values for N. Ireland and Scotland Not available See task 1, country report

Downscaling national data to regions Needed information per region: Animal number per animal category Animal production per animal category Intake and composition of the animal feed Production levels and systems Generally available at regional level: Livestock numbers (at NUTS2) Estimations of N balances in Nitrate Vulnerable Zones

Downscaling livestock numbers For Reasonable for grazing animals Less good for pigs and poultry Neumann et al., 2009, Landscape Ecol., 2009

Downscaling grassland production Smit et al. Agricult. Sys., (2008)

Influencing factors: availability and uncertainty Livestock category Factor Effect on excretion 1) Data availability at regional scale 2) Uncertainty 3) Acquiring possibility 4)   P N Dairy cattle Feed intake ++ ± + Diet composition - Grazing time Milk production level Live weight gain N and P contents Other cattle ? Pigs Feed composition Phytase addition Fattening period Poultry Amino acid addition Egg yield 1) ++: Factor causing a large change; +: moderate change; 0: no or small effect; ? unknown 2) +: Available at regional scale; ±: only for some MS available at regional scale; 0: not available at regional scale; ? unknown 3) ++: Large uncertainty; +: moderately large uncertainty; 0: small uncertainty; ? unknown 4) Refers to whether available data can be used by third parties or that the use is restricted, e.g. due to privacy protection: +: Disclosable for regional applicability; -: undisclosable for regional applicability; ? unknown

Estimated costs of regional differentiation One-off costs Infrastructure: 2 fte, (coordination: 0.5 fte, protocol development: 0.5 fte, liaison and dbms: 1 fte) Collection of regional data per MS: 0.5 fte per MS 16 fte => ~ 650 k€ Yearly costs 0.08 fte (2 wk)+ 0.04 fte (1 wk)× 28 = 1.2 fte => ~ 50 k€ per year 1) based on mean loan EU of 40 k€ per year

Conclusions Regional excretion factors are needed for: Regional GNB and GPB Regional N and P losses Some countries already use regional specific excretion coefficients (variation ± 20%) Downscaling of excretion coefficients based on auxiliary data is promising for grazing animals, but less appropriate for pigs and poultry Estimated costs needed for regional data collection: 650 k€ of one-off costs 50 k€ of yearly costs

Recommendations To consider regional excretion coefficients especially for dairy and beef cattle To use regional excretion coefficients if differences between regional means are: >20%

Thank you

Downscaling Management data SEAMLESS: Agri-environmental Zones (AEnZ): subdivision of the European landscape into 238 relatively homogeneous units in view of agronomy (Elbersen et al., 2006; Kempen et al., 2007) Capri: down scaled farm management information for use at smaller spatial units. (Leip et al. Biogeosciences, 2008; Curr. Opin. Environ, 2011)